February 2018Cardiac Magnetic Resonance Imaging Using Wideband Sequences in Patients with Nonconditional Cardiac Implanted Electronic Devices.
Do DH, Eyvazian V, Bayoneta AJ, Hu P, Finn JP, Bradfield JS, Shivkumar K, Boyle NG.
BACKGROUND: Magnetic resonance imaging (MRI) has been performed safely in patients without MRI-conditional cardiac implantable electronic devices (CIEDs), but experience specifically with cardiac magnetic resonance imaging (CMR) is limited in this patient population. OBJECTIVE: Evaluate the safety of CMR in non-MRI-conditional CIEDs and the interpretability of images using wideband sequences. METHODS: We performed 114 consecutive CMR studies in 111 patients (mean age 59 ± 14 years, with 12 pacemakers, 73 implantable cardioverter defibrillators, 29 biventricular defibrillators) using a wideband pulse sequence for late gadolinium enhancement (LGE) imaging. A standardized protocol for device management and patient monitoring was followed. Patients were evaluated for major clinical adverse events and device parameter changes immediately after CMR and at clinical follow-up.
February 2018Diagnostic Criteria for Idiopathic Pulmonary Fibrosis: a Fleischner Society White Paper.
Lynch DA, Sverzellati N, Travis WD, Brown KK, Colby TV, Galvin JR, Goldin JG, Hansell DM, Inoue Y, Johkoh T, Nicholson AG, Knight SL, Raoof S, Richeldi L, Ryerson CJ, Ryu JH, Wells AU.
This Review provides an updated approach to the diagnosis of idiopathic pulmonary fibrosis (IPF), based on a systematic search of the medical literature and the expert opinion of members of the Fleischner Society. A checklist is provided for the clinical evaluation of patients with suspected usual interstitial pneumonia (UIP). The role of CT is expanded to permit diagnosis of IPF without surgical lung biopsy in select cases when CT shows a probable UIP pattern. Additional investigations, including surgical lung biopsy, should be considered in patients with either clinical or CT findings that are indeterminate for IPF. A multidisciplinary approach is particularly important when deciding to perform additional diagnostic assessments, integrating biopsy results with clinical and CT features, and establishing a working diagnosis of IPF if lung tissue is not available. A working diagnosis of IPF should be reviewed at regular intervals since the diagnosis might change. Criteria are presented to establish confident and working diagnoses of IPF.
February 2018A Structured Global Health Training Program for Radiology Residents.
Pool KL, Culp MP, Mollura DJ, Suh R.
The World Health Organization (WHO) increasingly recognizes the need and utility for quality diagnostic tests. Historically, imaging has played a key role for diagnosis and treatment plans for global health infectious diseases, like tuberculosis and human immunovirus (HIV) and acquired immunodeficiency syndrome. However, according to the WHO, there is a global rise in noncommunicable diseases, such as cancer and cardiovascular diseases, for which imaging has been an integral part of care in areas of high access to health care for decades . In analysis of WHO member states, a wide gap is shown between nations that have imaging and related treatment services and those that have minimal to no access . This background supports the increasing trend for radiology to be part of global health initiatives and underscores the dire need for medical imaging services in areas that currently lack access and human capacity ...
February 2018Investigating the Minimum Scan Parameters Required to Generate Free-breathing Motion Artefact-free Fast-helical CT.
Thomas DH, Tan J, Neylon J, Dou T, O'Connell D, McNitt-Gray M, Lee P, Lamb J, Low DA.
OBJECTIVE: A recently proposed "5DCT" protocol uses deformable registration of free-breathing fast-helical CT scans to generate a breathing motion model. In order to allow accurate registration, free-breathing images are required to be free of doubling-artefacts, which arise when tissue motion is greater than scan speed. METHODS: Using a unique set of digital phantoms based on patient data and verified with a motion phantom, this work identifies the minimum scanner parameters required to successfully generate free-breathing artefact-free fast-helical scans. A motion phantom and 5 patients were imaged 25 times under free-breathing conditions in alternating directions with a 64-slice CT scanner employing a low-dose fast-helical protocol. A series of high temporal resolution (0.1 s) 5DCT scan data sets was generated in each case. A simulated CT scanner was used to "image" each free-breathing data set. Various CT scanner detector widths and rotation times were simulated, and verified using the motion phantom results. Motion-induced artefacts were quantified in patient images using structural similarity maps to determine the similarity between axial slices.
