December 2016Why Does a Man with Chronic Hypertension Post Rotor Cuff Repair Have Pulsation Over the Right Neck: MRI/MRA/MRV.
This is a 78-year-old right-handed business executive presenting with a three-year history of headaches, light headed sensations, and right arm pain that was thought to be bursitis. He went to his community hospital and was diagnosed with right rotator cuff injury requiring surgery. No X-rays or MRI studies and/or second opinion were obtained. Thereafter, he underwent right rotator cuff repair complicated by staphylococcus infection of the right acromioclavicular joint.
December 2016Brain White Matter Changes Associated with Urological Chronic Pelvic Pain Syndrome: Multisite Neuroimaging from a MAPP Case-control Study.
Huang L, Kutch JJ, Ellingson BM, Martucci KT, Harris RE, Clauw DJ, Mackey S, Mayer EA, Schaeffer AJ, Apkarian AV, Farmer MA.
Clinical phenotyping of urological chronic pelvic pain syndromes (UCPPSs) in men and women have focused on end organ abnormalities to identify putative clinical subtypes. Initial evidence of abnormal brain function and structure in male pelvic pain has necessitated large-scale, multisite investigations into potential UCPPS brain biomarkers. We present the first evidence of regional white matter (axonal) abnormalities in men and women with UCPPS, compared with positive (irritable bowel syndrome, IBS) and healthy controls. Epidemiological and neuroimaging data were collected from participants with UCPPS (n = 52), IBS (n = 39), and healthy sex- and age-matched controls (n = 61). White matter microstructure, measured as fractional anisotropy (FA), was examined by diffusion tensor imaging. Group differences in regional FA positively correlated with pain severity, including segments of the right corticospinal tract and right anterior thalamic radiation. Increased corticospinal FA was specific and sensitive to UCPPS, positively correlated with pain severity, and reflected sensory (not affective) features of pain. Reduced anterior thalamic radiation FA distinguished patients with IBS from those with UCPPS and controls, suggesting greater microstructural divergence from normal tract organization. Findings confirm that regional white matter abnormalities characterize UCPPS and can distinguish between visceral diagnoses, suggesting that regional axonal microstructure is either altered with ongoing pain or predisposes its development.
December 2016Increasing Appropriate BRCA1/2 Mutation Testing: The Role of Family History Documentation and Genetic Counseling in a Multidisciplinary Clinic.
Kishan AU, Gomez CL, Dawson NA, Dvorak R, Foster NM, Hoyt A, Hurvitz SA, Kusske A, Silver EL, Tseng C, McCloskey SA.
BACKGROUND: Findings show that 5-10 % of women with a diagnosis of breast cancer (BCa) have actionable genetic mutations. The National Comprehensive Cancer Network guidelines for testing to detect BRCA1/2 mutations include personal history (PH) variables such as age of 45 years or younger and a family history (FH) variables. Rates of FH documentation and overall rates of appropriate referral for genetic testing are low, ranging from about 30 to 60 %. The authors hypothesized that an upfront FH documentation and inclusion of a genetics counselor in a multidisciplinary clinic (MDC) setting would increase rates of appropriate referral for genetic testing. METHODS: The study enrolled 609 consecutive women with non-metastatic BCa seen in consultation between June 2012 and December 2015 at a multidisciplinary clinic. Rates of FH documentation and referral for genetic testing to detect BRCA1/2 mutations were assessed before and after inclusion of a genetic counselor in the MDC.
December 2016Upgrade Rates of High-risk Breast Lesions Diagnosed on Core Needle Biopsy: a Single-institution Experience and Literature Review.
Mooney KL, Bassett LW, Apple SK.
Optimal management of high-risk breast lesions detected by mammogram yielding atypical ductal hyperplasia, flat epithelial atypia, atypical lobular hyperplasia, lobular carcinoma in situ, and radial scar without atypia on core needle biopsy is controversial. This is a single-institution retrospective review of 5750 core needle biopsy cases seen over 14.5 years, including 249 (4.3%), 72 (1.3%), 50 (0.9%), 37 (0.6%), and 54 (0.9%) cases of atypical ductal hyperplasia, flat epithelial atypia, atypical lobular hyperplasia, lobular carcinoma in situ, and radial scar without atypia, respectively. Patient age, radiologic characteristics, needle gauge, and excision diagnoses were recorded. Of 462 high-risk cases analyzed, 333 (72%) underwent excision. Upgrade rate to ductal carcinoma in situ, pleomorphic carcinoma in situ, or invasive mammary carcinoma was 18% for atypical ductal hyperplasia, 11% for flat epithelial atypia, 9% for atypical lobular hyperplasia, 28% for lobular carcinoma in situ, and 16% for radial scar. Carcinoma diagnosed on excision was more likely to be in situ than invasive, and if invasive, more likely to be low grade than high grade. Overall, cases that were benign (vs high risk or carcinoma) on excision were less likely to have residual calcifications after biopsy (17% vs 27%, P=0.013), and more likely to have a smaller mass size (<1 cm) (82% vs 50%, P=0.001). On subgroup analysis, atypical ductal hyperplasia cases that were benign (vs high risk or carcinoma) on excision were more likely to have smaller mass size (<1 cm) (P=0.025). Lobular neoplasia diagnosed incidentally (vs targeted) on core needle biopsy was less likely to upgrade on excision (5% vs 39%, P=0.002). A comprehensive literature review was performed, identifying 116 studies reporting high-risk lesion upgrade rates, and our upgrade rates were similar to those of more recent larger studies. Careful radiological-pathological correlation is needed to identify high-risk lesion subgroups that may not need excision.
December 2016Automatic Classification of Ultrasound Screening Examinations of the Abdominal Aorta.
Morioka C, Meng F, Taira R, Sayre J, Zimmerman P, Ishimitsu D, Huang J, Shen L, El-Saden S.
Our work facilitates the identification of veterans who may be at risk for abdominal aortic aneurysms (AAA) based on the 2007 mandate to screen all veteran patients that meet the screening criteria. The main research objective is to automatically index three clinical conditions: pertinent negative AAA, pertinent positive AAA, and visually unacceptable image exams. We developed and evaluated a ConText-based algorithm with the GATE (General Architecture for Text Engineering) development system to automatically classify 1402 ultrasound radiology reports for AAA screening. Using the results from JAPE (Java Annotation Pattern Engine) transducer rules, we developed a feature vector to classify the radiology reports with a decision table classifier. We found that ConText performed optimally on precision and recall for pertinent negative (0.99 (0.98-0.99), 0.99 (0.99-1.00)) and pertinent positive AAA detection (0.98 (0.95-1.00), 0.97 (0.92-1.00)), and respectably for determination of non-diagnostic image studies (0.85 (0.77-0.91), 0.96 (0.91-0.99)). In addition, our algorithm can determine the AAA size measurements for further characterization of abnormality. We developed and evaluated a regular expression based algorithm using GATE for determining the three contextual conditions: pertinent negative, pertinent positive, and non-diagnostic from radiology reports obtained for evaluating the presence or absence of abdominal aortic aneurysm. ConText performed very well at identifying the contextual features. Our study also discovered contextual trigger terms to detect sub-standard ultrasound image quality. Limitations of performance included unknown dictionary terms, complex sentences, and vague findings that were difficult to classify and properly code.
December 2016Complications after Transcatheter Arterial Embolization for Pelvic Trauma: Relationship to Level and Laterality of Embolization.
Shi J, Gomes A, Lee E, Kee S, Moriarty J, Cryer H, McWilliams J.
PURPOSE: Transcatheter arterial embolization (TAE) is commonly used to control hemorrhage after pelvic trauma. Despite the procedures reported safety, there can be severe complications, mostly related to ischemia of embolized tissues. Our purpose was to examine the complications of trauma patients resulting from the embolization techniques utilized at our level 1 trauma center. MATERIALS AND METHODS: A retrospective chart review was conducted. One hundred and seven patients who underwent pelvic embolization between January 2003 and December 2013 were included. Patient demographics, ISS, angiography techniques, and major complications including gluteal and skin necrosis, wound breakdown, and deep infection were compared.
December 2016Facial Nerve Stimulation Following Cochlear Implantation for X-linked Stapes Gusher Syndrome Leading to Identification of a Novel POU3F4 Mutation.
Wester JL, Merna C, Peng KA, Lewis R, Sepahdari AR, Ishiyama G, Hosokawa K, Kumakawa K, Ishiyama A.
We report a case of a nine-year-old male who presented with facial nerve stimulation four years after cochlear implantation. Computed tomography was performed revealing a dilated internal auditory meatus and the cochlear implant electrode was found to be protruding into the fallopian canal at the level of the geniculate ganglion. Subsequent genetic analysis demonstrated X-linked deafness type 2 (DFNX2) caused by a novel c.769C > T nucleotide change in the POU domain, class 3, transcription factor 4 gene (POU3F4). Inactivation of electrodes 1 and 19-21 successfully abated facial nerve stimulation.
December 2016Evaluation of Cognitivity, Proinflammatory Cytokines, and Brain Magnetic Resonance Imaging in Minimal Hepatic Encephalopathy Induced by Cirrhosis and Extrahepatic Portal Vein Obstruction.
Yadav SK, Goel A, Saraswat VA, Thomas MA, Wang E, Marincola FM, Haris M, Gupta RK.
BACKGROUND AND AIMS: Minimal hepatic encephalopathy (MHE) is the mildest form of hepatic encephalopathy (HE) and is characterized by deficits in neurocognitive performance without any clinical symptoms of HE. In the current study, we aim to evaluate and compare the neurocognitive, biochemical, and brain magnetic resonance (MR) imaging changes between patients with cirrhotic MHE and extrahepatic portal vein obstruction (EHPVO) MHE. METHODS: Thirty-three cirrhotic and 14 EHPVO patients were diagnosed with MHE and were included in the analysis along with 24 normal healthy volunteers. All subjects underwent MR imaging including diffusion tensor imaging and proton MR spectroscopy (1 H-MRS) followed by cognitive assessments, critical flicker frequency (CFF) measurements, quantification of blood ammonia, and serum proinflammatory cytokine levels.
November 2016Dynamic Susceptibility Contrast MR Imaging in Glioma: Review of Current Clinical Practice.
Boxerman JL, Shiroishi MS, Ellingson BM, Pope WB.
Dynamic susceptibility contrast (DSC) MR imaging, a perfusion-weighted MR imaging technique typically used in neuro-oncologic applications for estimating the relative cerebral blood volume within brain tumors, has demonstrated much potential for determining prognosis, predicting therapeutic response, and assessing early treatment response of gliomas. This review highlights recent developments using DSC-MR imaging and emphasizes the need for technical standardization and validation in prospective studies in order for this technique to become incorporated into standard-of-care imaging for patients with brain tumors.
November 2016Knowledge-driven Decision Support for Assessing Dose Distributions in Radiation Therapy of Head and Neck Cancer.
Deshpande RR, DeMarco J, Sayre JW, Liu BJ.
PURPOSE: Clinical data that are generated through routine radiation therapy procedures can be leveraged as a source of knowledge to provide evidence-based decision support for future patients. Treatment planning in radiation therapy often relies on trial-and-error iterations, experience, judgment calls and general guidelines. The authors present a knowledge-driven decision support system that assists clinicians by reducing some of the uncertainties associated with treatment planning and provides quantified empirical estimates to help minimize the radiation dose to healthy critical structures surrounding the tumor. METHODS: A database of retrospective DICOM RT data fuels a decision support engine, which assists clinicians in selecting dose constraints and assessing dose distributions. The first step is to quantify the spatial relationships between the tumor and surrounding critical structures through features that account for distance, volume, overlap, location, shape and orientation. These features are used to identify database cases that are anatomically similar to the new patient. The dose profiles of these database cases can help clinicians to estimate an acceptable dose distribution for the new case, based on empirical evidence. Since database diversity is essential for good system performance, an infrastructure for multi-institutional collaboration was also conceptualized in order to pave the way for data sharing of protected health information.
November 2016Hyperandrogenism Accompanies Increased Intra-Abdominal Fat Storage in Normal Weight Polycystic Ovary Syndrome Women.
Dumesic DA, Akopians AL, Madrigal VK, Ramirez E, Margolis DJ, Sarma MK, Thomas AM, Grogan TR, Haykal R, Schooler TA, Okeya BL, Abbott DH, Chazenbalk GD.
CONTEXT: Normal weight polycystic ovary syndrome (PCOS) women may have altered adipose structure-function underlying metabolic dysfunction. OBJECTIVE: This study examines whether adipose structure-functional changes exist in normal weight PCOS women and correlate with hyperandrogenism and/or hyperinsulinemia. DESIGN: This is a prospective cohort study. SETTING: The setting was an academic medical center. PATIENTS: Six normal weight PCOS women and 14 age- and body mass index-matched normoandrogenic ovulatory (NL) women were included. INTERVENTION(S): All women underwent circulating hormone and metabolic measurements; frequently sampled intravenous glucose tolerance testing; total body dual-energy x-ray absorptiometry; abdominal magnetic resonance imaging; and SC abdominal fat biopsy.
November 2016Simulation, Phantom Validation, and Clinical Evaluation of Fast pH-weighted Molecular Imaging Using Amine Chemical Exchange Saturation Transfer Echo Planar Imaging (CEST-EPI) in Glioma at 3 T.
Harris RJ, Cloughesy TF, Liau LM, Nghiemphu PL, Lai A, Pope WB, Ellingson BM.
Acidity within the extracellular milieu is a hallmark of cancer. There is a current need for fast, high spatial resolution pH imaging techniques for clinical evaluation of cancers, including gliomas. Chemical exchange saturation transfer (CEST) MRI targeting fast-exchanging amine protons can be used to obtain high-resolution pH-weighted images, but conventional CEST acquisition strategies are slow. There is also a need for more accurate MR simulations to better understand the effects of amine CEST pulse sequence parameters on pH-weighted image contrast. In the current study we present a simulation of amine CEST contrast specific for a newly developed CEST echoplanar imaging (EPI) pulse sequence. The accuracy of the simulations was validated by comparing the exchange rates and Z-spectrum under a variety of conditions using physical phantoms of glutamine with different pH values. The effects of saturation pulse shapes, pulse durations, pulse train lengths, repetition times, and relaxation rates of bulk water and exchangeable amine protons on the CEST signal were explored for normal-appearing white matter (NAWM), glioma, and cerebrospinal fluid. Last, 18 patients with WHO II-IV gliomas were evaluated. Results showed that the Z-spectrum was highly dependent on saturation pulse shape, repetition time, saturation amplitude, magnetic field strength, and T2 within bulk water; however, the Z-spectrum was only minimally influenced by saturation pulse duration and the specific relaxation rates of amine protons. Results suggest that a Gaussian saturation pulse train consisting of 3 x 100 ms pulses using the minimum allowable repetition time is optimal for achieving over 90% available contrast across all tissues. Results also demonstrate that high saturation pulse amplitude and scanner field strength (>3 T) are necessary for adequate endogenous pH-weighted amine CEST contrast. pH-weighted amine CEST contrast increased with increasing tumor grade, with glioblastoma showing significantly higher contrast compared with WHO II or III gliomas.
November 2016Ectopic Pregnancy: A Trainee's Guide to Making the Right Call: Women's Imaging.
Histed SN, Deshmukh M, Masamed R, Jude CM, Mohammad S, Patel MK.
Ectopic pregnancy, an embryo implanted outside the normal intrauterine location, is the leading cause of first-trimester maternal mortality and hemorrhage. The reported prevalence is 2% of all pregnancies in the United States, which increases to 18% in patients with first-trimester bleeding. Risk factors include tubal or uterine surgery, pelvic inflammatory disease, current intrauterine device, endometriosis, and in vitro fertilization. Understanding the early normal pregnancy sequence is important to accurately interpret pelvic ultrasonographic (US) images and to prevent a false-positive diagnosis of ectopic pregnancy in a viable intrauterine pregnancy (IUP).
November 2016Medical Imaging Informatics.
Hsu W, El-Saden S, Taira RK.
Imaging is one of the most important sources of clinically observable evidence that provides broad coverage, can provide insight on low-level scale properties, is noninvasive, has few side effects, and can be performed frequently. Thus, imaging data provides a viable observable that can facilitate the instantiation of a theoretical understanding of a disease for a particular patient context by connecting imaging findings to other biologic parameters in the model (e.g., genetic, molecular, symptoms, and patient survival). These connections can help inform their possible states and/or provide further coherent evidence. The field of radiomics is particularly dedicated to this task and seeks to extract quantifiable measures wherever possible. Example properties of investigation include genotype characterization, histopathology parameters, metabolite concentrations, vascular proliferation, necrosis, cellularity, and oxygenation. Important issues within the field include: signal calibration, spatial calibration, preprocessing methods (e.g., noise suppression, motion correction, and field bias correction), segmentation of target anatomic/pathologic entities, extraction of computed features, and inferencing methods connecting imaging features to biological states.
November 2016Bidirectional Contrast Agent Leakage Correction of Dynamic Susceptibility Contrast (DSC)-MRI Improves Cerebral Blood volume Estimation and Survival Prediction in Recurrent Glioblastoma Treated with Bevacizumab.
Leu K, Boxerman JL, Lai A, Nghiemphu PL, Pope WB, Cloughesy TF, Ellingson BM.
PURPOSE: To evaluate a leakage correction algorithm for T1 and T2* artifacts arising from contrast agent extravasation in dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) that accounts for bidirectional contrast agent flux and compare relative cerebral blood volume (CBV) estimates and overall survival (OS) stratification from this model to those made with the unidirectional and uncorrected models in patients with recurrent glioblastoma (GBM). MATERIALS AND METHODS: We determined median rCBV within contrast-enhancing tumor before and after bevacizumab treatment in patients (75 scans on 1.5T, 19 scans on 3.0T) with recurrent GBM without leakage correction and with application of the unidirectional and bidirectional leakage correction algorithms to determine whether rCBV stratifies OS.
November 2016Synovial Tumors and Proliferative Diseases.
Levine BD, Motamedi K, Seeger LL.
The clinical diagnosis of synovial tumors and synovial proliferative processes is difficult, as symptoms and physical examination findings are often nonspecific. Advanced imaging modalities, such as MRI, high-resolution ultrasound, and computed tomography, can aid clinical decision-making by providing accurate diagnosis of such diseases in many cases. This article focuses on those specific imaging features of synovial tumors and proliferative processes that can provide accurate diagnosis and guide appropriate patient management.
November 2016Relationship of ACL Injury and Posterior Tibial Slope With Patient Age, Sex, and Race.
Waiwaiole A, Gurbani A, Motamedi K, Seeger L, Sim MS, Nwajuaku P, Hame SL.
BACKGROUND: Posterior tibial slope (PTS) has been proposed as a potential risk factor for anterior cruciate ligament (ACL) injury; however, studies that have examined this relationship have provided inconclusive and sometimes contradictory results. Further characterization of this relationship may enable the medical community to identify individuals at greater risk for ACL injury and possibly characterize an anatomic target during surgical reconstruction. PURPOSE: The primary goal was to investigate the relationship between PTS and ACL injury. The secondary goal was to determine whether there are any patient factors, such as age, race, or sex, that correlate with ACL injury and PTS. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: Medical records of 221 patients who underwent magnetic resonance imaging (MRI) of the knee between January 2003 and December 2009 were reviewed. Patients were separated into 2 groups: a study group of those subjects who had undergone surgery for ACL injury (n = 107) and a control group of patients diagnosed with patellofemoral syndrome (n = 114). Demographic data were collected, and MRI images from both groups were analyzed using imaging software to obtain medial and lateral tibial slope measurements. Data were then analyzed using analysis of variance (ANOVA) comparison and a multivariable regression model to determine which, if any, patient factors were related to probability of having an ACL injury.
