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Research Publications


April 2016

Saving 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!' [1]


April 2016

Topographical 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 2016

Endovascular 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 2016

A 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 2016

Usefulness 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 2016

Microwave Ablation of Liver Tumors: Degree of Tissue Contraction as Compared to RF Ablation.

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 2016

Renal 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 2016

Physiologic 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 2016

Qualitative 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 2016

Treatments 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 2016

Supranormal 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 2016

A 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 2016

Safety 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 2016

Adverse 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 2016

Technical 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 2016

Rethinking 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 2016

3D 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 2016

An 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.


March 2016

Neuroimaging.

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 2016

The 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 2016

Misconnections 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 2016

Evaluating 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 2016

Towards 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 2016

The 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 2016

Matched 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 2016

Utilizing 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 2016

Effect 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 2016

Two 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 2016

Successful 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 2016

Modified 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 2016

Predictors 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 2016

Radiation-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 2016

Relationship 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 2016

MRI 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 2016

Ischemic 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 2016

RadPath:: 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 2016

Synopsis 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 2016

Contrast 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 2016

Impact 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 2016

Pain 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 2016

Cost 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 2016

Collateral 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 2016

Magnetic 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 2016

Image-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 2016

Hypopharyngeal 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 2016

PI-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 2016

High-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 2016

Accelerated 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.


January 2016

Hypopharyngeal Venous Malformation Presenting with Foreign Body Sensation and Dysphagia.

Vahabzadeh-Hagh AM, Sepahdari AR, Fitter J, Abemayor E.

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.


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