January 2018Quantitative Bone Scan Lesion Area as an Early Surrogate Outcome Measure Indicative of Overall Survival in Metastatic Prostate Cancer.
Brown MS, Kim GHJ, Chu GH, Ramakrishna B, Allen-Auerbach M, Fischer CP, Levine B, Gupta PK, Schiepers CW, Goldin JG.
A clinical validation of the bone scan lesion area (BSLA) as a quantitative imaging biomarker was performed in metastatic castration-resistant prostate cancer (mCRPC). BSLA was computed from whole-body bone scintigraphy at baseline and week 12 posttreatment in a cohort of 198 mCRPC subjects (127 treated and 71 placebo) from a clinical trial involving a different drug from the initial biomarker development. BSLA computation involved automated image normalization, lesion segmentation, and summation of the total area of segmented lesions on bone scan AP and PA views as a measure of tumor burden. As a predictive biomarker, treated subjects with baseline BSLA [Formula: see text] had longer survival than those with higher BSLA ([Formula: see text] and [Formula: see text]). As a surrogate outcome biomarker, subjects were categorized as progressive disease (PD) if the BSLA increased by a prespecified 30% or more from baseline to week 12 and non-PD otherwise. Overall survival rates between PD and non-PD groups were statistically different ([Formula: see text] and [Formula: see text]). Subjects without PD at week 12 had longer survival than subjects with PD: median 398 days versus 280 days. BSLA has now been demonstrated to be an early surrogate outcome for overall survival in different prostate cancer drug treatments.
January 2018Improved Spatiotemporal Resolution of Dynamic Susceptibility Contrast Perfusion MRI in Brain Tumors Using Simultaneous Multi-Slice Echo-Planar Imaging.
Chakhoyan A, Leu K, Pope WB, Cloughesy TF, Ellingson BM.
DSC perfusion MR imaging in brain tumors requires a trade-off between spatial and temporal resolution, resulting in less spatial coverage to meet the temporal resolution requirements for accurate relative CBV estimation. DSC-MR imaging could potentially benefit from the advantages associated with simultaneous multi-slice imaging, including increased spatiotemporal resolution. In the current article, we demonstrate how simultaneous multi-slice EPI can be used to improve DSC-MR imaging spatiotemporal resolution in patients with glioblastoma.
January 2018Evaluating Casama: Contextualized Semantic Maps for Summarization of Lung Cancer Studies.
Garcia-Gathright JI, Matiasz NJ, Adame C, Sarma KV, Sauer L, Smedley NF, Spiegel ML, Strunck J, Garon EB, Taira RK, Aberle DR, Bui AAT.
OBJECTIVE: It is crucial for clinicians to stay up to date on current literature in order to apply recent evidence to clinical decision making. Automatic summarization systems can help clinicians quickly view an aggregated summary of literature on a topic. Casama, a representation and summarization system based on "contextualized semantic maps," captures the findings of biomedical studies as well as the contexts associated with patient population and study design. This paper presents a user-oriented evaluation of Casama in comparison to a context-free representation, SemRep. MATERIALS AND METHODS: The effectiveness of the representation was evaluated by presenting users with manually annotated Casama and SemRep summaries of ten articles on driver mutations in cancer. Automatic annotations were evaluated on a collection of articles on EGFR mutation in lung cancer. Seven users completed a questionnaire rating the summarization quality for various topics and applications.
January 2018Nature's Wastebasket: The Role of the External Carotid Artery in Acute Stroke.
Jones J, Liang CW, Ramezan-Arab N, Duckwiler G, Tateshima S.
We describe a novel technical approach to acute stroke illustrated by the case of a 41 year old male who presented with tandem right common carotid artery (CCA) and M1 occlusions. His NIHSS was 17 and Alberta stroke programe early CT score (ASPECTs) was 8. Thrombectomy initially proved challenging due to large volume CCA thrombus that repeatedly occluded the aspiration catheters. However, by inflating a balloon distally and pulling clot into the adjacent ECA, we were able to quickly restore distal contrast flow to the intracranial circulation and achieve Thrombolysis In Cerebral Infarction/Arterial Occlusive Lesion (TICI2C/AOL3) revascularization.
January 2018Low-dose CT Perfusion with Projection View Sharing.
Martin T, Hoffman J, Alger JR, McNitt-Gray M, Wang DJ.