November 2016Clear Cell Renal Cell Carcinoma: Identifying the Gain of Chromosome 20 on Multiphasic MDCT.
Young JR, Young JA, Margolis DJ, Sauk S, Pantuck AJ, Sayre J, Raman SS.
PURPOSE: To investigate whether multiphasic multidetector computed tomography (MDCT) enhancement can help identify the gain of chromosome 20 in clear cell renal cell carcinomas (RCCs), a rare prognostically significant cytogenetic abnormality. METHODS: With the Institutional Review Board approval, we queried our institution's pathology database to derive a cohort of 52 cases of clear cell RCC with preoperative four-phase renal mass protocol MDCT and karyotypes of the resected specimens during a 10-year period. Each lesion was evaluated for absolute and relative (compared to contralateral normal renal cortex) attenuations in each phase. Relative attenuation was calculated as [(lesion attenuation - cortex attenuation)/cortex attenuation] x 100. The absolute and relative attenuations were compared using t-tests.
October 2016Indeterminate Pulmonary Nodules: How to Minimize Harm.
Barjaktarevic I, Arenberg D, Grimes BS, Ruchalski K, Aberle DR.
Each year, more than 1 million persons worldwide are found to have a lung nodule that carries a risk of being malignant. In reality, the vast majority of lung nodules are benign, whether identified by screening or incidentally. The consequences of delaying or missing the diagnosis of lung cancer can be substantial, as can be the consequences of invasive procedures on patients with benign lung nodules. The challenge for the clinician caring for these patients is to differentiate between benign and malignant nodules with the least harm possible. In this review, we will discuss management strategies of the indeterminate pulmonary nodule and will review recent advances and harm-reduction strategies.
October 2016ACRIN 6684: Assessment of Tumor Hypoxia in Newly Diagnosed Glioblastoma Using 18F-FMISO PET and MRI.
Gerstner ER, Zhang Z, Fink JR, Muzi M, Hanna L, Greco E, Prah M, Schmainda KM, Mintz A, Kostakoglu L, Eikman EA, Ellingson BM, Ratai EM, Sorensen AG, Barboriak DP, Mankoff DA; ACRIN 6684 Trial Group..
PURPOSE: Structural and functional alterations in tumor vasculature are thought to contribute to tumor hypoxia which is a primary driver of malignancy through its negative impact on the efficacy of radiation, immune surveillance, apoptosis, genomic stability, and accelerated angiogenesis. We performed a prospective, multicenter study to test the hypothesis that abnormal tumor vasculature and hypoxia, as measured with MRI and PET, will negatively impact survival in patients with newly diagnosed glioblastoma. EXPERIMENTAL DESIGN: Prior to the start of chemoradiation, patients with glioblastoma underwent MRI scans that included dynamic contrast enhanced and dynamic susceptibility contrast perfusion sequences to quantitate tumor cerebral blood volume/flow (CBV/CBF) and vascular permeability (ktrans) as well as 18F-Fluoromisonidazole (18F-FMISO) PET to quantitate tumor hypoxia. ROC analysis and Cox regression models were used to determine the association of imaging variables with progression-free and overall survival.
October 2016Inpatient Cost Assessment of Transjugular Intrahepatic Portosystemic Shunt in the USA from 2001 to 2012.
Kuei A, Lee EW, Saab S, Busuttil RW, Durazo F, Han SH, ElKabany M, McWilliams JP, Kee ST.
BACKGROUND: Despite widespread use of transjugular intrahepatic portosystemic shunt (TIPS) for treatment of portal hypertension, a paucity of nationwide data exists on predictors of the economic impact related to TIPS. AIMS: Using the National Inpatient Sample (NIS) database from 2001 to 2012, we aimed to evaluate factors contributing to hospital cost of patients admitted to US hospitals for TIPS. METHODS: Using the NIS, we identified a discharge-weighted national estimate of 61,004 TIPS procedures from 2001 to 2012. Through independent sample analysis, we determined profile factors related to increases in hospital costs.
October 2016MR Imaging and US of the Wrist Tendons.
Plotkin B, Sampath SC, Sampath SC, Motamedi K.
The tendons of the wrist are commonly symptomatic. They can be injured, infected, or inflamed. Magnetic resonance imaging and ultrasonography are useful tools for evaluating the wrist. Pathologic conditions of the wrist tendons include de Quervain tenosynovitis, extensor carpi ulnaris tendinopathy, rheumatoid tenosynovitis, infectious synovitis, tendon tears, hydroxyapatite deposition disease, intersection syndrome, tenosynovial giant cell tumor, and fibroma of the tendon sheath. In this article, we review the normal appearance of the wrist tendons, discuss relevant anatomy, and give an overview of common pathologic conditions affecting the wrist tendons. Online supplemental material is available for this article.
October 2016SPIROMICS Protocol for Multicenter Quantitative Computed Tomography to Phenotype the Lungs.
Sieren JP, Newell JD Jr, Barr RG, Bleecker ER, Burnette N, Carretta EE, Couper D, Goldin J, Guo J, Han MK, Hansel NN, Kanner RE, Kazerooni EA, Martinez FJ, Rennard S, Woodruff PG, Hoffman EA; SPIROMICS Research Group.
Multidetector row computed tomography (MDCT) is increasingly taking a central role in identifying subphenotypes within chronic obstructive pulmonary disease (COPD), asthma, and other lung-related disease populations, allowing for the quantification of the amount and distribution of altered parenchyma along with the characterization of airway and vascular anatomy. The embedding of quantitative CT (QCT) into a multicenter trial with a variety of scanner makes and models along with the variety of pressures within a clinical radiology setting has proven challenging, especially in the context of a longitudinal study. SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study), sponsored by the National Institutes of Health, has established a QCT lung assessment system (QCT-LAS), which includes scanner-specific imaging protocols for lung assessment at total lung capacity and residual volume. Also included are monthly scanning of a standardized test object and web-based tools for subject registration, protocol assignment, and data transmission coupled with automated image interrogation to assure protocol adherence. The SPIROMICS QCT-LAS has been adopted and contributed to by a growing number of other multicenter studies in which imaging is embedded. The key components of the SPIROMICS QCT-LAS along with evidence of implementation success are described herein. While imaging technologies continue to evolve, the required components of a QCT-LAS provide the framework for future studies, and the QCT results emanating from SPIROMICS and the growing number of other studies using the SPIROMICS QCT-LAS will provide a shared resource of image-derived pulmonary metrics.
October 2016Free-breathing Variable Flip Angle Balanced SSFP Cardiac Cine Imaging with Reduced SAR at 3T.
Srinivasan S, Kroeker RM, Gabriel S, Plotnik A, Godinez SR, Hu P, Halnon N, Finn JP, Ennis DB.
PURPOSE: To develop a free-breathing variable flip angle (VFA) balanced steady-state free precession (bSSFP) cardiac cine imaging technique with reduced specific absorption rate (SAR) at 3 Tesla. METHODS: Free-breathing VFA (FB-VFA) images in the short-axis and four-chamber views were acquired using an optimal VFA scheme, then compared with conventional breath-hold constant flip angle (BH-CFA) acquisitions. Two cardiac MRI experts used a 5-point scale to score images from healthy subjects (N = 10). The left ventricular ejection fraction, end diastolic volume (LVEDV), end systolic volume, stroke volume (LVSV), and end diastolic myocardial mass (LVEDM) were determined by manual contour analysis for BH-CFA and FB-VFA. A pilot evaluation of FB-VFA was performed in one patient with Duchenne muscular dystrophy.
October 2016Does Hepatobiliary Phase Sequence Qualitatively Outperform Unenhanced T1-weighted Imaging in Assessment of the Ablation Margin 24 Hours after Thermal Ablation of Hepatocellular Carcinomas?
Takeyama N, Vidhyarkorn S, Chung DJ, Siripongsakun S, Kim HJ, Lu DS, Raman SS.
PURPOSE: To retrospectively determine whether hepatobiliary phase (HBP) sequence outperforms unenhanced T1-weighted imaging (uT1wI) in distinguishing the ablation margin (AM) from hepatocellular carcinoma (HCC) 24 h after thermoablation. MATERIAL AND METHODS: Ninety-one patients [mean age, 65.7 years; 68 M/23F] with 138 HCCs (>6 months follow-up) underwent pre- and postablation gadoxetate disodium-enhanced MRI. AM showed a hyperintense middle zone (MZ) surrounding central hypo- or hyperintense HCCs on uT1wI, and an intermediate-intense MZ encompassing central hypo- or hyperintense HCCs during HBP. The visible AM was defined as persistent MZ around HCCs, which were demarcated from MZ, or peripherally band encompassing MZ, which were not demarcated from HCC. The indefinite AM was defined as no demarcating HCCs from MZ. The ability to distinguish AM from HCC was classified as visible or indefinite on axial (ax)-uT1wI, ax-HBP, coronal (cor)-HBP, and combined all images. To investigate the AM visibility during HBP, significance of differences upon comparison of ax-uT1wI with combined images was analyzed. Preablation liver-tumor contrast ratio (LTCR)) on ax-uT1wI and ax-HBP sequence is compared between the visible and indefinite AM.
October 2016Scar Voltage Threshold Determination Using Ex Vivo Magnetic Resonance Imaging Integration in a Porcine Infarct Model: Influence of Interelectrode Distances and Three-dimensional Spatial Effects of Scar.
Tung R, Kim S, Yagishita D, Vaseghi M, Ennis DB, Ouadah S, Ajijola OA, Bradfield JS, Mahapatra S,Finn P, Shivkumar K.
BACKGROUND: Studies analyzing optimal voltage thresholds for scar detection with electroanatomic mapping frequently lack a gold standard for comparison. OBJECTIVE: The purpose of this study was to use a porcine infarct model with ex vivo magnetic resonance imaging (MRI) integration to characterize the relationship between interelectrode spacing and bipolar voltage thresholds and examine the influence of 3-dimensional scar on unipolar voltages. METHODS: Thirty-two combined endocardial-epicardial electroanatomic maps were created in 8 postinfarct porcine subjects (bipolar 2-mm, 5-mm, and 8-mm interelectrode spacing and unipolar) for comparison with ex vivo MRI. Two thresholds were compared: (1) 95% normal distribution and (2) best fit to MRI. Direct electrogram analysis was performed in regions across from MRI-defined scar and adjacent to scar border zone.
September 2016Defining New Metrics in Microwave Ablation of Pulmonary Tumors: Ablation Work and Ablation Resistance Score.
Al-Hakim RA, Abtin FG, Genshaft SJ, Kutay E, Suh RD.
PURPOSE: To investigate pulmonary microwave ablation metrics including ablation work, ablation resistance score, and involution. MATERIALS AND METHODS: Retrospective review was performed of 98 pulmonary tumor ablations using the NeuWave Certus Microwave Ablation System (NeuWave Medical, Madison, Wisconsin) in 71 patients (32 men and 39 women; mean age, 64.7 y ± 11.5). Ablation work was defined as sum of (power) * (time) * (number of antennas) for all phases during an ablation procedure. Ablation zone was measured on CT at 3 time points: after procedure, 1-3 months (mean 47 d), and 3-12 months (mean 292 d). Ablation zones were scored based on location for pulmonary lobe (upper = 1, middle/lingula = 2, lower = 3) and region (peripheral = 1, parenchymal = 2, central = 3), and the 2 were summed for ablation resistance score.
September 2016Enhancements in Hepatobiliary Imaging: the Spectrum of Gadolinium-ethoxybenzyl Diethylenetriaminepentaacetic Acid Usages in Hepatobiliary Magnetic Resonance Imaging.
Channual S, Pahwa A, Lu DS, Raman SS.
Gadolinium-ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) is a unique hepatocyte-specific contrast agent approved for clinical use in the United States in 2008. Gd-EOB-DTPA-enhanced MR has shown to improve detection and characterization of hepatic lesions. Gd-EOB-DTPA is now being routinely used in daily clinical practice worldwide. Therefore, it is important for radiologists to be familiar with the potential uses and pitfalls of Gd-EOB-DTPA, which extends beyond the assessment of focal hepatic lesions. The purpose of this article is to review the various usages of Gd-EOB-DTPA in hepatobiliary MR imaging.
September 2016Managing Scale and Innovation in Health IT.
Enzmann DR, Pfeffer M.
Given the high-intensity interaction between radiology and IT, radiology leadership should understand IT's new, somewhat conflicting, dual roles. Managing large-scale and small-scale projects concurrently has become an important challenge for leaders of health IT (HIT). Historical parallels of this challenge can be drawn from transportation and communication systems, in which a large-scale mind-set is needed to build the initial network, whereas a small-scale mind-set is more useful to develop the content that will traverse this network. Innovation and creativity is a cornerstone of content small-scale thinking, and in HIT, that is what is needed to extract the value from it. However, unlike the early historical transportation and communication examples, the time between the development of the infrastructure and the follow-on, value-rich content is shortened greatly because it has become nearly simultaneous in HIT. Weaving the ability to concomitantly manage both large- and small-scale projects into the fabric of the organizational HIT culture will be critical for its success.
September 2016A 3-dimensional DTI MRI-based Model of GBM Growth and Response to Radiation Therapy.
Hathout L, Patel V, Wen P.
Glioblastoma (GBM) is both the most common and the most aggressive intra-axial brain tumor, with a notoriously poor prognosis. To improve this prognosis, it is necessary to understand the dynamics of GBM growth, response to treatment and recurrence. The present study presents a mathematical diffusion-proliferation model of GBM growth and response to radiation therapy based on diffusion tensor (DTI) MRI imaging. This represents an important advance because it allows 3-dimensional tumor modeling in the anatomical context of the brain. Specifically, tumor infiltration is guided by the direction of the white matter tracts along which glioma cells infiltrate. This provides the potential to model different tumor growth patterns based on location within the brain, and to simulate the tumor's response to different radiation therapy regimens. Tumor infiltration across the corpus callosum is simulated in biologically accurate time frames. The response to radiation therapy, including changes in cell density gradients and how these compare across different radiation fractionation protocols, can be rendered. Also, the model can estimate the amount of subthreshold tumor which has extended beyond the visible MR imaging margins. When combined with the ability of being able to estimate the biological parameters of invasiveness and proliferation of a particular GBM from serial MRI scans, it is shown that the model has potential to simulate realistic tumor growth, response and recurrence patterns in individual patients. To the best of our knowledge, this is the first presentation of a DTI-based GBM growth and radiation therapy treatment model.
September 2016Truncating Mutations in APP Cause a Distinct Neurological Phenotype.
Klein S, Goldman A, Lee H, Ghahremani S, Bhakta V; UCLA Clinical Genomics Center, Nelson SF, Martinez-Agosto JA.
Dominant missense mutations in the amyloid β (Aβ) precursor protein (APP) gene have been implicated in early onset Alzheimer disease. These mutations alter protein structure to favor the pathologic production of Aβ. We report that homozygous nonsense mutations in APP are associated with decreased somatic growth, microcephaly, hypotonia, developmental delay, thinning of the corpus callosum, and seizures. We compare the phenotype of this case to those reported in mouse models and demonstrate multiple similarities, strengthening the role of amyloid precursor protein in normal brain function and development.
September 2016Prediction of Lung Cancer Incidence on the Low-dose Computed Tomography Arm of the National Lung Screening Trial: A Dynamic Bayesian Network.
Petousis P, Han SX, Aberle D, Bui AA.
INTRODUCTION: Identifying high-risk lung cancer individuals at an early disease stage is the most effective way of improving survival. The landmark National Lung Screening Trial (NLST) demonstrated the utility of low-dose computed tomography (LDCT) imaging to reduce mortality (relative to X-ray screening). As a result of the NLST and other studies, imaging-based lung cancer screening programs are now being implemented. However, LDCT interpretation results in a high number of false positives. A set of dynamic Bayesian networks (DBN) were designed and evaluated to provide insight into how longitudinal data can be used to help inform lung cancer screening decisions. METHODS: The LDCT arm of the NLST dataset was used to build and explore five DBNs for high-risk individuals. Three of these DBNs were built using a backward construction process, and two using structure learning methods. All models employ demographics, smoking status, cancer history, family lung cancer history, exposure risk factors, comorbidities related to lung cancer, and LDCT screening outcome information. Given the uncertainty arising from lung cancer screening, a cancer state-space model based on lung cancer staging was utilized to characterize the cancer status of an individual over time. The models were evaluated on balanced training and test sets of cancer and non-cancer cases to deal with data imbalance and overfitting.
September 2016Interobserver Reproducibility of the PI-RADS Version 2 Lexicon: A Multicenter Study of Six Experienced Prostate Radiologists.
Rosenkrantz AB, Ginocchio LA, Cornfeld D, Froemming AT, Gupta RT, Turkbey B, Westphalen AC, Babb JS, Margolis DJ.
Purpose To determine the interobserver reproducibility of the Prostate Imaging Reporting and Data System (PI-RADS) version 2 lexicon. Materials and Methods This retrospective HIPAA-compliant study was institutional review board-approved. Six radiologists from six separate institutions, all experienced in prostate magnetic resonance (MR) imaging, assessed prostate MR imaging examinations performed at a single center by using the PI-RADS lexicon. Readers were provided screen captures that denoted the location of one specific lesion per case. Analysis entailed two sessions (40 and 80 examinations per session) and an intersession training period for individualized feedback and group discussion. Percent agreement (fraction of pairwise reader combinations with concordant readings) was compared between sessions. k coefficients were computed. Results No substantial difference in interobserver agreement was observed between sessions, and the sessions were subsequently pooled. Agreement for PI-RADS score of 4 or greater was 0.593 in peripheral zone (PZ) and 0.509 in transition zone (TZ). In PZ, reproducibility was moderate to substantial for features related to diffusion-weighted imaging (k = 0.535-0.619); fair to moderate for features related to dynamic contrast material-enhanced (DCE) imaging (k = 0.266-0.439); and fair for definite extraprostatic extension on T2-weighted images (k = 0.289). In TZ, reproducibility for features related to lesion texture and margins on T2-weighted images ranged from 0.136 (moderately hypointense) to 0.529 (encapsulation). Among 63 lesions that underwent targeted biopsy, classification as PI-RADS score of 4 or greater by a majority of readers yielded tumor with a Gleason score of 3+4 or greater in 45.9% (17 of 37), without missing any tumor with a Gleason score of 3+4 or greater. Conclusion Experienced radiologists achieved moderate reproducibility for PI-RADS version 2, and neither required nor benefitted from a training session. Agreement tended to be better in PZ than TZ, although was weak for DCE in PZ. The findings may help guide future PI-RADS lexicon updates.
September 2016Mycophenolate Mofetil Versus Oral Cyclophosphamide in Scleroderma-related Interstitial Lung Disease (SLS II): a Randomised Controlled, Double-blind, Parallel Group Trial.
Tashkin DP, Roth MD, Clements PJ, Furst DE, Khanna D, Kleerup EC, Goldin J, Arriola E, Volkmann ER, Kafaja S, Silver R, Steen V, Strange C, Wise R, Wigley F, Mayes M, Riley DJ, Hussain S, Assassi S, Hsu VM, Patel B, Phillips K, Martinez F, Golden J, Connolly MK, Varga J, Dematte J, Hinchcliff ME, Fischer A, Swigris J, Meehan R, Theodore A, Simms R, Volkov S, Schraufnagel DE, Scholand MB, Frech T, Molitor JA, Highland K, Read CA, Fritzler MJ, Kim GH, Tseng CH, Elashoff RM; Sclerodema Lung Study II Investigators.
BACKGROUND: 12 months of oral cyclophosphamide has been shown to alter the progression of scleroderma-related interstitial lung disease when compared with placebo. However, toxicity was a concern and without continued treatment the efficacy disappeared by 24 months. We hypothesised that a 2 year course of mycophenolate mofetil would be safer, better tolerated, and produce longer lasting improvements than cyclophosphamide. METHODS: This randomised, double-blind, parallel group trial enrolled patients from 14 US medical centres with scleroderma-related interstitial lung disease meeting defined dyspnoea, pulmonary function, and high-resolution CT (HRCT) criteria. The data coordinating centre at the University of California, Los Angeles (UCLA, CA, USA), randomly assigned patients using a double-blind, double-dummy, centre-blocked design to receive either mycophenolate mofetil (target dose 1500 mg twice daily) for 24 months or oral cyclophosphamide (target dose 2·0 mg/kg per day) for 12 months followed by placebo for 12 months. Drugs were given in matching 250 mg gel capsules. The primary endpoint, change in forced vital capacity as a percentage of the predicted normal value (FVC %) over the course of 24 months, was assessed in a modified intention-to-treat analysis using an inferential joint model combining a mixed-effects model for longitudinal outcomes and a survival model to handle non-ignorable missing data. The study was registered with ClinicalTrials.gov, number NCT00883129.
September 2016Effect of Topical Intranasal Therapy on Epistaxis Frequency in Patients With Hereditary Hemorrhagic Telangiectasia: A Randomized Clinical Trial.
Whitehead KJ, Sautter NB, McWilliams JP, Chakinala MM, Merlo CA, Johnson MH, James M, Everett EM, Clancy MS, Faughnan ME, Oh SP, Olitsky SE, Pyeritz RE, Gossage JR.
IMPORTANCE: Epistaxis is a major factor negatively affecting quality of life in patients with hereditary hemorrhagic telangiectasia (HHT; also known as Osler-Weber-Rendu disease). Optimal treatment for HHT-related epistaxis is uncertain. OBJECTIVE: To determine whether topical therapy with any of 3 drugs with differing mechanisms of action is effective in reducing HHT-related epistaxis. DESIGN, SETTING, AND PARTICIPANTS: The North American Study of Epistaxis in HHT was a double-blind, placebo-controlled randomized clinical trial performed at 6 HHT centers of excellence. From August 2011 through March 2014, there were 121 adult patients who met the clinical criteria for HHT and had experienced HHT-related epistaxis with an Epistaxis Severity Score of at least 3.0. Follow-up was completed in September 2014. INTERVENTIONS: Patients received twice-daily nose sprays for 12 weeks with either bevacizumab 1% (4 mg/d), estriol 0.1% (0.4 mg/d), tranexamic acid 10% (40 mg/d), or placebo (0.9% saline). MAIN OUTCOMES AND MEASURES: The primary outcome was median weekly epistaxis frequency during weeks 5 through 12. Secondary outcomes included median duration of epistaxis during weeks 5 through 12, Epistaxis Severity Score, level of hemoglobin, level of ferritin, need for transfusion, emergency department visits, and treatment failure.
September 2016Mutations Associated with Acquired Resistance to PD-1 Blockade in Melanoma.
Zaretsky JM, Garcia-Diaz A, Shin DS, Escuin-Ordinas H, Hugo W, Hu-Lieskovan S, Torrejon DY, Abril-Rodriguez G, Sandoval S, Barthly L, Saco J, Homet Moreno B, Mezzadra R, Chmielowski B,Ruchalski K, Shintaku IP, Sanchez PJ, Puig-Saus C, Cherry G, Seja E, Kong X, Pang J, Berent-Maoz B, Comin-Anduix B, Graeber TG, Tumeh PC, Schumacher TN, Lo RS, Ribas A.
BACKGROUND: Approximately 75% of objective responses to anti-programmed death 1 (PD-1) therapy in patients with melanoma are durable, lasting for years, but delayed relapses have been noted long after initial objective tumor regression despite continuous therapy. Mechanisms of immune escape in this context are unknown. METHODS: We analyzed biopsy samples from paired baseline and relapsing lesions in four patients with metastatic melanoma who had had an initial objective tumor regression in response to anti-PD-1 therapy (pembrolizumab) followed by disease progression months to years later.
August 2016Algorithm Variability in the Estimation of Lung Nodule Volume From Phantom CT Scans: Results of the QIBA 3A Public Challenge.
Athelogou M, Kim HJ, Dima A, Obuchowski N, Peskin A, Gavrielides MA, Petrick N, Saiprasad G, Colditz Colditz D, Beaumont H, Oubel E, Tan Y, Zhao B, Kuhnigk JM, Moltz JH, Orieux G, Gillies RJ, Gu Y, Mantri N, Goldmacher G, Zhang L, Vega E, Bloom M, Jarecha R, Soza G, Tietjen C, Takeguchi T, Yamagata H, Peterson S, Masoud O, Buckler AJ.
RATIONALE AND OBJECTIVES: Quantifying changes in lung tumor volume is important for diagnosis, therapy planning, and evaluation of response to therapy. The aim of this study was to assess the performance of multiple algorithms on a reference data set. The study was organized by the Quantitative Imaging Biomarker Alliance (QIBA). MATERIALS AND METHODS: The study was organized as a public challenge. Computed tomography scans of synthetic lung tumors in an anthropomorphic phantom were acquired by the Food and Drug Administration. Tumors varied in size, shape, and radiodensity. Participants applied their own semi-automated volume estimation algorithms that either did not allow or allowed post-segmentation correction (type 1 or 2, respectively). Statistical analysis of accuracy (percent bias) and precision (repeatability and reproducibility) was conducted across algorithms, as well as across nodule characteristics, slice thickness, and algorithm type.
August 2016Transcriptome Profiling Reveals Novel Gene Expression Signatures and Regulating Transcription Factors of TGFβ-induced Epithelial-to-mesenchymal Transition.
Du L, Yamamoto S, Burnette BL, Huang D, Gao K, Jamshidi N, Kuo MD.
Dysregulated epithelial to mesenchymal transition (EMT) in cancer cells endows invasive and metastatic properties upon cancer cells that favor successful colonization of distal target organs and therefore play a critical role in transforming early-stage carcinomas into invasive malignancies. EMT has also been associated with tumor recurrence and drug resistance and cancer stem cell initiation. Therefore, better understanding of the mechanisms behind EMT could ultimately contribute to the development of novel prognostic approaches and individualized therapies that specifically target EMT processes. As an effort to characterize the central transcriptome changes during EMT, we have developed a Transforming growth factor (TGF)-beta-based in vitro EMT model and used it to profile EMT-related gene transcriptional changes in two different cell lines, a non-small cell lung cancer cell line H358, and a breast cell line MCF10a. After 7 days of TGF-beta/Oncostatin M (OSM) treatment, changes in cell morphology to a mesenchymal phenotype were observed as well as concordant EMT-associated changes in mRNA and protein expression. Further, increased motility was noted and flow cytometry confirmed enrichment in cancer stem cell-like populations. Microarray-based differential expression analysis identified an EMT-associated gene expression signature which was confirmed by RT-qPCR and which significantly overlapped with a previously published EMT core signature. Finally, two novel EMT-regulating transcription factors, IRF5 and LMCD1, were identified and independently validated.
August 2016Cardiovascular MRI with Ferumoxytol.
Finn JP, Nguyen KL, Han F, Zhou Z, Salusky I, Ayad I, Hu P.
The practice of contrast-enhanced magnetic resonance angiography (CEMRA) has changed significantly in the span of a decade. Concerns regarding gadolinium (Gd)-associated nephrogenic systemic fibrosis in those with severely impaired renal function spurred developments in low-dose CEMRA and non-contrast MRA as well as efforts to seek alternative MR contrast agents. Originally developed for MR imaging use, ferumoxytol (an ultra-small superparamagnetic iron oxide nanoparticle), is currently approved by the US Food and Drug Administration for the treatment of iron deficiency anaemia in adults with renal disease. Since its clinical availability in 2009, there has been rising interest in the scientific and clinical use of ferumoxytol as an MR contrast agent. The unique physicochemical and pharmacokinetic properties of ferumoxytol, including its long intravascular half-life and high r1 relaxivity, support a spectrum of MRI applications beyond the scope of Gd-based contrast agents. Moreover, whereas Gd is not found in biological systems, iron is essential for normal metabolism, and nutritional iron deficiency poses major public health challenges worldwide. Once the carbohydrate shell of ferumoxytol is degraded, the elemental iron at its core is incorporated into the reticuloendothelial system. These considerations position ferumoxytol as a potential game changer in the field of CEMRA and MRI. In this paper, we aim to summarise our experience with the cardiovascular applications of ferumoxytol and provide a brief synopsis of ongoing investigations on ferumoxytol-enhanced MR applications.
August 2016Modeling the Efficacy of the Extent of Surgical Resection in the Setting of Radiation Therapy for Glioblastoma.
Hathout L, Ellingson B, Pope W.
Standard therapy for glioblastoma (GBM) includes maximal surgical resection and radiation therapy. While it is established that radiation therapy provides the greatest survival benefit of standard treatment modalities, the impact of the extent of surgical resection (EOR) on patient outcome remains highly controversial. While some studies describe no correlation between EOR and patient survival even up to total resection, others propose either qualitative (partial versus subtotal versus complete resection) or quantitative EOR thresholds, below which there is no correlation with survival. This work uses a mathematical model in the form of a reaction-diffusion partial differential equation to simulate tumor growth and treatment with radiation therapy and surgical resection based on tumor-specific rates of diffusion and proliferation. Simulation of 36 tumors across a wide spectrum of diffusion and proliferation rates suggests that while partial or subtotal resections generally do not provide a survival advantage, complete resection significantly improves patient outcomes. Furthermore, our model predicts a tumor-specific quantitative threshold below which EOR has no effect on patient survival and demonstrates that this threshold increases with tumor aggressiveness, particularly with the rate of proliferation. Thus, this model may serve as an aid for determining both when surgical resection is indicated as well as the surgical margins necessary to provide clinically significant improvements in patient survival. In addition, by assigning relative benefits to radiation and surgical resection based on tumor invasiveness and proliferation, this model confirms that (with the exception of the least aggressive tumors) the survival benefit of radiation therapy exceeds that of surgical resection.
August 2016The Radiogenomic Risk Score Stratifies Outcomes in a Renal Cell Cancer Phase 2 Clinical Trial.
Jamshidi N, Jonasch E, Zapala M, Korn RL, Brooks JD, Ljungberg B, Kuo MD.
OBJECTIVES: To characterize a radiogenomic risk score (RRS), a previously defined biomarker, and to evaluate its potential for stratifying radiological progression-free survival (rPFS) in patients with metastatic renal cell carcinoma (mRCC) undergoing pre-surgical treatment with bevacizumab. METHODOLOGY: In this IRB-approved study, prospective imaging analysis of the RRS was performed on phase II clinical trial data of mRCC patients (n = 41) evaluating whether patient stratification according to the RRS resulted in groups more or less likely to have a rPFS to pre-surgical bevacizumab prior to cytoreductive nephrectomy. Survival times of RRS subgroups were analyzed using Kaplan-Meier survival analysis.
August 2016Magnetic Resonance Arthrography and the Prevalence of Acetabular Labral Tears in Patients 50 Years of Age and Older.
Jayakar R, Merz A, Plotkin B, Wang D, Seeger L, Hame SL.
OBJECTIVE: Arthroscopy for acetabular labral tears has minimal impact on pain and function in older patients, especially in the setting of concomitant osteoarthritis. Still, many physicians seek this diagnosis with MR arthrography. Our purpose is to assess the frequency of acetabular labral tears in older patients with hip pain and correlate likelihood of labral pathology with severity of osteoarthritis as visualized on conventional radiograph. MATERIALS AND METHODS: From 2004 to 2013, 208 hip MRI arthrograms and corresponding radiographs on patients aged 50 years and older were identified. Age, gender, grade and location of labral tear, alpha angle, Tönnis grade, and joint space width were documented. Labral tears and alpha angle were identified and measured on MR arthrogram. Tönnis grade and joint space width were measured on radiographs.
August 2016Improved Leakage Correction for Single-Echo Dynamic Susceptibility Contrast Perfusion MRI Estimates of Relative Cerebral Blood Volume in High-Grade Gliomas by Accounting for Bidirectional Contrast Agent Exchange.
Leu K, Boxerman JL, Cloughesy TF, Lai A, Nghiemphu PL, Liau LM, Pope WB, Ellingson BM.
BACKGROUND AND PURPOSE: Contrast agent extravasation through a disrupted blood-brain barrier potentiates inaccurate DSC MR imaging estimation of relative CBV. We explored whether incorporation of an interstitial washout rate in a leakage-correction model for single-echo, gradient-echo DSC MR imaging improves relative CBV estimates in high-grade gliomas. MATERIALS AND METHODS: We modified the traditional model-based postprocessing leakage-correction algorithm, assuming unidirectional contrast agent extravasation (Boxerman-Weisskoff model) to account for bidirectional contrast agent exchange between intra- and extravascular spaces (bidirectional model). For both models, we compared the goodness of fit with the parent leakage-contaminated relaxation rate curves by using the Akaike Information Criterion and the difference between modeled interstitial relaxation rate curves and dynamic contrast-enhanced MR imaging by using Euclidean distance in 21 patients with glioblastoma multiforme.
August 2016Contrast-enhanced Magnetic Resonance Venography in Pediatric Patients with Chronic Kidney Disease: Initial Experience with Ferumoxytol.
Luhar A, Khan S, Finn JP, Ghahremani S, Griggs R, Zaritsky J, Salusky I, Hall TR.
Ferumoxytol is an ultra-small superparamagnetic iron oxide (USPIO) particle that is FDA-approved for parenteral treatment of iron deficiency anemia in adults with chronic kidney disease. Because of the association between gadolinium-based contrast agents and nephrogenic systemic fibrosis in patients with severe chronic kidney disease, we sought to evaluate the diagnostic role of ferumoxytol-enhanced MR venography in children with chronic kidney disease. Twenty children underwent 22 high-resolution ferumoxytol-enhanced MR venography examinations at 3.0 T. High-resolution 3-D contrast-enhanced imaging was performed at a minimum of 3 time points following injection of ferumoxytol at a total dose of 4 mg/kg. Two blinded pediatric radiologists independently scored six named veins on ferumoxytol-enhanced MR venography examinations according to a three-point subjective score, where a score ≥ 2 was considered diagnostic. Additionally, all relevant venous structures in the included field of view were analyzed for occlusive or non-occlusive thrombosis, compression and presence of collaterals. All patients underwent ferumoxytol-enhanced MR venography successfully and without adverse event. The overall scores of the reviewing radiologists for all venous structures were 2.7-2.9. In all cases, the reviewers were confident basing their diagnoses on the ferumoxytol-enhanced MR venography findings. In 12 of 22 examinations, findings on follow-up imaging or invasive procedures were available to correlate with the findings on ferumoxytol-enhanced MR venography. There was complete concordance between the findings from follow-up imaging and invasive procedures with findings from ferumoxytol-enhanced MR venography. Ferumoxytol holds promise as a powerful alternative to gadolinium-based contrast agents for reliable, high-resolution MR venography in children with chronic kidney disease.
August 2016Obstructive Sleep Apnea is Associated with Low GABA and High Glutamate in the Insular Cortex.
Macey PM, Sarma MK, Nagarajan R, Aysola R, Siegel JM, Harper RM, Thomas MA.
The insular cortex is injured in obstructive sleep apnea (OSA) and responds inappropriately to autonomic challenges, suggesting neural reorganization. The objective of this study was to assess whether the neural changes might result from γ-aminobutyric acid (GABA) and glutamate alterations. We studied 14 OSA patients [mean age ± standard deviation (SD): 47.5 ± 10.5 years; nine male; apnea-hypopnea index (AHI): 29.5 ± 15.6 events h(-1) ] and 22 healthy participants (47.5 ± 10.1 years; 11 male), using magnetic resonance spectroscopy to detect GABA and glutamate levels in insular cortices. We localized the cortices with anatomical scans, and measured neurochemical levels from anterior to mid-regions. Left and right anterior insular cortices showed lower GABA and higher glutamate in OSA versus healthy subjects [GABA left: OSA n = 6: 0.36 ± 0.10 (mean ± SD), healthy n = 5: 0.62 ± 0.18; P < 0.05), right: OSA n = 11: 0.27 ± 0.09, healthy n = 14: 0.45 ± 0.16; P < 0.05; glutamate left: OSA n = 6: 1.61 ± 0.32, healthy n = 8: 0.94 ± 0.34; P < 0.05, right: OSA n = 14: 1.26 ± 0.28, healthy n = 19: 1.02 ± 0.28; P < 0.05]. GABA and glutamate levels were correlated only within the healthy group in the left insula (r: -0.9, P < 0.05). The altered anterior insular levels of GABA and glutamate may modify integration and projections to autonomic areas, contributing to the impaired cardiovascular regulation in OSA.
August 2016Intestinal Perforation Following Ileoscopy Through a Prolapsed Stoma in an Pediatric Intestinal Transplant Recipient With an Unrecognized Parastomal Hernia.
Mehrotra P, Yeh J, Hall TR, Agopian VG, Farmer DG, Marcus EA, Venick RS, Wozniak LJ.
Ileoscopy with mucosal biopsy is fundamental in the management and surveillance of inflammatory bowel disease patients and intestinal transplant recipients. There is a paucity of data describing the risks of ileoscopy in the presence of a prolapsed stoma. Parastomal hernias are frequently associated with prolapsed stomas. We report the first case of perforation during ileoscopy in the setting of a prolapsed stoma and unrecognized parastomal hernia. Recognition of parastomal hernia associated with stoma prolapse is of paramount importance in patients undergoing ileoscopy as it may increase the risk of perforation.
August 2016Cardiac MRI: a Translational Imaging Tool for Characterizing Anthracycline-Induced Myocardial Remodeling.
Nguyen KL, Hu P, Ennis DB, Shao J, Pham KA, Chen JJ.
Cardiovascular side effects of cancer therapeutics are the leading causes of morbidity and mortality in cancer survivors. Anthracyclines (AC) serve as the backbone of many anti-cancer treatment strategies, but dose-dependent myocardial injury limits their use. Cumulative AC exposure can disrupt the dynamic equilibrium of the myocardial microarchitecture while repeated injury and repair leads to myocyte loss, interstitial myocardial fibrosis, and impaired contractility. Although children are assumed to have greater myocardial plasticity, AC exposure at a younger age portends worse prognosis. In older patients, there is lower overall survival once they develop cardiovascular disease. Because aberrations in the myocardial architecture predispose the heart to a decline in function, early detection with sensitive imaging tools is crucial and the implications for resource utilization are substantial. As a comprehensive imaging modality, cardiac magnetic resonance (CMR) imaging is able to go beyond quantification of ejection fraction and myocardial deformation to characterize adaptive microstructural and microvascular changes that are important to myocardial tissue health. Herein, we describe CMR as an established translational imaging tool that can be used clinically to characterize AC-associated myocardial remodeling.