PURPOSE: CT Perfusion (CTP) is a widely used clinical imaging modality. However, CTP typically involves the use of substantial radiation dose (CTDIvol ≥~200 mGy). The purpose of this study is to present a low-dose CTP technique using a projection view-sharing reconstruction algorithm originally developed for dynamic MRI - "K-space Weighted Image Contrast" (KWIC). METHODS: The KWIC reconstruction is based on an angle-bisection scheme. In KWIC, a Fourier transform was performed along each projection to form a "k-space"-like CT data space, based on the central-slice theorem. As a projection view-sharing technique, KWIC preserves the spatiotemporal resolution of undersampled CTP data by progressively increasing the number of projection views shared for more distant regions of "k-space". KWIC reconstruction was evaluated on a digital FORBILD head phantom with numerically simulated time-varying objects. The numerically simulated scans were undersampled using the angle-bisection scheme to achieve 50%, 25%, and 12.5% of the original dose (288, 144, and 72 projections, respectively). The area-under-the-curve (AUC), time-to-peak (TTP), and full width half maximum (FWHM) were measured in KWIC recons and compared to fully sampled filtered back projection (FBP) reconstructions. KWIC reconstruction and dose reduction was also implemented for three clinical CTP cases (45 s, 1156 projections per turn, 1 s/turn, CTDIvol 217 mGy). Quantitative perfusion metrics were computed and compared between KWIC reconstructed CTP data and those of standard FBP reconstruction.
January 2018High Resolution Three-Dimensional Delayed Contrast MRI Detects Endolymphatic Hydrops in Patients With Vertigo and Vestibular Schwannoma.
Moayer R, Ishiyama GP, Karnezis S, Sepahdari AR, Ishiyama A.
OBJECTIVE: Advances in high resolution magnetic resonance imaging (MRI) have enabled the detection of endolymphatic hydrops (EH), a pathological ballooning of the endolymphatic fluid system, known to be associated with Menière's disease. When a patient has a known diagnosis of vestibular schwannoma and develops recurrent episodic vertigo spells, many surgeons recommend surgical intervention, attributing the vestibular symptoms to the vestibular schwannoma. The aim of this study is to evaluate the clinical outcome in patients with vestibular schwannoma and EH, treated medically, for recurrent spells of vertigo. PATIENTS: Two patients with EH and vestibular schwannoma who presented with recurrent spells of vertigo are included. Both had characteristic low frequency hearing loss ipsilateral to the schwannoma. INTERVENTION: MRI sequences with 3T scanner (Skyra, Siemens Healthcare, Erlangen, Germany) using high resolution three-dimensional delayed postcontrast protocol included "cisternographic" T2 and delayed intravenous-enhanced three-dimensional fluid-attenuation inversion recovery (DIVE-3D-FLAIR) sequences, performed with 2350ms (bright perilymph) and 2050ms (bright endolymph) inversion times and with subtracted images.
January 2018Ferumoxytol-enhanced MR Angiography for Vascular Access Mapping before Transcatheter Aortic Valve Replacement in Patients with Renal Impairment: A Step Toward Patient-specific Care.
Nguyen KL, Moriarty JM, Plotnik AN, Aksoy O, Yoshida T, Shemin RJ, Suh WM, Finn JP.
PURPOSE: To assess the technical feasibility of the use of ferumoxytol-enhanced (FE) magnetic resonance (MR) angiography for vascular mapping before transcatheter aortic valve replacement in patients with renal impairment. MATERIALS AND METHODS: This was an institutional review board-approved and HIPAA-compliant study. FE MR angiography was performed at 3.0 T or 1.5 T. Unenhanced computed tomographic (CT) images were used to overlay vascular calcification on FE MR angiographic images as composite fused three-dimensional data. Image quality of the subclavian and aortoiliofemoral arterial tree and confidence in the assessment of calcification were evaluated by using a four-point scale (4 = excellent vascular definition or strong confidence). Signal intensity nonuniformity as reflected by the heterogeneity index (ratio between the mean standard deviation of luminal signal intensity and the mean luminal signal intensity), signal-to-noise ratio, and consistency of luminal diameter measurements were quantified. Findings at FE MR angiography were compared with pelvic angiograms.
January 2018Brain Metastases: Neuroimaging.