August 2016Cingulate and Thalamic Metabolites in Obsessive-compulsive Disorder.
O'Neill J, Lai TM, Sheen C, Salgari GC, Ly R, Armstrong C, Chang S, Levitt JG, Salamon N, Alger JR, Feusner JD.
Focal brain metabolic effects detected by proton magnetic resonance spectroscopy (MRS) in obsessive-compulsive disorder (OCD) represent prospective indices of clinical status and guides to treatment design. Sampling bilateral pregenual anterior cingulate cortex (pACC), anterior middle cingulate cortex (aMCC), and thalamus in 40 adult patients and 16 healthy controls, we examined relationships of the neurometabolites glutamate+glutamine (Glx), creatine+phosphocreatine (Cr), and choline-compounds (Cho) with OCD diagnosis and multiple symptom types. The latter included OC core symptoms (Yale-Brown Obsessive-Compulsive Scale - YBOCS), depressive symptoms (Montgomery-Åsberg Depression Rating Scale - MADRS), and general functioning (Global Assessment Scale - GAS). pACC Glx was 9.7% higher in patients than controls. Within patients, Cr and Cho correlated negatively with YBOCS and MADRS, while Cr correlated positively with the GAS. In aMCC, Cr and Cho correlated negatively with MADRS, while Cr in thalamus correlated positively with GAS. These findings present moderate support for glutamatergic and cingulocentric perspectives on OCD. Based on our prior metabolic model of OCD, we offer one possible interpretation of these group and correlational effects as consequences of a corticothalamic state of elevated glutamatergic receptor activity alongside below-normal glutamatergic transporter activity.
August 2016Idiopathic Subglottic Stenosis: A Comparison of Tracheal Size.
Zaghi S, Alonso J, Orestes M, Kadin N, Hsu W, Berke G.
OBJECTIVE: To assess the size of the cervical and thoracic trachea among female patients with idiopathic subglottic stenosis (SGS). METHODS: Computed tomography (CT) scans of neck/chest from female patients with idiopathic SGS (n = 7) and normal controls (n = 30) were analyzed. Only female patients were included. The diameter and cross-sectional area of the trachea were measured at the level of the subglottic larynx, mid-cervical trachea, and mid-thoracic trachea. Measurements of tracheal size were compared between groups.
July 2016Challenging Diagnosis and Surgical Management of a Symptomatic Sellar Spine.
Chivukula S, Everson R, Linetsky M, Heaney A, Bonelli L, Wang MB, Bergsneider M.
BACKGROUND: The sellar spine is a rare, bony growth that typically arises from the dorsum sellae. Few cases have been described in the literature thus far, and most are asymptomatic and incidentally found. We describe the case of a 19-year-old female in whom a sellar spine was noted to be associated with pituitary glandular deformation and symptomatic optic apparatus compression. CASE DESCRIPTION: The medical records including clinical data, pathologic, and imaging findings pertaining to the single patient presented herein were retrospectively reviewed. The patient underwent resection of the hyperostotic sellar spine for decompression of the optic chiasm and pituitary gland via an endoscopic endonasal approach. She immediately reported complete resolution of her bitemporal visual deficits. Her headaches completely resolved, she had no further transient visual deficits, and all other prior presenting symptoms and signs resolved.
July 2016Prostate Cancer Risk Stratification with Magnetic Resonance Imaging.
Felker ER, Margolis DJ, Nassiri N, Marks LS.
In recent years, multiparametric magnetic resonance imaging (mpMRI) has shown promise for prostate cancer (PCa) risk stratification. mpMRI, often followed by targeted biopsy, can be used to confirm low-grade disease before enrollment in active surveillance. In patients with intermediate or high-risk PCa, mpMRI can be used to inform surgical management. mpMRI has sensitivity of 44% to 87% for detection of clinically significant PCa and negative predictive value of 63% to 98% for exclusion of significant disease. In addition to tumor identification, mpMRI has also been shown to contribute significant incremental value to currently used clinical nomograms for predicting extraprostatic extension. In combination with conventional clinical criteria, accuracy of mpMRI for prediction of extraprostatic extension ranges from 92% to 94%, significantly higher than that achieved with clinical criteria alone. Supplemental sequences, such as diffusion-weighted imaging and dynamic contrast-enhanced imaging, allow quantitative evaluation of cancer-suspicious regions. Apparent diffusion coefficient appears to be an independent predictor of PCa aggressiveness. Addition of apparent diffusion coefficient to Epstein criteria may improve sensitivity for detection of significant PCa by as much as 16%. Limitations of mpMRI include variability in reporting, underestimation of PCa volume and failure to detect clinically significant disease in a small but significant number of cases.
July 2016Reduced Long Axis Strain is Associated with Heart Failure and Cardiovascular Events in the Multi-ethnic Study of Atherosclerosis.
Gjesdal O, Yoneyama K, Mewton N, Wu C, Gomes AS, Hundley G, Prince M, Shea S, Liu K, Bluemke DA, Lima JA.
PURPOSE: To propose long axis strain (LAS), a novel index of global left ventricle (LV) function, as a sensitive and powerful predictor of hard cardiovascular events and heart failure in the Multi-Ethnic Study of Atherosclerosis (MESA). MATERIALS AND METHODS: Strain is an index of relative myocardial deformation, and enables normalization for differences in heart size. Measurement of strain conventionally requires dedicated software and protocols for image acquisition. LAS, however, can be analyzed using a caliper tool from conventional LV long axis magnetic resonance imaging (MRI) cine loops, reflecting the average myocardial contraction in the longitudinal direction. In all, 1651 participants (53% men) of the MESA study, without a history of myocardial infarction or heart failure, were assessed using conventional cine MR images. LV lengths were assessed at end-diastole (EDL ) and end-systole (ESL ), and LAS was calculated as 100*(EDL -ESL )/EDL . Participants were followed for 6.8 ± 1.8 years for a composite endpoint of congestive heart failure or hard cardiovascular events, and the predictive ability of LAS was tested, unadjusted and adjusted for established cardiovascular risk factors.
July 2016Transitions to Different Patterns of Interstitial Lung Disease in Scleroderma with and without Treatment.
Kim HJ, Tashkin DP, Gjertson DW, Brown MS, Kleerup E, Chong S, Belperio JA, Roth MD, Abtin F, Elashoff R, Tseng CH, Khanna D, Goldin JG.
OBJECTIVES: The aim is to investigate whether the 12-month quantitative changes in high-resolution CT (HRCT) measures of interstitial lung disease (ILD) are different, and to understand how they change, in patients with scleroderma-related ILD who receive drug therapy versus placebo. METHODS: HRCT images were acquired at baseline and at 12 months in 83 participants in Scleroderma Lung Study I, a clinical trial comparing treatment with oral cyclophosphamide versus placebo. A computer-aided model was used to quantify the extent of fibrotic reticulation, ground glass and honeycomb patterns and quantitative ILD (QILD: sum of these patterns) in the whole lung and the lung zone (upper, middle or lower) of maximal disease involvement.
July 2016Yttrium-90 Selective Internal Radiation Therapy with Glass Microspheres for Hepatocellular Carcinoma: Current and Updated Literature Review.
Lee EW, Alanis L, Cho SK, Saab S.
Hepatocellular carcinoma is the most common primary liver cancer and it represents the majority of cancer-related deaths in the world. More than 70% of patients present at an advanced stage, beyond potentially curative options. Ytrrium-90 selective internal radiation therapy (Y90-SIRT) with glass microspheres is rapidly gaining acceptance as a potential therapy for intermediate and advanced stage primary hepatocellular carcinoma and liver metastases. The technique involves delivery of Y90 infused glass microspheres via the hepatic arterial blood flow to the appropriate tumor. The liver tumor receives a highly concentrated radiation dose while sparing the healthy liver parenchyma due to its preferential blood supply from portal venous blood. There are two commercially available devices: TheraSphere® and SIR-Spheres®. Although, Y90-SIRT with glass microspheres improves median survival in patients with intermediate and advanced hepatocellular carcinoma and has the potential to downstage hepatocellular carcinoma so that the selected candidates meet the transplantable criteria, it has not gained widespread acceptance due to the lack of large randomized controlled trials. Currently, there are various clinical trials investigating the use of Y90-SIRT with glass microspheres for treatment of hepatocellular carcinoma and the outcomes of these trials may result in the incorporation of Y90-SIRT with glass microspheres into the treatment guidelines as a standard therapy option for patients with intermediate and advanced stage hepatocellular carcinoma.
July 2016Nationwide Trends and Predictors of Inpatient Mortality in 83884 Transjugular Intrahepatic Portosystemic Shunt.
Lee EW, Kuei A, Saab S, Busuttil RW, Durazo F, Han SH, El-Kabany MM, McWilliams JP, Kee ST.
AIM: To evaluate and validate the national trends and predictors of in-patient mortality of transjugular intrahepatic portosystemic shunt (TIPS) in 15 years. METHODS: Using the National Inpatient Sample which is a part of Health Cost and Utilization Project, we identified a discharge-weighted national estimate of 83884 TIPS procedures performed in the United States from 1998 to 2012 using international classification of diseases-9 procedural code 39.1. The demographic, hospital and co-morbility data were analyzed using a multivariant analysis. Using multi-nominal logistic regression analysis, we determined predictive factors related to increases in-hospital mortality. Comorbidity measures are in accordance to the Comorbidity Software designed by the Agency for Healthcare Research and Quality.
July 2016Focal Laser Ablation of Prostate Cancer: Phase I Clinical Trial.
Natarajan S, Raman S, Priester AM, Garritano J, Margolis DJ, Lieu P, Macairan ML, Huang J, Grundfest W, Marks LS.
PURPOSE: Focal laser ablation is an investigational technique to treat prostate cancer in a region confined manner via coagulative necrosis. This phase I trial primarily examines the safety of transrectal magnetic resonance imaging guided (in-bore) focal laser ablation in men with intermediate risk prostate cancer. An exploratory end point is cancer control after 6 months. MATERIALS AND METHODS: In an institutional review board approved trial we studied focal laser ablation in 8 men with intermediate risk prostate cancer diagnosed using magnetic resonance-ultrasound fusion. Focal laser ablation was performed by inserting a cylindrically diffusing, water cooled laser fiber into magnetic resonance visible regions of interest, followed by interstitial heating at 10 to 15 W for up to 3 minutes. Secondary safety monitors (thermal probes) were inserted to assess the accuracy of magnetic resonance thermometry. Comprehensive magnetic resonance-ultrasound fusion biopsy was performed after 6 months. Adverse events and health related quality of life questionnaires were recorded.
July 2016Lung Cancer Screening Update.
Ruchalski KL, Brown K.
Since the release of the US Preventive Services Task Force and Centers for Medicare and Medicaid Services recommendations for lung cancer screening, low-dose chest computed tomography screening has moved from the research arena to clinical practice. Lung cancer screening programs must reach beyond image acquisition and interpretation and engage in a multidisciplinary effort of clinical shared decision-making, standardization of imaging and nodule management, smoking cessation, and patient follow-up. Standardization of radiologic reports and nodule management will systematize patient care, provide quality assurance, further reduce harm, and contain health care costs. Although the National Lung Screening Trial results and eligibility criteria of a heavy smoking history are the foundation for the standard guidelines for low-dose chest computed tomography screening in the United States, currently only 27% of patients diagnosed with lung cancer would meet US lung cancer screening recommendations. Current and future efforts must be directed to better delineate those patients who would most benefit from screening and to ensure that the benefits of screening reach all socioeconomic strata and racial and ethnic minorities. Further optimization of lung cancer screening program design and patient eligibility will assure that lung cancer screening benefits will outweigh the potential risks to our patients.
July 2016Solitaire FR Revascularization Device 4×40: Safety Study and Effectiveness in Preclinical Models.
Wainwright JM, Jahan R.
Recent randomized clinical trials have shown the benefit of stent retrievers for endovascular intervention in patients with acute ischemic stroke. The Solitaire 2 FR 4×40 device was developed to address longer clots as well as procedural difficulties. This study was undertaken to evaluate the safety of the new device in a swine model at 0, 30, and 90 days as well as its in vitro effectiveness. There were no significant differences in the overall animal health, tissue injury, hemorrhagic or thrombogenic events related to device usage. Based on the comparison at multiple time points, the Solitaire 2 4×40 device was similar in safety and usability to the Solitaire 2 4×20 device. Due to the additional length of the device, the Solitaire 2 4×40 device may in fact provide a number of additional technical benefits in the neurothrombectomy treatment of ischemic stroke.
July 2016Radiogenomic Analysis Demonstrates Associations between 18F-Fluoro-2-Deoxyglucose PET, Prognosis, and Epithelial-Mesenchymal Transition in Non-Small Cell Lung Cancer.
Yamamoto S, Huang D, Du L, Korn RL, Jamshidi N, Burnette BL, Kuo MD.
Purpose To investigate whether non-small cell lung cancer (NSCLC) tumors that express high normalized maximum standardized uptake value (SUVmax) are associated with a more epithelial-mesenchymal transition (EMT)-like phenotype. Materials and Methods In this institutional review board-approved study, a public NSCLC data set that contained fluorine 18 ((18)F) fluoro-2-deoxyglucose positron emission tomography (PET) and messenger RNA expression profile data (n = 26) was obtained, and patients were categorized on the basis of measured normalized SUVmax values. Significance analysis of microarrays was then used to create a radiogenomic signature. The prognostic ability of this signature was assessed in a second independent data set that consisted of clinical and messenger RNA expression data (n = 166). Signature concordance with EMT was evaluated by means of validation in a publicly available cell line data set. Finally, by establishing an in vitro EMT lung cancer cell line model, an attempt was made to substantiate the radiogenomic signature with quantitative polymerase chain reaction, and functional assays were performed, including Western blot, cell migration, glucose transporter, and hexokinase assays (paired t test), as well as pharmacologic assays against chemotherapeutic agents (half-maximal effective concentration). Results Differential expression analysis yielded a 14-gene radiogenomic signature (P < .05, false discovery rate [FDR] < 0.20), which was confirmed to have differences in disease-specific survival (log-rank test, P = .01). This signature also significantly overlapped with published EMT cell line gene expression data (P < .05, FDR < 0.20). Finally, an EMT cell line model was established, and cells that had undergone EMT differentially expressed this signature and had significantly different EMT protein expression (P < .05, FDR < 0.20), cell migration, glucose uptake, and hexokinase activity (paired t test, P < .05). Cells that had undergone EMT also had enhanced chemotherapeutic resistance, with a higher half-maximal effective concentration than that of cells that had not undergone EMT (P < .05). Conclusion Integrative radiogenomic analysis demonstrates an association between increased normalized (18)F fluoro-2-deoxyglucose PET SUVmax, outcome, and EMT in NSCLC.
June 2016Thyroid Dysfunction in Children Exposed to Iodinated Contrast Media.
Barr ML, Chiu HK, Li N, Yeh MW, Rhee CM, Casillas J, Iskander PJ, Leung AM.
CONTEXT: Iodinated contrast media (ICM) is routinely used in imaging studies and contains several 100-fold the recommended daily allowance of iodine. OBJECTIVE: To determine whether children exposed to ICM have a higher risk of iodine-induced thyroid dysfunction. DESIGN: This was a single-institution case-control study, examining patients with incident thyroid dysfunction aged less than 18 years from 2001 to 2015. Cases were matched 1:1 to euthyroid controls by age, sex, and race. SETTING: This was a single-institution case-control study occurring at tertiary care center. PARTICIPANTS: Cases were defined as those with thyroid dysfunction (by International Classification of Diseases, Ninth Revision diagnosis codes and/or 2 consecutive abnormal serum TSH values <6 mo apart). We analyzed 870 cases matched to 870 controls (64% female, 51% White). MAIN OUTCOMES MEASURES: Using conditional logistic regression, the association between ICM exposure and the primary outcome, thyroid dysfunction, occurring within 2 years of exposure was assessed.
June 2016Contrast-enhancing Tumor Growth Dynamics of Preoperative, Treatment-naive Human Glioblastoma.
Ellingson BM, Nguyen HN, Lai A, Nechifor RE, Zaw O, Pope WB, Yong WH, Nghiemphu PL, Liau LM, Cloughesy TF.
BACKGROUND: Little is known about the natural growth characteristics of untreated glioblastoma before surgical or therapeutic intervention, because patients are rapidly treated after preliminary radiographic diagnosis. Understanding the growth characteristics of uninhibited human glioblastoma may be useful for characterizing changes in response to therapy. Thus, the objective of the current study was to explore tumor growth dynamics in a cohort of patients with untreated glioblastoma before surgical or therapeutic intervention. METHODS: Ninety-five patients with glioblastoma who had measurable enhancing disease on >2 magnetic resonance imaging scans before surgery were identified. Tumor growth rates were quantified in 4 different ways (the percentage change per day, the absolute rate of change per day, the estimated volumetric doubling time, and the radial expansion rate) using 3 different approaches (bidirectional product, enhancing disease, and total lesion volume).
June 2016Local Therapy for Limited Metastatic Non-Small Cell Lung Cancer: What Are the Options and Is There a Benefit?
Iyengar P, Lau S, Donington JS, Suh RD.
Distant metastasis is common in non-small cell lung cancer (NSCLC) and typically associated with poor prognosis. Aggressive local therapy including surgery and/or radiation for limited metastatic disease from colorectal cancer and sarcoma is associated with survival benefit and has become part of the standard of care. In this article, we review the literature and ongoing studies concerning surgery, radiation, and radiofrequency ablation for oligometastatic NSCLC.
June 2016Aneurysm Study of Pipeline in an Observational Registry (ASPIRe).
Kallmes DF, Brinjikji W, Boccardi E, Ciceri E, Diaz O, Tawk R, Woo H, Jabbour P, Albuquerque F, Chapot R, Bonafe A, Dashti SR, Delgado Almandoz JE, Given C 2nd, Kelly ME, Cross DT 3rd,Duckwiler G, Razack N, Powers CJ, Fischer S, Lopes D, Harrigan MR, Huddle D, Turner R 4th, Zaidat OO, Defreyne L, Pereira VM, Cekirge S, Fiorella D, Hanel RA, Lylyk P, McDougall C, Siddiqui A, Szikora I, Levy E.
BACKGROUND AND OBJECTIVE: Few prospective studies exist evaluating the safety and efficacy of the Pipeline Embolization Device (PED) in the treatment of intracranial aneurysms. The Aneurysm Study of Pipeline In an observational Registry (ASPIRe) study prospectively analyzed rates of complete aneurysm occlusion and neurologic adverse events following PED treatment of intracranial aneurysms. MATERIALS AND METHODS: We performed a multicenter study prospectively evaluating patients with unruptured intracranial aneurysms treated with PED. Primary outcomes included (1) spontaneous rupture of the Pipeline-treated aneurysm; (2) spontaneous nonaneurysmal intracranial hemorrhage (ICH); (3) acute ischemic stroke; (4) parent artery stenosis, and (5) permanent cranial neuropathy. Secondary endpoints were (1) treatment success and (2) morbidity and mortality at the 6-month follow-up. Vascular imaging was evaluated at an independent core laboratory.
June 2016Value of Cardiac MRI for Evaluation of Chronic Chagas Disease Cardiomyopathy.
Lee-Felker SA, Thomas M, Felker ER, Traina M, Salih M, Hernandez S, Bradfield J, Lee M, Meymandi S.
AIM: To determine whether cardiac magnetic resonance imaging (cMRI) is more sensitive than electrocardiogram (ECG) and echocardiogram (ECHO) for detecting myocardial involvement in a Latin American migrant population with untreated Chagas disease (CD) in the United States. MATERIALS AND METHODS: All untreated CD patients with ECG and ECHO examinations who underwent cMRI at Olive View-UCLA Medical Center from September 2010 to December 2013 (n=81) were analysed in three groups: Group 1, normal ECG and ECHO examinations (n=50); Group 2, abnormal ECG and normal ECHO examinations (n=10); and Group 3, abnormal ECHO examination (n=21). Frequencies of ECG, ECHO, and cMRI findings were compared across groups.
June 2016Early Arrival at the Emergency Department is Associated with Better Collaterals, Smaller Established Infarcts and Better Clinical Outcomes with Endovascular Stroke Therapy: SWIFT study.
Liebeskind DS, Jahan R, Nogueira RG, Jovin TG, Lutsep HL, Saver JL; SWIFT Investigators.
BACKGROUND AND PURPOSE: Increasing time from symptom onset to emergency department arrival may incur greater ischemic injury and decreased likelihood of good outcomes after acute stroke therapy. The impact of time may be assessed bythe extent of acute CT changes, status of collateral vessels, and clinical outcomes. METHODS: The SOLITAIRE FR With the Intention For Thrombectomy (SWIFT) trial comparing two neurothrombectomy treatments was analyzed by time, Alberta Stroke Program Early CT Scores (ASPECTS), angiographic collaterals, and 90-day modified Rankin Scale outcomes. We determined the interaction of time with ASPECTS, collateral grade, reperfusion, and clinical outcomes, with established determinants of angiographic and clinical outcomes as covariates.
June 2016MR-TRUS Fusion Biopsy.
The leading application of multiparametric magnetic resonance imaging (mpMRI) of the prostate is for lesion detection with the intention of tissue sampling (biopsy). Although direct in-bore magnetic resonance (MR)-guided biopsy allows for confirmation of the biopsy site, this can be expensive, time-consuming, and most importantly limited in availability. MR-transrectal ultrasound (MR-TRUS) image fusion targeted biopsy (TBx) allows for lesions identified on MRI to be targeted with the ease, efficiency, and availability of ultrasound.The learning objectives are optimized mpMRI protocol and reporting for image fusion targeted biopsy; methods of TRUS TBx; performance and limitations of MR-TRUS TBx; future improvements and applications.
June 2016Lung Transplant Outcomes in Systemic Sclerosis with Significant Esophageal Dysfunction. A Comprehensive Single-Center Experience.
Miele CH, Schwab K, Saggar R, Duffy E, Elashoff D, Tseng CH, Weigt S, Charan D, Abtin F, Johannes J, Derhovanessian A, Conklin J, Ghassemi K, Khanna D, Siddiqui O, Ardehali A, Hunter C, Kwon M, Biniwale R, Lo M, Volkmann E, Torres Barba D, Belperio JA, Sayah D, Mahrer T, Furst DE, Kafaja S, Clements P, Shino M, Gregson A, Kubak B, Lynch JP 3rd, Ross D, Saggar R.
RATIONALE: Consideration of lung transplantation in patients with systemic sclerosis (SSc) remains guarded, often due to the concern for esophageal dysfunction and the associated potential for allograft injury and suboptimal post-lung transplantation outcomes. OBJECTIVES: The purpose of this study was to systematically report our single-center experience regarding lung transplantation in the setting of SSc, with a particular focus on esophageal dysfunction. METHODS: We retrospectively reviewed all lung transplants at our center from January 1, 2000 through August 31, 2012 (n = 562), comparing the SSc group (n = 35) to the following lung transplant diagnostic subsets: all non-SSc (n = 527), non-SSc diffuse fibrotic lung disease (n = 264), and a non-SSc matched group (n = 109). We evaluated post-lung transplant outcomes, including survival, primary graft dysfunction, acute rejection, bronchiolitis obliterans syndrome, and microbiology of respiratory isolates. In addition, we defined severe esophageal dysfunction using esophageal manometry and esophageal morphometry criteria on the basis of chest computed tomography images. For patients with SSc referred for lung transplant but subsequently denied (n = 36), we queried the reason(s) for denial with respect to the concern for esophageal dysfunction.
June 2016Angiographic Structural Differentiation between Native Arteriogenesis and Therapeutic Synangiosis in Intracranial Arterial Steno-Occlusive Disease.
Ooi YC, Laiwalla AN, Liou R, Gonzalez NR.
BACKGROUND AND PURPOSE: Encephaloduroarteriosynangiosis has been shown to generate collateral vessels from the extracranial-to-intracranial circulation in patients with Moyamoya disease and intracranial arterial steno-occlusive disease. The mechanisms involved are not well-understood. We hypothesized that angiogenesis is the leading mechanism forming collaterals after encephaloduroarteriosynangiosis because there are no pre-existing connections. Angiogenesis-generated collaterals should exhibit higher architectural complexity compared with innate collaterals. MATERIALS AND METHODS: Pre- and postoperative digital subtraction angiograms were analyzed in patients enrolled in a prospective trial of encephaloduroarteriosynangiosis surgery. Branching angioscore, tortuosity index, and local connected fractal dimension were compared between innate and postoperative collaterals.
June 2016Mechanical Thrombectomy for Acute Ischemic Stroke with Cerebral Microbleeds.
Shi ZS, Duckwiler GR, Jahan R, Tateshima S, Gonzalez NR, Szeder V, Saver JL, Kim D, Ali LK, Starkman S, Vespa PM, Salamon N, Villablanca JP, Viñuela F, Feng L, Loh Y, Liebeskind DS.
BACKGROUND: The influence of cerebral microbleeds (CMBs) on post-thrombolytic hemorrhagic transformation (HT) in patients with acute ischemic stroke remains controversial. OBJECTIVE: To investigate the association of CMBs with HT and clinical outcomes among patients with large-vessel occlusion strokes treated with mechanical thrombectomy. METHODS: We analyzed patients with acute stroke treated with Merci Retriever, Penumbra system or stent-retriever devices. CMBs were identified on pretreatment T2-weighted, gradient-recall echo MRI. We analyzed the association of the presence, burden, and distribution of CMBs with HT, procedural complications, in-hospital mortality, and clinical outcome.
June 2016Using Phrases and Document Metadata to Improve Topic Modeling of Clinical Reports.
Speier W, Ong MK, Arnold CW.
Probabilistic topic models provide an unsupervised method for analyzing unstructured text, which have the potential to be integrated into clinical automatic summarization systems. Clinical documents are accompanied by metadata in a patient's medical history and frequently contains multiword concepts that can be valuable for accurately interpreting the included text. While existing methods have attempted to address these problems individually, we present a unified model for free-text clinical documents that integrates contextual patient- and document-level data, and discovers multi-word concepts. In the proposed model, phrases are represented by chained n-grams and a Dirichlet hyper-parameter is weighted by both document-level and patient-level context. This method and three other Latent Dirichlet allocation models were fit to a large collection of clinical reports. Examples of resulting topics demonstrate the results of the new model and the quality of the representations are evaluated using empirical log likelihood. The proposed model was able to create informative prior probabilities based on patient and document information, and captured phrases that represented various clinical concepts. The representation using the proposed model had a significantly higher empirical log likelihood than the compared methods. Integrating document metadata and capturing phrases in clinical text greatly improves the topic representation of clinical documents. The resulting clinically informative topics may effectively serve as the basis for an automatic summarization system for clinical reports.
June 2016Aneurysm Pressure Measurement Before and After Placement of a Pipeline Stent: Feasibility Study Using a 0.014 Inch Pressure Wire for Coronary Intervention.
Tateshima S, Jones JG, Mayor Basto F, Viñuela F, Duckwiler GR.
Flow-diverting stents have provided a new endovascular capacity to reconstruct an intracranial aneurysm with its diseased parent artery. The results of first-generation flow diversion stents have been encouraging, with even large or giant treated aneurysms achieving complete angiographic occlusion at 12-month follow-up. Numerous clinical reports have described a slow progressive thrombosis pattern and gradual increase in rate of complete aneurysm obliteration over time. Despite promising early results, some complications specific to flow-diverting stents have been encountered. Chief among them is delayed aneurysm rupture. This complication did not emerge with stent-assisted coil embolization of intracranial aneurysms, and the underlying cause has not been established. However, new evidence suggests that persistent, or even increased, aneurysm pressure after stent placement may play a role in some delayed ruptures. We sought to evaluate this phenomenon by measuring intrasaccular pressure before and after stent placement using two different 0.014 inch coronary pressure measurement wires. Two patients with giant internal carotid artery aneurysms treated with flow-diverting stents were evaluated. Before and after stent deployment, intrasaccular aneurysm and systemic arterial pressures were recorded for 60 s and compared. In both cases, intrasaccular pressure measurement with the use of 0.014 inch pressure wire system was feasible; the pressure wires could be pushed out of the microcatheter placed in the aneurysms without friction or unexpected microcatheter motion. Despite successful flow-diverting stent deployment and angiographic flow diversion effects with excellent wall opposition across the aneurysm necks, there was no significant difference between intrasaccular and systemic pressures.
June 2016Consumers' Patient Portal Preferences and Health Literacy: A Survey Using Crowdsourcing.
Zide M, Caswell K, Peterson E, Aberle DR, Bui AA, Arnold CW.
BACKGROUND: eHealth apps have the potential to meet the information needs of patient populations and improve health literacy rates. However, little work has been done to document perceived usability of portals and health literacy of specific topics. OBJECTIVE: Our aim was to establish a baseline of lung cancer health literacy and perceived portal usability. METHODS: A survey based on previously validated instruments was used to assess a baseline of patient portal usability and health literacy within the domain of lung cancer. The survey was distributed via Amazon's Mechanical Turk to 500 participants.
May 2016Early Experience with AngioVac Aspiration in the Pulmonary Arteries.
Al-Hakim R, Park J, Bansal A, Genshaft S, Moriarty JM.
Five consecutive cases in which the AngioVac aspiration cannula was used for the management of pulmonary embolism (PE) were retrospectively reviewed. Four cases (80%) presented with massive PE, and two (40%) were technically successful (reduction in Miller index ≥ 5). Four patients (80%) died at a mean of 7.3 days after the procedure, including one death related to right ventricular free wall perforation. Although the AngioVac aspiration cannula has shown clinical promise in a variety of clinical applications, early experience in the pulmonary arteries has shown limited success, and further study and careful patient selection are required.
May 2016In-bore Magnetic Resonance-guided Transrectal Biopsy for the Detection of Clinically Significant Prostate Cancer.
Felker ER, Lee-Felker SA, Feller J, Margolis DJ, Lu DS, Princenthal R, May S, Cohen M, Huang J, Yoshida J, Greenwood B, Kim HJ, Raman SS.
PURPOSE: To determine the safety and efficacy of in-bore magnetic resonance-guided prostate biopsy (MRGB) for detection of clinically significant disease (CSD) in untreated men with known or suspected prostate cancer (PCa). METHODS: 512 patients underwent multiparametric magnetic resonance imaging (Mp-MRI) followed by MRGB at one of three centers in this IRB-approved, HIPAA-compliant, retrospective study. Exclusion criteria were prior prostate cancer therapy and incomplete Mp-MRI (n = 51). Patients (n = 461) were analyzed in two subcohorts: no prior PCa (NP) (n = 381) and active surveillance (AS) (n = 80). Detection rates of PCa and CSD (Gleason Score ≥3 + 4) were calculated and compared among subcohorts and by Mp-MRI assessment grade. Logistic regression was performed to identify predictors for detection of PCa and CSD.
May 2016Serial Magnetic Resonance Imaging in Active Surveillance of Prostate Cancer: Incremental Value.
Felker ER, Wu J, Natarajan S, Margolis DJ, Raman SS, Huang J, Dorey F, Marks LS.
PURPOSE: We assessed whether changes in serial multiparametric magnetic resonance imaging can help predict the pathological progression of prostate cancer in men on active surveillance. MATERIALS AND METHODS: A retrospective cohort study was conducted of 49 consecutive men with Gleason 6 prostate cancer who underwent multiparametric magnetic resonance imaging at baseline and again more than 6 months later, each followed by a targeted prostate biopsy, between January 2011 and May 2015. We evaluated whether progression on multiparametric magnetic resonance imaging (an increase in index lesion suspicion score, increase in index lesion volume or decrease in index lesion apparent diffusion coefficient) could predict pathological progression (Gleason 3 + 4 or greater on subsequent biopsy, in systematic or targeted cores). Diagnostic performance of multiparametric magnetic resonance imaging was determined with and without clinical data using a binary logistic regression model.
May 2016Implementation and Results of a Percutaneous Renal Allograft Biopsy Protocol to Reduce Complication Rate.
Li CH, Traube LE, Lu DS, Raman SS, Danovitch GM, Gritsch HA, McWilliams JP.
Percutaneous renal transplant biopsy (PRTB) is the gold standard for evaluating allograft rejection after renal transplant. Hemorrhage is the predominant complication. We describe the implementation of a standardized protocol for PRTB at a single institution, with the aim of reducing bleeding complications. Utilizing the plan-do-study-act model for quality improvement, we created and deployed a protocol centered on controlling patient's hypertension, platelet function, and anticoagulation status. The 4-year study encompassed a total of 880 PRTBs, before and after implementation of the protocol. Total complication rate, which was 5.8% in the 2 years leading up to implementation of the protocol, was reduced to 2.9% after the protocol was introduced (P = .04). A standardized approach to PRTB can potentially lower complication rates; we present a framework for implementating a quality improvement protocol at other institutions.
May 2016Why We Need a Vendor Neutral Specification for Delineating Prostate Cancer with mpMRI.
Margolis DJ, Westphalen AC, Haider MA.
Despite being the most common non-cutaneous cancer and second leading cause of cancer death in American men, the United States Preventive Service Task Force recommends against screening for prostate cancer because of the resultant overtreatment of indolent disease. With the demonstrated ability of multiparametric MRI (mpMRI) to identify cancer and the ability of mpMRI combined with transrectal ultrasound (TRUS) MRI fusion biopsy to increase the yield of significant cancer while decreasing the yield of insignificant cancer, there has been marked growth in volumes and indications for mpMRI of the prostate.
May 2016Brain Biopsy in Atypical Dementia and Primary Angiitis of the Central Nervous System-reply.
Magaki S, Gardner T, Khanlou N, Yong WH, Salamon N, Vinters HV.
Dear Editor, We thank the authors for their interest in our study on the use of brain biopsy in evaluating neurologic decline of unknown etiology. Regarding the first point raised, brain biopsies in immunodeficient patients are well established, which the authors also state in their article. This may change, specifically in HIV-positive patients in the era of highly active antiretroviral therapy (HAART), and we look forward to the authors' meta-analysis. In a study by Rosenow and Hirschfeld, despite a sharp decline in the number of brain biopsies in acquired immunodeficiency syndrome patients performed in the HAART era, the diagnostic yield was high both before (91.3%) and after (96%) the introduction of HAART; the most common diagnoses were lymphoma followed by progressive multifocal leukoencephalopathy, with brain biopsy clearly retaining its utility in select patients. They recommend early brain biopsy after toxoplasmosis, one of the most common intracranial complications in acquired immunodeficiency syndrome, has been ruled out by serology
May 2016Lung Cancer Incidence and Mortality in National Lung Screening Trial Participants Who Underwent Low-dose CT Prevalence Screening: a Retrospective Cohort Analysis of a Randomised, Multicentre, Diagnostic Screening Trial.
Patz EF Jr, Greco E, Gatsonis C, Pinsky P, Kramer BS, Aberle DR.
BACKGROUND: Annual low-dose CT screening for lung cancer has been recommended for high-risk individuals, but the necessity of yearly low-dose CT in all eligible individuals is uncertain. This study examined rates of lung cancer in National Lung Screening Trial (NLST) participants who had a negative prevalence (initial) low-dose CT screen to explore whether less frequent screening could be justified in some lower-risk subpopulations. METHODS: We did a retrospective cohort analysis of data from the NLST, a randomised, multicentre screening trial comparing three annual low-dose CT assessments with three annual chest radiographs for the early detection of lung cancer in high-risk, eligible individuals (aged 55-74 years with at least a 30 pack-year history of cigarette smoking, and, if a former smoker, had quit within the past 15 years), recruited from US medical centres between Aug 5, 2002, and April 26, 2004. Participants were followed up for up to 5 years after their last annual screen. For the purposes of this analysis, our cohort consisted of all NLST participants who had received a low-dose CT prevalence (T0) screen. We determined the frequency, stage, histology, study year of diagnosis, and incidence of lung cancer, as well as overall and lung cancer-specific mortality, and whether lung cancers were detected as a result of screening or within 1 year of a negative screen. We also estimated the effect on mortality if the first annual (T1) screen in participants with a negative T0 screen had not been done. The NLST is registered with ClinicalTrials.gov, number NCT00047385.
May 2016FG-3019 Anti-connective Tissue Growth Factor Monoclonal Antibody: Results of an Open-label Clinical Trial in Idiopathic Pulmonary Fibrosis.
Raghu G, Scholand MB, de Andrade J, Lancaster L, Mageto Y, Goldin J, Brown KK, Flaherty KR, Wencel M, Wanger J, Neff T, Valone F, Stauffer J, Porter S.
FG-3019 is a fully human monoclonal antibody that interferes with the action of connective tissue growth factor, a central mediator in the pathogenesis of fibrosis.This open-label phase 2 trial evaluated the safety and efficacy of two doses of FG-3019 administered by intravenous infusion every 3 weeks for 45 weeks in patients with idiopathic pulmonary fibrosis (IPF). Subjects had a diagnosis of IPF within the prior 5 years defined by either usual interstitial pneumonia (UIP) pattern on a recent high-resolution computed tomography (HRCT) scan, or a possible UIP pattern on HRCT scan and a recent surgical lung biopsy showing UIP pattern. Pulmonary function tests were performed every 12 weeks, and changes in the extent of pulmonary fibrosis were measured by quantitative HRCT scans performed at baseline and every 24 weeks. FG-3019 was safe and well-tolerated in IPF patients participating in the study. Changes in fibrosis were correlated with changes in pulmonary function.Further investigation of FG-3019 in IPF with a placebo-controlled clinical trial is warranted and is underway.
May 2016Commentary Regarding the Inter-reader Reproducibility of PI-RADS Version 2.
Rosenkrantz AB, Margolis DJ.
For prostate MRI to achieve maximal clinical impact, consistency in radiological reporting is critical. Recognizing this need, the American College of Radiology, European Society of Uroradiology, and AdMeTech Foundation convened an international expert panel that developed the Prostate Imaging Radiology and Data System (PI-RADS) Version 2 (V2) to standardize prostate MRI interpretation and reporting. PI-RADS V2 greatly expanded upon the earlier PI-RADS Version 1 released in 2012, seeking to be both more comprehensive and improve the system's usability in clinical practice. Since its public release in late 2015, PI-RADS V2 has been the subject of considerable interest by radiologists and urologists, undergoing increasing clinical adoption and being the subject of educational courses and a number of peer-reviewed publications. As PI-RADS V2 grows in popularity, a natural and important question is just how successful the system has been in achieving its intended aim of standardizing prostate MRI interpretation.
May 2016Preliminary Outcome of Microwave Ablation of Hepatocellular Carcinoma: Breaking the 3-cm Barrier?