Magnetic resonance imaging (MRI) is the cornerstone for evaluating patients with brain masses such as primary and metastatic tumors. Important challenges in effectively detecting and diagnosing brain metastases and in accurately characterizing their subsequent response to treatment remain. These difficulties include discriminating metastases from potential mimics such as primary brain tumors and infection, detecting small metastases, and differentiating treatment response from tumor recurrence and progression. Optimal patient management could be benefited by improved and well-validated prognostic and predictive imaging markers, as well as early response markers to identify successful treatment prior to changes in tumor size. To address these fundamental needs, newer MRI techniques including diffusion and perfusion imaging, MR spectroscopy, and positron emission tomography (PET) tracers beyond traditionally used 18-fluorodeoxyglucose are the subject of extensive ongoing investigations, with several promising avenues of added value already identified. These newer techniques provide a wealth of physiologic and metabolic information that may supplement standard MR evaluation, by providing the ability to monitor and characterize cellularity, angiogenesis, perfusion, pH, hypoxia, metabolite concentrations, and other critical features of malignancy. This chapter reviews standard and advanced imaging of brain metastases provided by computed tomography, MRI, and amino acid PET, focusing on potential biomarkers that can serve as problem-solving tools in the clinical management of patients with brain metastases.
January 2018Myeloablative Autologous Stem-Cell Transplantation for Severe Scleroderma.
Sullivan KM, Goldmuntz EA, Keyes-Elstein L, McSweeney PA, Pinckney A, Welch B, Mayes MD, Nash RA, Crofford LJ, Eggleston B, Castina S, Griffith LM, Goldstein JS, Wallace D, Craciunescu O, Khanna D, Folz RJ, Goldin J, St Clair EW, Seibold JR, Phillips K, Mineishi S, Simms RW, Ballen K, Wener MH, Georges GE, Heimfeld S, Hosing C, Forman S, Kafaja S, Silver RM, Griffing L, Storek J, LeClercq S, Brasington R, Csuka ME, Bredeson C, Keever-Taylor C, Domsic RT, Kahaleh MB, Medsger T, Furst DE; SCOT Study Investigators.
BACKGROUND: Despite current therapies, diffuse cutaneous systemic sclerosis (scleroderma) often has a devastating outcome. We compared myeloablative CD34+ selected autologous hematopoietic stem-cell transplantation with immunosuppression by means of 12 monthly infusions of cyclophosphamide in patients with scleroderma. METHODS: We randomly assigned adults (18 to 69 years of age) with severe scleroderma to undergo myeloablative autologous stem-cell transplantation (36 participants) or to receive cyclophosphamide (39 participants). The primary end point was a global rank composite score comparing participants with each other on the basis of a hierarchy of disease features assessed at 54 months: death, event-free survival (survival without respiratory, renal, or cardiac failure), forced vital capacity, the score on the Disability Index of the Health Assessment Questionnaire, and the modified Rodnan skin score.
January 2018Visual Aids for Patient, Family, and Physician Decision Making About Endovascular Thrombectomy for Acute Ischemic Stroke.
Tokunboh I, Vales Montero M, Zopelaro Almeida MF, Sharma L, Starkman S, Szeder V, Jahan R, Liebeskind D, Gonzalez N, Demchuk A, Froehler MT, Goyal M, Lansberg MG, Lutsep H, Schwamm L, Saver JL.
BACKGROUND AND PURPOSE: Rapid decision making optimizes outcomes from endovascular thrombectomy for acute cerebral ischemia. Visual displays facilitate swift review of potential outcomes and can accelerate decision processes. METHODS: From patient-level, pooled randomized trial data, 100 person-icon arrays (Kuiper-Marshall personographs) were generated showing beneficial and adverse effects of endovascular thrombectomy for patients with acute cerebral ischemia and large vessel occlusion using (1) automated (algorithmic) and (2) expert-guided joint outcome table specification.
January 2018Lung Cancer Radiogenomics: The Increasing Value of Imaging in Personalized Management of Lung Cancer Patients.
Vardhanabhuti V, Kuo MD.
Radiogenomics provide a large-scale data analytical framework that aims to understand the broad multiscale relationships between the complex information encoded in medical images (including computational, quantitative, and semantic image features) and their underlying clinical, therapeutic, and biological associations. As such it is a powerful and increasingly important tool for both clinicians and researchers involved in the imaging, evaluation, understanding, and management of lung cancers. Herein we provide an overview of the growing field of lung cancer radiogenomics and its applications.