Thamtorawat S, Hicks RM, Yu J, Siripongsakun S, Lin WC, Raman SS, McWilliams JP, Douek M,Bahrami S, Lu DS.
PURPOSE: To evaluate preliminary outcomes after microwave ablation (MWA) of hepatocellular carcinoma (HCC) up to 5 cm and to determine the influence of tumor size. MATERIALS AND METHODS: Electronic records were searched for HCC and MWA. Between January 2011 and September 2014, 173 HCCs up to 5 cm were treated by MWA in 129 consecutive patients (89 men, 40 women; mean age, 66.9 y ± 9.5). Tumor characteristics related to local tumor progression and primary and secondary treatment efficacy were evaluated by univariate analysis. Outcomes were compared between tumors ≤ 3 cm and tumors > 3 cm.
April 2016Saving the Starfish: World Federation of Pediatric Imaging (WFPI) Development, Work to Date, and Membership Feedback on International Outreach.
Dehaye A, Silva CT, Darge K, Prabhu SP, Andronikou S, Laya BF, Coley BD, Boechat MI.
Once upon a time there was an old man who used to take regular walks on the beach. One day, after a big storm, he found the beach littered with starfish as far as the eye could see. Then he noticed a small boy who kept bending down to pick up an object and throw it into the sea. 'Good morning!' the old man called out. 'May I ask what you are doing?' The young boy called back: 'Throwing starfish into the sea. The tide has washed them up onto the beach and they're stuck. When the sun gets high, they'll die unless I throw them back.' The old man replied, 'But there must be tens of thousands of starfish on this beach. I'm afraid you won't make much of a difference.' The boy bent down, picked up yet another starfish and threw it as far as he could into the sea. Then he turned, smiled and said, 'I made a difference to that one!'
April 2016Topographical Distribution of Epileptogenic Tubers in Patients With Tuberous Sclerosis Complex.
Ellingson BM, Hirata Y, Yogi A, Karavaeva E, Leu K, Woodworth DC, Harris RJ, Enzmann DR, Wu JY, Mathern GW, Salamon N.
Tuberous sclerosis complex is a multisystem genetic syndrome often affecting the central nervous system. The purpose of the current study was to identify topographical patterns in the distribution specific to epileptogenic (n = 37) and nonepileptogenic (n = 544) tubers throughout the brain for a cohort of 23 tuberous sclerosis complex patients with a history of seizures. Tubers localized to the inferior parietal lobes, middle frontal lobes, middle temporal lobes, or central sulcus regions were associated with a high frequency of epileptogenic tubers. Epileptogenic tubers occurred statistically more frequently within the inferior parietal lobe and within the central sulcus region in children younger than 1 or between 1 and 3 years old, respectively. Results imply seizure activity in tuberous sclerosis complex patients can be associated with the location of cortical tubers.
April 2016Endovascular Thrombectomy After Large-vessel Ischaemic Stroke: A Meta-analysis of Individual Patient Data from Five Randomised Trials.
Goyal M, Menon BK, van Zwam WH, Dippel DW, Mitchell PJ, Demchuk AM, Dávalos A, Majoie CB, van der Lugt A, de Miquel MA, Donnan GA, Roos YB, Bonafe A, Jahan R, Diener HC, van den Berg LA, Levy EI, Berkhemer OA, Pereira VM, Rempel J, Millán M, Davis SM, Roy D, Thornton J, Román LS, Ribó M, Beumer D, Stouch B, Brown S, Campbell BC, van Oostenbrugge RJ, Saver JL, Hill MD, Jovin TG; HERMES collaborators.
BACKGROUND: In 2015, five randomised trials showed efficacy of endovascular thrombectomy over standard medical care in patients with acute ischaemic stroke caused by occlusion of arteries of the proximal anterior circulation. In this meta-analysis we, the trial investigators, aimed to pool individual patient data from these trials to address remaining questions about whether the therapy is efficacious across the diverse populations included. METHODS: We formed the HERMES collaboration to pool patient-level data from five trials (MR CLEAN, ESCAPE, REVASCAT, SWIFT PRIME, and EXTEND IA) done between December, 2010, and December, 2014. In these trials, patients with acute ischaemic stroke caused by occlusion of the proximal anterior artery circulation were randomly assigned to receive either endovascular thrombectomy within 12 h of symptom onset or standard care (control), with a primary outcome of reduced disability on the modified Rankin Scale (mRS) at 90 days. By direct access to the study databases, we extracted individual patient data that we used to assess the primary outcome of reduced disability on mRS at 90 days in the pooled population and examine heterogeneity of this treatment effect across prespecified subgroups. To account for between-trial variance we used mixed-effects modelling with random effects for parameters of interest. We then used mixed-effects ordinal logistic regression models to calculate common odds ratios (cOR) for the primary outcome in the whole population (shift analysis) and in subgroups after adjustment for age, sex, baseline stroke severity (National Institutes of Health Stroke Scale score), site of occlusion (internal carotid artery vs M1 segment of middle cerebral artery vs M2 segment of middle cerebral artery), intravenous alteplase (yes vs no), baseline Alberta Stroke Program Early CT score, and time from stroke onset to randomisation.
April 2016A Data-driven Approach for Quality Assessment of Radiologic Interpretations.
Hsu W, Han SX, Arnold CW, Bui AA, Enzmann DR.
Given the increasing emphasis on delivering high-quality, cost-efficient healthcare, improved methodologies are needed to measure the accuracy and utility of ordered diagnostic examinations in achieving the appropriate diagnosis. Here, we present a data-driven approach for performing automated quality assessment of radiologic interpretations using other clinical information (e.g., pathology) as a reference standard for individual radiologists, subspecialty sections, imaging modalities, and entire departments. Downstream diagnostic conclusions from the electronic medical record are utilized as "truth" to which upstream diagnoses generated by radiology are compared. The described system automatically extracts and compares patient medical data to characterize concordance between clinical sources. Initial results are presented in the context of breast imaging, matching 18 101 radiologic interpretations with 301 pathology diagnoses and achieving a precision and recall of 84% and 92%, respectively. The presented data-driven method highlights the challenges of integrating multiple data sources and the application of information extraction tools to facilitate healthcare quality improvement.
April 2016Usefulness of Transcranial Doppler for Detecting Pulmonary Arteriovenous Malformations in Hereditary Hemorrhagic Telangiectasia.
Kijima Y, Gevorgyan R, McWilliams JP, Miller N, Noureddin N, Tobis JM.
The aim of this study was to assess transcranial Doppler (TCD) as a screening test for pulmonary arteriovenous malformation (PAVM) in patients with hereditary hemorrhagic telangiectasia (HHT). This retrospective study included suspected patients with HHT who were screened for PAVM with a TCD and a chest computed tomography (CT) study. The results of TCD and CT were compared to evaluate the usefulness of TCD for detecting PAVM. A TCD Spencer grade ≥3 was defined as positive for a significant right-to-left shunt (RLS). The diameter of the pulmonary arteries feeding the PAVM was measured by calipers from the CT study. In 86 subjects from 74 families with HHT, the sensitivity of TCD for identifying a PAVM at rest was 98% and post-Valsalva was 100%. Specificity was 58% and 35%, respectively, presumably due to pulmonary shunts too small to recognize on CT. Of the patients with HHT who were referred for embolization therapy for their PAVMs, all 20 had TCD grade ≥3. In patients who were diagnosed with a PAVM by chest CT, patients with TCD grade ≥5 had a significantly larger sum of artery diameters feeding the PAVMs compared to those with grade ≤4 (5.0 ± 3.2 mm vs 2.6 ± 1.9 mm, p = 0.01). In conclusion, a TCD examination for evaluating RLS is sensitive for identifying PAVM in patients with HHT and is useful in quantitating the degree of RLS flow. The sensitivity of the TCD examination makes it a useful screening test without radiation in HHT subjects to determine which patients need to undergo CT evaluation to identify PAVMs.
April 2016Microwave Ablation of Liver Tumors: Degree of Tissue Contraction as Compared to RF Ablation.
Lee JK, Siripongsakun S, Bahrami S, Raman SS, Sayre J, Lu DS.
PURPOSE: To compare the amount of tissue contraction after microwave (MW) versus radiofrequency (RF) ablation of liver tumors. MATERIALS AND METHODS: Seventy-five hepatic tumors in 65 patients who underwent percutaneous MW or RF ablations were included in this retrospective study. All patients underwent MRI within 6 months before the ablation and 24 h after the procedure. Two blinded radiologists, by consensus, performed measurements on the corresponding series of pre and post-ablation MRI. Absolute and relative contraction of liver, tumor, and control were calculated and compared.
April 2016Renal Denervation: A Novel Therapy at the Crossroads of Imaging, Intervention, and Innovation.
Moriarty JM, Tung R, Bradfield JS, McWilliams J, Lee EW, Kuo MD.
Hypertension (HTN) is one of the most significant medical problems affecting society today. The estimated 76 million Americans with hypertension represent a significant public health problem, contributing to cardiac, vascular, renal, and neurovascular morbidity and mortality. HTN is the most common indication for lifelong pharmacologic treatment, mainly because of the incontrovertible reductions in cardiovascular events with blood pressure (BP) reduction and control. However, despite the availability and potency of multiple different antihypertensive drugs, up to half of American patients have BPs above the recommended target. Given the overwhelming evidence of both the cost to society of HTN and the benefits that are accrued from improved BP control, alternatives or adjuncts to current management options have been sought to aid in treatment of these patients. Over the past few years, a device-based approach involving modulation of the autonomic nervous system, termed renal denervation, has evolved to meet this challenge. With early trials showing startlingly good results, with few side effects, multiple devices were fast-tracked to clinical trials and hence to the market. However, larger trials have shone an unfavorable light on the field, with concerns about the short- and long-term effectiveness, diverting attention back to operational and procedural details. Despite this, image-guided manipulation of the sympathetic nervous system to treat HTN remains a fertile area of laboratory and clinical research.
April 2016Physiologic MRI for Assessment of Response to Therapy and Prognosis in Glioblastoma.
Shiroishi MS, Boxerman JL, Pope WB.
Aside from bidimensional measurements from conventional contrast-enhanced MRI, there are no validated or FDA-qualified imaging biomarkers for high-grade gliomas. However, advanced functional MRI techniques, including perfusion- and diffusion-weighted MRI, have demonstrated much potential for determining prognosis, predicting therapeutic response, and assessing early treatment response. They may also prove useful for differentiating pseudoprogression from true progression after temozolomide chemoradiation and pseudoresponse from true response after anti-angiogenic therapy. This review will highlight recent developments using these techniques and emphasize the need for technical standardization and validation in prospective studies in order for these methods to become incorporated into standard-of-care imaging for brain tumor patients.
April 2016Qualitative and Quantitative Gadoxetic Acid-enhanced MR Imaging Helps Subtype Hepatocellular Adenomas.
Tse JR, Naini BV, Lu DS, Raman SS.
Purpose To determine which clinical variables and gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging features are associated with histologically proved hepatocellular adenoma (HCA) genotypic subtypes. Materials and Methods In this institutional review board-approved and Health Insurance Portability and Accountability Act-compliant study, clinical information and MR images of 49 histologically proved HCAs from January 2002 to December 2013 (21 patients; mean age, 39 years; age range, 15-59 years) were retrospectively reviewed by two radiologists. Qualitative and quantitative imaging features, including the signal intensity ratio relative to liver in each phase, were studied. HCA tissues were stained with subtype-specific markers and subclassified by a pathologist. Clinical and imaging data were correlated with pathologic findings and compared by using Fisher exact or t test, with a Bonferroni correction for multiple comparisons. Results Forty-nine HCAs were subclassified into 14 inflammatory, 20 hepatocyte nuclear factor (HNF)-1α-mutated, one β-catenin-activated, and 14 unclassified lesions. Intralesional steatosis was exclusively seen in HNF-1α-mutated lesions. Marked hyperintensity on T2-weighted images was seen in 12 of 14 (86%) inflammatory lesions compared with four of 21 (19%) HNF-1α-mutated, seven of 14 (50%) unclassified, and zero of one (0%) β-catenin-activated lesion. Two large lesions (one β-catenin-activated and one unclassified) transformed into hepatocellular carcinomas and were the only lesions to enhance with marked heterogeneity. In the hepatobiliary phase, all HCA subtypes were hypoenhancing compared with surrounding liver parenchyma, and they reached their nadir signal intensity by 10 minutes after the administration of contrast material before plateauing. HNF-1α-mutated lesions had the lowest lesion signal intensity ratio of 0.47 ± 0.09, compared with 0.73 ± 0.18 for inflammatory lesions (P = .0004), 0.82 for the β-catenin-activated lesion, and 0.73 ± 0.06 for the unclassified lesion (P = .00002). Conclusion In this study, all HCA subtypes were hypoenhancing at Gd-EOB-DTPA-enhanced MR imaging in the hepatobiliary phase and reached their nadir signal intensity at 10 minutes. HNF-1α-mutated lesions could be distinguished from other subtypes by having the lowest lesion signal intensity ratio.
April 2016Treatments for Kienböck Disease: What the Radiologist Needs to Know.
White C, Benhaim P, Plotkin B.
The etiology of Kienböck disease, or avascular necrosis of the lunate, is controversial, and there are a myriad of treatments aimed at correcting the various hypothesized pathologies. Interventions to reduce mechanical stress on the lunate have been used for decades, including radial osteotomy with or without radial shortening, ulnar lengthening and metaphyseal core decompression procedures. However, these procedures require preservation of lunate architecture. Newer procedures to revascularize the lunate bone have emerged in the last 10 years, such as pedicled corticoperiosteal vascularized bone grafting. Once there is collapse of the radiocarpal joint or midcarpal arthrosis, the conventional treatments have included proximal row carpectomy and complete or partial wrist joint arthrodesis. Newer salvage procedures such as lunate excision with autologous or synthetic interposition grafts are now being used when possible. As this disease is relatively rare, radiologists may not be familiar with the expected post-operative radiologic findings and complications, especially of the newer treatments. The goals of this paper are to review the available treatment options and their expected appearance on postoperative imaging, with discussion of possible complications when appropriate.
March 2016Supranormal Thymic Output Up to 2 Decades After HIV-1 Infection.
Aguilera-Sandoval CR, Yang OO, Jojic N, Lovato P, Chen DY, Boechat MI, Cooper P, Zuo J, Ramirez C, Belzer M, Church JA, Krogstad P.
OBJECTIVES: AIDS is caused by CD4 T-cell depletion. Although combination antiretroviral therapy can restore blood T-cell numbers, the clonal diversity of the reconstituting cells, critical for immunocompetence, is not well defined. METHODS: We performed an extensive analysis of parameters of thymic function in perinatally HIV-1-infected (n = 39) and control (n = 28) participants ranging from 13 to 23 years of age. CD4 T cells including naive (CD27 CD45RA) and recent thymic emigrant (RTE) (CD31/CD45RA) cells, were quantified by flow cytometry. Deep sequencing was used to examine T-cell receptor (TCR) sequence diversity in sorted RTE CD4 T cells.
March 2016A Novel Quantitative Computed Tomographic Analysis Suggests How Sirolimus Stabilizes Progressive Air Trapping in Lymphangioleiomyomatosis.
Argula RG, Kokosi M, Lo P, Kim HJ, Ravenel JG, Meyer C, Goldin J, Lee HS, Strange C, McCormack FX; MILES Study Investigators.
RATIONALE: The Multicenter International Lymphangioleiomyomatosis Efficacy and Safety of Sirolimus (MILES) trial demonstrated that sirolimus stabilized lung function and improved measures of functional performance and quality of life in patients with lymphangioleiomyomatosis. The physiologic mechanisms of these beneficial actions of sirolimus are incompletely understood. OBJECTIVES: To prospectively determine the longitudinal computed tomographic lung imaging correlates of lung function change in MILES patients treated with placebo or sirolimus. METHODS: We determined the baseline to 12-month change in computed tomographic image-derived lung volumes and the volume of the lung occupied by cysts in the 31 MILES participants (17 in sirolimus group, 14 in placebo group) with baseline and 12-month scans.
March 2016Safety and Efficacy of Solitaire Stent Thrombectomy: Individual Patient Data Meta-Analysis of Randomized Trials.
Campbell BC, Hill MD, Rubiera M, Menon BK, Demchuk A, Donnan GA, Roy D, Thornton J, Dorado L, Bonafe A, Levy EI, Diener HC, Hernández-Pérez M, Pereira VM, Blasco J, Quesada H, Rempel J,Jahan R, Davis SM, Stouch BC, Mitchell PJ, Jovin TG, Saver JL, Goyal M.
BACKGROUND AND PURPOSE: Recent positive randomized trials of endovascular therapy for ischemic stroke used predominantly stent retrievers. We pooled data to investigate the efficacy and safety of stent thrombectomy using the Solitaire device in anterior circulation ischemic stroke. METHODS: Patient-level data were pooled from trials in which the Solitaire was the only or the predominant device used in a prespecified meta-analysis (SEER Collaboration): Solitaire FR With the Intention for Thrombectomy as Primary Endovascular Treatment (SWIFT PRIME), Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times (ESCAPE), Extending the Time for Thrombolysis in Emergency Neurological Deficits-Intra-Arterial (EXTEND-IA), and Randomized Trial of Revascularization With Solitaire FR Device Versus Best Medical Therapy in the Treatment of Acute Stroke Due to Anterior Circulation Large Vessel Occlusion Presenting Within Eight Hours of Symptom Onset (REVASCAT). The primary outcome was ordinal analysis of modified Rankin Score at 90 days. The primary analysis included all patients in the 4 trials with 2 sensitivity analyses: (1) excluding patients in whom Solitaire was not the first device used and (2) including the 3 Solitaire-only trials (excluding ESCAPE). Secondary outcomes included functional independence (modified Rankin Score 0-2), symptomatic intracerebral hemorrhage, and mortality.
March 2016Adverse Left Ventricular Remodeling and Age Assessed with Cardiac MR Imaging: The Multi-Ethnic Study of Atherosclerosis.
Eng J, McClelland RL, Gomes AS, Hundley WG, Cheng S, Wu CO, Carr JJ, Shea S, Bluemke DA, Lima JA.
PURPOSE: To evaluate age-related left ventricular (LV) remodeling during longitudinal observation of a large cohort of asymptomatic individuals who were free of clinical cardiovascular disease at baseline. MATERIAL AND METHODS: The applicable institutional review boards approved this study, and all participants gave informed consent. Cardiac magnetic resonance (MR) imaging was used to identify longitudinal changes in LV structure and function in 2935 participants who underwent baseline and follow-up cardiac MR imaging in the Multi-Ethnic Study of Atherosclerosis. Participants were free of clinical cardiovascular disease at baseline. Participants who experienced an incident coronary heart disease event were excluded. Data were analyzed with multivariable mixed-effects regression models in which the outcome was cardiac MR imaging measurement, and the covariates included follow-up time and cardiac risk factors.
March 2016Technical Note: FreeCT_wFBP: A Robust, Efficient, Open-source Implementation of Weighted Filtered Backprojection for Helical, Fan-beam CT.
Hoffman J, Young S, Noo F, McNitt-Gray M.
PURPOSE: With growing interest in quantitative imaging, radiomics, and CAD using CT imaging, the need to explore the impacts of acquisition and reconstruction parameters has grown. This usually requires extensive access to the scanner on which the data were acquired and its workflow is not designed for large-scale reconstruction projects. Therefore, the authors have developed a freely available, open-source software package implementing a common reconstruction method, weighted filtered backprojection (wFBP), for helical fan-beam CT applications. METHODS: FreeCT_wFBP is a low-dependency, GPU-based reconstruction program utilizing c for the host code and Nvidia CUDA C for GPU code. The software is capable of reconstructing helical scans acquired with arbitrary pitch-values, and sampling techniques such as flying focal spots and a quarter-detector offset. In this work, the software has been described and evaluated for reconstruction speed, image quality, and accuracy. Speed was evaluated based on acquisitions of the ACR CT accreditation phantom under four different flying focal spot configurations. Image quality was assessed using the same phantom by evaluating CT number accuracy, uniformity, and contrast to noise ratio (CNR). Finally, reconstructed mass-attenuation coefficient accuracy was evaluated using a simulated scan of a FORBILD thorax phantom and comparing reconstructed values to the known phantom values.
March 2016Rethinking the Role of Nitroglycerin Ointment in Ischemic Vascular Filler Complications: An Animal Model With ICG Imaging.
Hwang CJ, Morgan PV, Pimentel A, Sayre JW, Goldberg RA, Duckwiler G.
PURPOSE: Soft tissue dermal fillers, both temporary and permanent, are used frequently in facial rejuvenation. As the use of fillers increases, ischemic complications including skin necrosis are becoming more prevalent. In the literature, topical nitroglycerin paste has been recommended in the early treatment of patients presenting with ischemia. The purpose of this study was to evaluate the vascular perfusion effects of topical nitroglycerin paste in an animal model using indocyanine green (ICG) imaging. METHODS: After Animal Research Committee approval, a rabbit ear model was used to create filler-associated skin ischemia. Ischemia was confirmed to occur after intra-arterial occlusion. Four commonly used soft tissue fillers were injected intra-arterially: Radiesse (Merz USA, Greensboro NC), Restylane (Galderma, Ft. Worth, TX), Juvederm Ultra (Allergan, Irvine CA), Belotero (Merz USA, Greensboro NC) (0.1 ml). A total of 15 ears were used, 1 control and 4 experimental per product. Thirty minutes after occlusion, nitroglycerin ointment USP, 2%(Nitro-Bid) was applied topically to the experimental ears. Vascular perfusion was evaluated with the SPY System (Novadaq Inc.) using ICG imaging. Perfusion images were obtained at baseline, immediately after, and 30 minutes after intra-arterial filler injection, and at 30, 60, 90, and 120 minutes after application of topical nitroglycerin ointment.
March 20163D Spatially Encoded and Accelerated TE-averaged Echo Planar Spectroscopic Imaging in Healthy Human Brain.
Iqbal Z, Wilson NE, Thomas MA.
Several different pathologies, including many neurodegenerative disorders, affect the energy metabolism of the brain. Glutamate, a neurotransmitter in the brain, can be used as a biomarker to monitor these metabolic processes. One method that is capable of quantifying glutamate concentration reliably in several regions of the brain is TE-averaged (1) H spectroscopic imaging. However, this type of method requires the acquisition of multiple TE lines, resulting in long scan durations. The goal of this experiment was to use non-uniform sampling, compressed sensing reconstruction and an echo planar readout gradient to reduce the scan time by a factor of eight to acquire TE-averaged spectra in three spatial dimensions. Simulation of glutamate and glutamine showed that the 2.2-2.4 ppm spectral region contained 95% glutamate signal using the TE-averaged method. Peak integration of this spectral range and home-developed, prior-knowledge-based fitting were used for quantitation. Gray matter brain phantom measurements were acquired on a Siemens 3T Trio scanner. Non-uniform sampling was applied retrospectively to these phantom measurements and quantitative results of glutamate with respect to creatine 3.0 (Glu/Cr) ratios showed a coefficient of variance of 16% for peak integration and 9% for peak fitting using eight-fold acceleration. In vivo scans of the human brain were acquired as well and five different brain regions were quantified using the prior-knowledge-based algorithm. Glu/Cr ratios from these regions agreed with previously reported results in the literature. The method described here, called accelerated TE-averaged echo planar spectroscopic imaging (TEA-EPSI), is a significant methodological advancement and may be a useful tool for categorizing glutamate changes in pathologies where affected brain regions are not known a priori. Copyright © 2016 John Wiley & Sons, Ltd.
March 2016An Open Letter to the Food and Drug Administration Regarding the Use of Morcellation Procedures in Women Having Surgery for Presumed Uterine Myomas.
Parker W, Berek JS, Pritts E, Olive D, Kaunitz AM, Chalas E, Clarke-Pearson D, Goff B, Bristow R, Taylor HS, Farias-Eisner R, Fader AN, Maxwell GL, Goodwin SC, Love S, Gibbons WE, Foshag LJ, Leppert PC, Norsigian J, Nager CW, Johnson T, Guzick DS, As-Sanie S, Paulson RJ, Farquhar C, Bradley L, Scheib SA, Bilchik AJ, Rice LW, Dionne C, Jacoby A, Ascher-Walsh C, Kilpatrick SJ, Adamson GD, Siedhoff M, Israel R, Paraiso MF, Frumovitz MM, Lurain JR, Al-Hendy A, Benrubi GI, Raman SS, Kho RM, Anderson TL, Reynolds RK, DeLancey J.
In November, 2014 the Food and Drug Administration (FDA) ruled that power morcellation was contraindicated in "the majority of women" undergoing surgery for uterine myomas, owing to the potential risk of spreading occult uterine sarcoma. Although problems with this ruling were immediately apparent, the passage of time has allowed for more clarity on the related medical issues.
Pope WB, Djoukhadar I, Jackson A.
Imaging is integral to the management of patients with brain tumors. Conventional structural imaging provides exquisite anatomic detail but remains limited in the evaluation of molecular characteristics of intracranial neoplasms. Quantitative and physiologic biomarkers derived from advanced imaging techniques have been increasingly utilized as problem-solving tools to identify glioma grade and assess response to therapy. This chapter provides a comprehensive overview of the imaging strategies used in the clinical assessment of patients with gliomas and describes how novel imaging biomarkers have the potential to improve patient management.
March 2016The Evidence for Low-dose CT Screening of Lung Cancer.
Ruchalski K, Gutierrez A, Genshaft S, Abtin F, Suh R.
Lung cancer remains the leading cause of cancer-related death in the United States. An effective screening tool for early lung cancer detection has long been sought. Early chest radiograph and low-dose computed tomography (LDCT) screening trials were promising and demonstrated increased cancer detection. However, these studies were not able to improve lung cancer mortality. The National Lung Screening Trial resulted in decreased lung cancer mortality with LDCT screening in a high-risk population. Similar trials are currently underway in Europe. With LDCT now being widely implemented, it is paramount for radiologists to understand the evidence for lung cancer screening.
March 2016Misconnections in the Critically Ill: Injection of High-Dose Gadolinium into an External Ventricular Drain.
Singh S, Rejai S, Antongiorgi Z, Gonzalez N, Stelzner M.
We report an unfortunate case of accidental administration of intrathecal gadolinium through an external ventricular drain in a postcraniotomy patient during magnetic resonance imaging of the brain. The incident occurred after the venous contrast line was connected mistakenly to the ventricular drainage catheter. The patient subsequently developed confusion, aphasia, and right facial droop with new computed tomography evidence of diffuse cerebral edema and stroke. Review of the magnetic resonance image revealed the inappropriate presence of subarachnoid gadolinium. Despite all interventions, the patient developed irreversible neurologic disability. We address the clinical sequelae, management strategies, and factors contributing to the catheter misconnection that led to this event.
February 2016Evaluating Topic Model Interpretability from a Primary Care Physician Perspective.
Arnold CW, Oh A, Chen S, Speier W.
BACKGROUND AND OBJECTIVE: Probabilistic topic models provide an unsupervised method for analyzing unstructured text. These models discover semantically coherent combinations of words (topics) that could be integrated in a clinical automatic summarization system for primary care physicians performing chart review. However, the human interpretability of topics discovered from clinical reports is unknown. Our objective is to assess the coherence of topics and their ability to represent the contents of clinical reports from a primary care physician's point of view. METHODS: Three latent Dirichlet allocation models (50 topics, 100 topics, and 150 topics) were fit to a large collection of clinical reports. Topics were manually evaluated by primary care physicians and graduate students. Wilcoxon Signed-Rank Tests for Paired Samples were used to evaluate differences between different topic models, while differences in performance between students and primary care physicians (PCPs) were tested using Mann-Whitney U tests for each of the tasks.
February 2016Towards Use of MRI-guided Ultrasound for Treating Cerebral Vasospasm.
Bonow RH, Silber JR, Enzmann DR, Beauchamp NJ, Ellenbogen RG, Mourad PD.
Cerebral vasospasm is a major cause of morbidity and mortality in patients with subarachnoid hemorrhage (SAH), causing delayed neurological deficits in as many as one third of cases. Existing therapy targets induction of cerebral vasodilation through use of various drugs and mechanical means, with a range of observed efficacy. Here, we perform a literature review supporting our hypothesis that transcranially delivered ultrasound may have the ability to induce therapeutic cerebral vasodilation and, thus, may one day be used therapeutically in the context of SAH. Prior studies demonstrate that ultrasound can induce vasodilation in both normal and vasoconstricted blood vessels in peripheral tissues, leading to reduced ischemia and cell damage. Among the proposed mechanisms is alteration of several nitric oxide (NO) pathways, where NO is a known vasodilator. While in vivo studies do not point to a specific physical mechanism, results of in vitro studies favor cavitation induction by ultrasound, where the associated shear stresses likely induce NO production. Two papers discussed the effects of ultrasound on the cerebral vasculature. One study applied clinical transcranial Doppler ultrasound to a rodent complete middle cerebral artery occlusion model and found reduced infarct size. A second involved the application of pulsed ultrasound in vitro to murine brain endothelial cells and showed production of a variety of vasodilatory chemicals, including by-products of arachidonic acid metabolism. In sum, nine reviewed studies demonstrated evidence of either cerebrovascular dilation or elaboration of vasodilatory compounds. Of particular interest, all of the reviewed studies used ultrasound capable of transcranial application: pulsed ultrasound, with carrier frequencies ranging between 0.5 and 2.0 MHz, and intensities not substantially above FDA-approved intensity values. We close by discussing potential specific treatment paradigms of SAH and other cerebral ischemic disorders based on MRI-guided transcranial ultrasound.
February 2016The Impact of T2/FLAIR Evaluation per RANO Criteria on Response Assessment of Recurrent Glioblastoma Patients Treated with Bevacizumab.
Huang RY, Rahman R, Ballman KV, Felten SJ, Anderson SK, Ellingson BM, Nayak L, Lee EQ, Abrey LE, Galanis E, Reardon DA, Pope WB, Cloughesy TF, Wen PY.
PURPOSE: The RANO criteria have not been assessed using outcome data from prospective trials. We examined the radiologic data of patients with recurrent glioblastoma from the randomized phase II trial (AVF3708g) to determine the effect of including T2/FLAIR evaluation as per RANO criteria on measurements of objective response rates (ORRs) and progression-free survival (PFS) compared with assessment based on contrast enhancement (Macdonald criteria). EXPERIMENTAL DESIGN: The ORRs and median PFS were determined using the RANO criteria and compared with those obtained using the Macdonald criteria. Landmark analyses were performed at 2, 4, and 6 months, and Cox proportional hazard models were used to determine the associations between OR and progression with subsequent survival.
February 2016Matched Cohort Analysis of the Effects of Limb Remote Ischemic Conditioning in Patients with Aneurysmal Subarachnoid Hemorrhage.
Laiwalla AN, Ooi YC, Liou R, Gonzalez NR.
Remote ischemic conditioning (RIC) is a powerful innate response to transient subcritical ischemia that protects against severe ischemic insults at distant sites. We have previously shown the safety and feasibility of limb RIC in aneurysmal subarachnoid hemorrhage (aSAH) patients, along with changes in neurovascular and cerebral metabolism. In this study, we aim to detect the potential effect of an established lower-limb conditioning protocol on clinical outcomes of aSAH patients. Neurologic outcome (modified Rankin Scale (mRS)) of patients enrolled in a prospective trial (RIPC-SAH) was measured. A matching algorithm was applied to identify control patients with aSAH from an institutional departmental database. RIC patients underwent four lower-limb conditioning sessions, consisting of four 5-min cycles per session over nonconsecutive days. Good functional outcome was defined as mRS of 0 to 2. The study population consisted of 21 RIC patients and 61 matched controls. There was no significant intergroup difference in age, gender, aneurysm location, clipping vs coiling, Fisher grades, Hunt and Hess grades, or vasospasm. RIC was independently associated with good outcome (OR 5.17; 95 % confidence interval (CI) 1.21-25.02). RIC also showed a trend toward lower incidence of stroke (28.6 vs. 47.5 %) and death (4.8 vs. 19.7 %). Lower-limb RIC following aSAH appears to have a positive effect in the functional outcomes of patients with aSAH. While this effect is consistent with prior preclinical studies, future trials are necessary to conclusively evaluate the effects of RIC for aSAH.
February 2016Utilizing Time-driven Activity-based Costing to Understand the Short- and Long-term Costs of Treating Localized, Low-risk Prostate Cancer.
Laviana AA, Ilg AM, Veruttipong D, Tan HJ, Burke MA, Niedzwiecki DR, Kupelian PA, King CR, Steinberg ML, Kundavaram CR, Kamrava M, Kaplan AL, Moriarity AK, Hsu W, Margolis DJ, Hu JC, Saigal CS.
BACKGROUND: Given the costs of delivering care for men with prostate cancer remain poorly described, this article reports the results of time-driven activity-based costing (TDABC) for competing treatments of low-risk prostate cancer. METHODS: Process maps were developed for each phase of care from the initial urologic visit through 12 years of follow-up for robotic-assisted laparoscopic prostatectomy (RALP), cryotherapy, high-dose rate (HDR) and low-dose rate (LDR) brachytherapy, intensity-modulated radiation therapy (IMRT), stereotactic body radiation therapy (SBRT), and active surveillance (AS). The last modality incorporated both traditional transrectal ultrasound (TRUS) biopsy and multiparametric-MRI/TRUS fusion biopsy. The costs of materials, equipment, personnel, and space were calculated per unit of time and based on the relative proportion of capacity used. TDABC for each treatment was defined as the sum of its resources.
February 2016Effect of Endovascular Reperfusion in Relation to Site of Arterial Occlusion.
Lemmens R, Hamilton SA, Liebeskind DS, Tomsick TA, Demchuk AM, Nogueira RG, Marks MP,Jahan R, Gralla J, Yoo AJ, Yeatts SD, Palesch YY, Saver JL, Pereira VM, Broderick JP, Albers GW, Lansberg MG; DEFUSE 2, IMS III, STAR, and SWIFT trialists; DEFUSE 2 IMS III STAR and SWIFT trialists.
OBJECTIVE: To assess whether the association between reperfusion and improved clinical outcomes after stroke differs depending on the site of the arterial occlusive lesion (AOL). METHODS: We pooled data from Solitaire With the Intention for Thrombectomy (SWIFT), Solitaire FR Thrombectomy for Acute Revascularisation (STAR), Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution Study 2 (DEFUSE 2), and Interventional Management of Stroke Trial (IMS III) to compare the strength of the associations between reperfusion and clinical outcomes in patients with internal carotid artery (ICA), proximal middle cerebral artery (MCA) (M1), and distal MCA (M2/3/4) occlusions.
February 2016Two Cases of Rheumatoid Meningitis.
Magaki S, Chang E, Hammond RR, Yang I, Mackenzie IR, Chou BT, Choi SI, Jen JC, Pope WB, Bell DA, Vinters HV.
Central nervous system (CNS) involvement by rheumatoid arthritis (RA) in the form of rheumatoid meningitis (RM) is rare and most commonly occurs in the setting of longstanding severe RA. Due to a wide range of clinical presentations and nonspecific laboratory findings, it presents a diagnostic challenge often requiring brain biopsy. Only a few histopathologically confirmed cases have been described in the literature. Our aim is to describe two cases of RM and review the literature. The first case is of a previously healthy 37-year-old man who presented with severe headaches and focal neurologic deficits. Magnetic resonance imaging demonstrated abnormal leptomeningeal enhancement in the left frontal and parietal sulci. The second case is of a 62-year-old woman with a history of mild chronic joint pain who presented with confusion, personality changes and seizures. Both patients ultimately underwent brain biopsy which demonstrated RM on pathologic examination. Administration of corticosteroids resulted in significant clinical improvement in both cases. To our knowledge, our unusual case of RM in the young man is the fifth reported case of rheumatoid meningitis in a patient with no prior history of RA. Such an atypical presentation makes diagnosis even more difficult and highlights the need for awareness of this entity in the diagnostic consideration of a patient presenting with unexplained neurologic symptoms. Our literature review underscores the clinical and pathologic heterogeneity of CNS involvement in RA.
February 2016Successful Recanalization for Acute Ischemic Stroke via the Transbrachial Approach.
Okawa M, Tateshima S, Liebeskind D, Ali LK, Thompson ML, Saver J, Duckwiler GR.
The recent development of revascularization devices, including stent retrievers, has enabled increasingly higher revascularization rates for arterial occlusions in acute ischemic stroke. Patient-specific factors such as anatomy, however, may occasionally limit endovascular deployment of these new devices via the conventional transfemoral approach. We report three cases of acute ischemic stroke where a transbrachial endovascular approach to revascularization was used, resulting in successful recanalization. These examples suggest that a transbrachial approach may be considered as an alternative in the endovascular treatment of acute ischemic stroke.
February 2016Modified Wideband Three-dimensional Late Gadolinium Enhancement MRI for Patients with Implantable Cardiac Devices.
Rashid S, Rapacchi S, Shivkumar K, Plotnik A, Finn JP, Hu P.
PURPOSE: To study the effects of cardiac devices on three-dimensional (3D) late gadolinium enhancement (LGE) MRI and to develop a 3D LGE protocol for implantable cardioverter defibrillator (ICD) patients with reduced image artifacts. THEORY AND METHODS: The 3D LGE sequence was modified by implementing a wideband inversion pulse, which reduces hyperintensity artifacts, and by increasing bandwidth of the excitation pulse. The modified wideband 3D LGE sequence was tested in phantoms and evaluated in six volunteers and five patients with ICDs.
February 2016Predictors of Thrombotic Complications and Mass Effect Exacerbation After Pipeline Embolization: The Significance of Adenosine Diphosphate Inhibition, Fluoroscopy Time, and Aneurysm Size.
Raychev R, Tateshima S, Vinuela F, Sayre J, Jahan R, Gonzalez N, Szeder V, Duckwiler G.
BACKGROUND: The mechanisms leading to delayed rupture, distal emboli and intraparenchymal hemorrhage in relation to pipeline embolization device (PED) placement remain debatable and poorly understood. The aim of this study was to identify clinical and procedural predictors of these perioperative complications. METHODS: We conducted a retrospective review of consecutive patients who underwent PED placement. We utilized a non-commercial platelet aggregation method measuring adenosine diphosphate (ADP)% inhibition for evaluation of clopidogrel response. To our knowledge, this is the first study to test ADP in neurovascular procedures. Multivariable regression analysis was used to identify the strongest predictor of three separate outcomes: (1) thrombotic complications, (2) hemorrhagic complications, and (3) aneurysm mass effect exacerbation
February 2016Radiation-Induced Cataractogenesis: A Critical Literature Review for the Interventional Radiologist.
Seals KF, Lee EW, Cagnon CH, Al-Hakim RA, Kee ST.
Extensive research supports an association between radiation exposure and cataractogenesis. New data suggests that radiation-induced cataracts may form stochastically, without a threshold and at low radiation doses. We first review data linking cataractogenesis with interventional work. We then analyze the lens dose typical of various procedures, factors modulating dose, and predicted annual dosages. We conclude by critically evaluating the literature describing techniques for lens protection, finding that leaded eyeglasses may offer inadequate protection and exploring the available data on alternative strategies for cataract prevention.
February 2016Relationship Between Quantitative Radiographic Assessments of Interstitial Lung Disease and Physiological and Clinical Features of Systemic Sclerosis.
Tashkin DP, Volkmann ER, Tseng CH, Kim HJ, Goldin J, Clements P, Furst D, Khanna D, Kleerup E, Roth MD, Elashoff R.
OBJECTIVES: Extent of systemic sclerosis (SSc)-related interstitial lung disease (ILD) assessed from thoracic high-resolution CT (HRCT) predicts disease course, mortality and treatment response. While quantitative HRCT analyses of extent of lung fibrosis (QLFib) or total interstitial lung disease (QILD) are more sensitive and reproducible than visual HRCT assessments of SSc-ILD, these analyses are not widely available. This study evaluates the relationship between clinical disease parameters and QLFib and QILD scores to identify potential surrogate measures of radiographic extent of ILD. METHODS: Using baseline data from the Scleroderma Lung Study I (SLS I; N=158), multivariate regression analyses were performed using the best subset selection method to identify one to five variable models that best correlated with QLFib and QILD scores in both whole lung (WL) and the zone of maximal involvement (ZM). These models were subsequently validated using baseline data from SLS II (N=142). Bivariate analyses of the radiographic and clinical variables were also performed using pooled data. SLS I and II did not include patients with clinically significant pulmonary hypertension (PH).
January 2016MRI Suggests Increased Tonicity of the Levator Ani in Women with Interstitial Cystitis/bladder Pain Syndrome.
Ackerman AL, Lee UJ, Jellison FC, Tan N, Patel M, Raman SS, Rodriguez LV.
INTRODUCTION AND HYPOTHESIS: In interstitial cystitis/bladder pain syndrome (IC/BPS), pelvic floor dysfunction may contribute significantly to pelvic pain. To determine if pelvic floor hypertonicity manifests alterations on magnetic resonance imaging (MRI) in patients with IC/BPS, we retrospectively compared pelvic measurements between patients and controls. METHODS: Fifteen women with IC/BPS and 15 age-matched controls underwent pelvic MRI. Two blinded radiologists measured the pelvic musculature, including the H- and M lines, vaginal length, urethral length and cross-sectional area, levator width and length, and posterior puborectalis angle. MRI measures and clinical factors, such as age, parity, and duration of symptoms, were compared using a paired, two-tailed t test.
January 2016Ischemic Core and Hypoperfusion Volumes Predict Infarct Size in SWIFT PRIME.
Albers GW, Goyal M, Jahan R, Bonafe A, Diener HC, Levy EI, Pereira VM, Cognard C, Cohen DJ, Hacke W, Jansen O, Jovin TG, Mattle HP, Nogueira RG, Siddiqui AH, Yavagal DR, Baxter BW, Devlin TG, Lopes DK, Reddy VK, de Rochemont Rdu M, Singer OC, Bammer R, Saver JL.
OBJECTIVE: Within the context of a prospective randomized trial (SWIFT PRIME), we assessed whether early imaging of stroke patients, primarily with computed tomography (CT) perfusion, can estimate the size of the irreversibly injured ischemic core and the volume of critically hypoperfused tissue. We also evaluated the accuracy of ischemic core and hypoperfusion volumes for predicting infarct volume in patients with the target mismatch profile. METHODS: Baseline ischemic core and hypoperfusion volumes were assessed prior to randomized treatment with intravenous (IV) tissue plasminogen activator (tPA) alone versus IV tPA + endovascular therapy (Solitaire stent-retriever) using RAPID automated postprocessing software. Reperfusion was assessed with angiographic Thrombolysis in Cerebral Infarction scores at the end of the procedure (endovascular group) and Tmax > 6-second volumes at 27 hours (both groups). Infarct volume was assessed at 27 hours on noncontrast CT or magnetic resonance imaging (MRI).
January 2016Multisite, Multimodal Neuroimaging of Chronic Urological Pelvic Pain: Methodology of the MAPP Research Network.
Alger JR, Ellingson BM, Ashe-McNalley C, Woodworth DC, Labus JS, Farmer M, Huang L, Apkarian AV, Johnson KA, Mackey SC, Ness TJ, Deutsch G, Harris RE, Clauw DJ, Glover GH, Parrish TB, Hollander Jd, Kusek JW, Mullins C, Mayer EA; MAPP Research Network Investigators.
The Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network is an ongoing multi-center collaborative research group established to conduct integrated studies in participants with urologic chronic pelvic pain syndrome (UCPPS). The goal of these investigations is to provide new insights into the etiology, natural history, clinical, demographic and behavioral characteristics, search for new and evaluate candidate biomarkers, systematically test for contributions of infectious agents to symptoms, and conduct animal studies to understand underlying mechanisms for UCPPS. Study participants were enrolled in a one-year observational study and evaluated through a multisite, collaborative neuroimaging study to evaluate the association between UCPPS and brain structure and function. 3D T1-weighted structural images, resting-state fMRI, and high angular resolution diffusion MRI were acquired in five participating MAPP Network sites using 8 separate MRI hardware and software configurations. We describe the neuroimaging methods and procedures used to scan participants, the challenges encountered in obtaining data from multiple sites with different equipment/software, and our efforts to minimize site-to-site variation.
January 2016RadPath:: A Web-based System for Integrating and Correlating Radiology and Pathology Findings During Cancer Diagnosis.
Arnold CW, Wallace WD, Chen S, Oh A, Abtin F, Genshaft S, Binder S, Aberle D, Enzmann D.
RATIONALE AND OBJECTIVES: The current paradigm of cancer diagnosis involves uncoordinated communication of findings from radiology and pathology to downstream physicians. Discordance between these findings can require additional time from downstream users to resolve, or given incorrect resolution, may adversely impact treatment decisions. To mitigate this problem, we developed a web-based system, called RadPath, for correlating and integrating radiology and pathology reporting. MATERIALS AND METHODS: RadPath includes interfaces to our institution's clinical information systems, which are used to retrieve reports, images, and test results that are structured into an interactive compendium for a diagnostic patient case. The system includes an editing interface for physicians, allowing for the inclusion of additional clinical data, as well as the ability to retrospectively correlate and contextualize imaging findings following pathology diagnosis.
January 2016Synopsis of the PI-RADS v2 Guidelines for Multiparametric Prostate Magnetic Resonance Imaging and Recommendations for Use.
Barentsz JO, Weinreb JC, Verma S, Thoeny HC, Tempany CM, Shtern F, Padhani AR, Margolis D, Macura KJ, Haider MA, Cornud F, Choyke PL.
Rapid technical advances have enabled multiparametric magnetic resonance imaging (mpMRI) combined with magnetic resonance (MR)-targeted biopsy to become valuable tools for early detection of clinically significant prostate cancer (PCa) while reducing overdiagnosis of indolent PCa. There has been concern, however, that the widespread implementation and acceptance of mpMRI could be impaired by a lack of standardisation of image acquisition, interpretation and reporting guidance, and inter- and intraobserver variability that could result in poor clinical test performance in daily practise.
January 2016Contrast Enhancement Patterns after Irreversible Electroporation: Experimental Study of CT Perfusion Correlated to Histopathology in Normal Porcine Liver.
Chung DJ, Sung K, Osuagwu FC, Wu HH, Lassman C, Lu DS.
PURPOSE: To analyze ablated tissue zones after irreversible electroporation (IRE) of porcine liver using computed tomography (CT) perfusion imaging with histopathologic correlation. MATERIALS AND METHODS: Under ultrasound and CT guidance, 10 IRE ablations were performed percutaneously in three Yorkshire pigs using a single bipolar electrode. CT perfusion imaging was performed in all pigs immediately after ablation and on day 2. Pathologic sections were prepared for correlation with histopathology (hematoxylin-eosin and terminal deoxynucleotidyl transferase dUTP nick end labeling stains, 5-mm-thick slices). The short diameter of different enhancing zones on CT was correlated with the gross specimen.
January 2016Impact of Glucose on Outcomes in Patients Treated With Mechanical Thrombectomy: A Post Hoc Analysis of the Solitaire Flow Restoration With the Intention for Thrombectomy Study.
Kim JT, Jahan R, Saver JL; SWIFT Investigators.
BACKGROUND AND PURPOSE: Sparse data are available regarding the association between hyperglycemia and outcomes in acute ischemic stroke patients receiving mechanical thrombectomy (MT). We investigated whether hyperglycemia affected the outcomes of subjects treated with MT in the Solitaire Flow Restoration With the Intention for Thrombectomy (SWIFT) multicenter randomized trial, overall and according to reperfusion status after MT. METHODS: We analyzed the relationships between the presenting glucose level as a continuous variable and presenting hyperglycemia (>140 mg/dL glucose) as a binary variable and several outcomes of interest. Subjects were stratified according to the completeness of reperfusion (Thrombolysis In Myocardial Ischemia scale 3 versus 0-2) after MT. Excellent outcome at 3 months was defined as a modified Rankin scale score of 0-1.
January 2016Pain and Interoception Imaging Network (PAIN): A Multimodal, Multisite, Brain-imaging Repository for Chronic Somatic and Visceral Pain Disorders.
Labus JS, Naliboff B, Kilpatrick L, Liu C, Ashe-McNalley C, Dos Santos IR, Alaverdyan M, Woodworth D, Gupta A, Ellingson BM, Tillisch K, Mayer EA.
The Pain and Interoception Imaging Network (PAIN) repository (painrepository.org) is a newly created NIH (NIDA/NCCAM) funded neuroimaging data repository that aims to accelerate scientific discovery regarding brain mechanisms in pain and to provide more rapid benefits to pain patients through the harmonization of efforts and data sharing. The PAIN Repository consists of two components, an Archived Repository and a Standardized Repository. Similar to other 'open' imaging repositories, neuroimaging researchers can deposit any dataset of chronic pain patients and healthy controls into the Archived Repository. Scans in the Archived Repository can be very diverse in terms of scanning procedures and clinical metadata, complicating the merging of datasets for analyses. The Standardized Repository overcomes these limitations through the use of standardized scanning protocols along with a standardized set of clinical metadata, allowing an unprecedented ability to perform pooled analyses. The Archived Repository currently includes 741 scans and is rapidly growing. The Standardized Repository currently includes 433 scans. Pain conditions currently represented in the PAIN repository include: irritable bowel syndrome, vulvodynia, migraine, chronic back pain, and inflammatory bowel disease. Both the PAIN Archived and Standardized Repositories promise to be important resources in the field of chronic pain research. The enhanced ability of the Standardized Repository to combine imaging, clinical and other biological datasets from multiple sites in particular make it a unique resource for significant scientific discoveries.
January 2016Cost Analysis of Vestibular Schwannoma Screening with Contrast-enhanced Magnetic Resonance Imaging in Patients with Asymmetrical Hearing Loss.
Pan P, Huang J, Morioka C, Hathout G, El-Saden SM.
BACKGROUND: Vestibular schwannomas are a rare cause of asymmetrical hearing loss, and routine screening with magnetic resonance imaging can be costly. This paper reports results on vestibular schwannoma screening at our institution and compares the cost of screening to a utility of hearing benefit. METHOD: All screening examinations with magnetic resonance imaging performed for asymmetrical hearing loss between 2006 and 2011 were retrospectively reviewed. The cost per new vestibular schwannoma diagnosis was calculated. The cost per patient for those who benefitted from intervention was estimated based on rates of hearing preservation reported in the literature.
January 2016Collateral Flow as Causative of Good Outcomes in Endovascular Stroke Therapy.
Sheth SA, Sanossian N, Hao Q, Starkman S, Ali LK, Kim D, Gonzalez NR, Tateshima S, Jahan R, Duckwiler GR, Saver JL, Vinuela F, Liebeskind DS; UCLA Collateral Investigators.
BACKGROUND: Endovascular reperfusion techniques are a promising intervention for acute ischemic stroke (AIS). Prior studies have identified markers of initial injury (arrival NIH stroke scale (NIHSS) or infarct volume) as predictive of outcome after these procedures. We sought to define the role of collateral flow at the time of presentation in determining the extent of initial ischemic injury and its influence on final outcome. METHODS: Demographic, clinical, laboratory, and radiographic data were prospectively collected on a consecutive cohort of patients who received endovascular therapy for acute cerebral ischemia at a single tertiary referral center from September 2004 to August 2010.
January 2016Magnetic Resonance Imaging of Iron Oxide-Labeled Human Embryonic Stem Cell-Derived Cardiac Progenitors.
Skelton RJ, Khoja S, Almeida S, Rapacchi S, Han F, Engel J, Zhao P, Hu P, Stanley EG, Elefanty AG, Kwon M, Elliott DA, Ardehali R.
Given the limited regenerative capacity of the heart, cellular therapy with stem cell-derived cardiac cells could be a potential treatment for patients with heart disease. However, reliable imaging techniques to longitudinally assess engraftment of the transplanted cells are scant. To address this issue, we used ferumoxytol as a labeling agent of human embryonic stem cell-derived cardiac progenitor cells (hESC-CPCs) to facilitate tracking by magnetic resonance imaging (MRI) in a large animal model. Differentiating hESCs were exposed to ferumoxytol at different time points and varying concentrations. We determined that treatment with ferumoxytol at 300 μg/ml on day 0 of cardiac differentiation offered adequate cell viability and signal intensity for MRI detection without compromising further differentiation into definitive cardiac lineages. Labeled hESC-CPCs were transplanted by open surgical methods into the left ventricular free wall of uninjured pig hearts and imaged both ex vivo and in vivo. Comprehensive T2*-weighted images were obtained immediately after transplantation and 40 days later before termination. The localization and dispersion of labeled cells could be effectively imaged and tracked at days 0 and 40 by MRI. Thus, under the described conditions, ferumoxytol can be used as a long-term, differentiation-neutral cell-labeling agent to track transplanted hESC-CPCs in vivo using MRI.
January 2016Image-Guided Biopsy in the Era of Personalized Cancer Care: Proceedings from the Society of Interventional Radiology Research Consensus Panel.
Tam AL, Lim HJ, Wistuba II, Tamrazi A, Kuo MD, Ziv E, Wong S, Shih AJ, Webster RJ 3rd, Fischer GS, Nagrath S, Davis SE, White SB, Ahrar K.
Image-guided percutaneous biopsy is a common procedure in oncology that is integral in confirming the diagnosis of cancer, staging the disease, and determining tumor histology. However, in the era of personalized medicine, in which advances in knowledge of specific cellular pathways and characterization of tissue at molecular and genetic levels has resulted in an increase in targeted therapies, the role of the image-guided percutaneous biopsy is evolving. Biopsy samples are required for more than just histologic diagnosis, as biomarker status now guides standard-of-care therapy in a growing number of solid tumors including melanoma, breast, colon, and lung cancers. In addition, biopsies are no longer being performed only at the time of initial diagnosis, but are being performed at multiple time points to detect progression, predict prognosis, and guide next-line therapy. Image-guided biopsies are also playing an increasing role in oncologic clinical trials, as the US Food and Drug Administration (FDA) has mandated that targeted therapies be accompanied by a companion diagnostic test for appropriate patient selection. The research biopsy is so critical to clinical trial design that many stakeholders share the sentiment that the absence of high-quality biologic specimens is one of the most significant roadblocks to developing and validating biomarkers for their intended use. Finally, prioritizing the actualization of personalized cancer care in the United States was brought to the forefront by President Obama in his 2015 State of the Union address, in which he announced the Precision Medicine Initiative, which should "bring us closer to curing diseases like cancer."
January 2016Hypopharyngeal Venous Malformation Presenting with Foreign Body Sensation and Dysphagia.
Vahabzadeh-Hagh AM, Sepahdari AR, Fitter J, Abemayor E.
OBJECTIVE: Review the importance of imaging selection and clinicoanatomic correlation for a vascular malformations presenting with unique symptomatology. METHODS: Case study and literature review.
January 2016PI-RADS Prostate Imaging - Reporting and Data System: 2015, Version 2.
Weinreb JC, Barentsz JO, Choyke PL, Cornud F, Haider MA, Macura KJ, Margolis D, Schnall MD, Shtern F, Tempany CM, Thoeny HC, Verma S.
The Prostate Imaging - Reporting and Data System Version 2 (PI-RADS™ v2) is the product of an international collaboration of the American College of Radiology (ACR), European Society of Uroradiology (ESUR), and AdMetech Foundation. It is designed to promote global standardization and diminish variation in the acquisition, interpretation, and reporting of prostate multiparametric magnetic resonance imaging (mpMRI) examination, and it is based on the best available evidence and expert consensus opinion. It establishes minimum acceptable technical parameters for prostate mpMRI, simplifies and standardizes terminology and content of reports, and provides assessment categories that summarize levels of suspicion or risk of clinically significant prostate cancer that can be used to assist selection of patients for biopsies and management. It is intended to be used in routine clinical practice and also to facilitate data collection and outcome monitoring for research.
January 2016High-Resolution 3-T Endorectal Prostate MRI: A Multireader Study of Radiologist Preference and Perceived Interpretive Quality of 2D and 3D T2-Weighted Fast Spin-Echo MR Images.
Westphalen AC, Noworolski SM, Harisinghani M, Jhaveri KS, Raman SS, Rosenkrantz AB, Wang ZJ, Zagoria RJ, Kurhanewicz J.
OBJECTIVE: The goal of this study was to compare the perceived quality of 3-T axial T2-weighted high-resolution 2D and high-resolution 3D fast spin-echo (FSE) endorectal MR images of the prostate. MATERIALS AND METHODS: Six radiologists independently reviewed paired 3-T axial T2-weighted high-resolution 2D and 3D FSE endorectal MR images of the prostates of 85 men in two sessions. In the first session (n = 85), each reader selected his or her preferred images; in the second session (n = 28), they determined their confidence in tumor identification and compared the depiction of the prostatic anatomy, tumor conspicuity, and subjective intrinsic image quality of images. A meta-analysis using a random-effects model, logistic regression, and the paired Wilcoxon rank-sum test were used for statistical analyses.
January 2016Accelerated Five-dimensional Echo Planar J-resolved Spectroscopic Imaging: Implementation and Pilot Validation in Human Brain.
Wilson NE, Iqbal Z, Burns BL, Keller M, Thomas MA.
PURPOSE: To implement an accelerated five-dimensional (5D) echo-planar J-resolved spectroscopic imaging sequence combining 3 spatial and 2 spectral encoding dimensions and to apply the sequence in human brain. METHODS: An echo planar readout was used to acquire a single spatial and a single spectral dimension during one readout. Nonuniform sampling was applied to the two phase-encoded spatial directions and the indirect spectral dimension. Nonlinear reconstruction was used to minimize the ℓ1-norm or the total variation and included a spectral mask to enhance sparsity. Retrospective reconstructions at multiple undersamplings were performed in phantom. Ten healthy volunteers were scanned with 8x undersampling and compared to a fully sampled single slice scan.