Skip to main content

Posts

Showing posts with the label Nradio

Journal Scan – This Month in Other Journals, November 2020

http://traffic.libsyn.com/ajnrpodcast/November2020AB.mp3 1. Salem MM, Ravindran K, Enriquez-Marulanda A, et al. Pipeline embolization device versus stent-assisted coiling for intracranial aneurysm treatment: a retrospective propensity score-matched study. Neurosurgery 2020;87:516–22 No studies have been done using propensity score to match small unruptured anterior circulation aneurysms (<10 mm), where controversy regarding the most appropriate treatment method exists. The aim of this study was to comparatively assess the efficacy of the Pipeline embolization device (PED) and stent-assisted coiling (SAC) via propensity score matching (PSM) in aneurysms deemed amenable to both modalities, controlling for both baseline and aneurysm characteristics. The authors conducted a retrospective analysis of patients with aneurysms treated at their institution with either PED from 2013 to 2017 or SAC from 2009 to 2015. All large (>10 mm), ruptured, fusiform, anterior communicating artery,

Imaging Features of Acute Encephalopathy in Patients with COVID-19: A Case Series

Fellows’ Journal Club The authors present 5 cases that illustrate varying imaging presentations of acute encephalopathy in patients with coronavirus disease 2019. MR features include leukoencephalopathy, diffusion restriction that involves the GM and WM, microhemorrhages, and leptomeningitis. Summary An axial MR imaging of the brain of a 60-year-old man with COVID-19 who presented with disorientation and decreased alertness (case 2). A , A FLAIR image demonstrates diffuse confluent WM hyperintensity with sparing of the subcortical U-fibers ( arrowheads ). B , DWI shows corresponding restricted diffusion throughout the involved WM ( arrowheads ). Coronavirus disease 2019 was declared a global pandemic by the World Health Organization on March 11, 2020. There is a scarcity of data on coronavirus disease 2019–related brain imaging features. We present 5 cases that illustrate varying imaging presentations of acute encephalopathy in patients with coronavirus disease 2019. MR feat

Tentorial Venous Anatomy: Variation in the Healthy Population

Editor’s Choice The authors retrospectively reviewed tentorial venous anatomy of the head using CTA/CTV performed for routine care or research purposes in 238 patients. Tentorial vein development was related to the ring configuration of the tentorial sinuses. There were 3 configurations: Groups 1A and 1B had ring configuration, while group 2 did not. Group 1A had a medialized ring configuration, and group 1B had a lateralized ring configuration. Measurements of skull base development were predictive of these groups. The ring configuration of group 1 was related to the presence of a split confluens, which correlated with a decreased internal auditory canal-petroclival fissure angle. Configuration 1A was related to the degree of petrous apex pneumatization. Abstract BACKGROUND AND PURPOSE Transtentorial veins. A–C , 3D volumetric reconstruction of delayed-phase CTA of the head and neck; parenchyma (0–40 HU) has been segmented out, leaving the intracranial vessels filled with co

Presurgical Identification of Primary Central Nervous System Lymphoma with Normalized Time-Intensity Curve: A Pilot Study of a New Method to Analyze DSC-PWI

Editor’s Choice The aims of this study were to: 1) to design a new method of postprocessing time-intensity curves, which renders normalized curves, and 2) to test its feasibility and performance on the diagnosis of primary central nervous system lymphoma. Time-intensity curves of enhancing tumor and normal-appearing white matter were obtained for each case. Enhancing tumor time-intensity curves were normalized relative to normal-appearing white matter. The authors performed pair-wise comparisons for primary central nervous system lymphoma against the other tumor type. The best discriminatory time points of the curves were obtained through a stepwise selection. Logistic binary regression was applied to obtain prediction models. A total of 233 patients were included in the study with 47 primary central nervous system lymphomas, 48 glioblastomas, 39 anaplastic astrocytomas, 49 metastases, and 50 meningiomas. The classifiers satisfactorily performed all bilateral comparisons in the test

Clinical and Neuroimaging Correlation in Patients with COVID-19

Fellows’ Journal Club This was a retrospective study performed at a large academic hospital in the United States. A total of 641 patients presented to the authors’ institution between March 3, 2020 and May 6, 2020, for treatment of coronavirus disease 2019, of whom, 150 underwent CT and/or MR imaging of the brain. CT and/or MR imaging examinations were evaluated for the presence of hemorrhage, infarction, and leukoencephalopathy. Of the 150 patients, 26 (17%) had abnormal CT and/or MR imaging findings, with hemorrhage in 11 of the patients (42%), infarction in 13 of the patients (50%), and leukoencephalopathy in 7 of the patients (27%). Significant associations were seen between abnormal CT/MR imaging findings and intensive care unit admission, intubation, and acute kidney injury. Abstract Examples of intracranial hemorrhages in patients with COVID-19. A , An axial noncontrast CT of a 42-year-old man demonstrates an acute intraparenchymal hematoma in the right cerebellar hemis

Neuroimaging Clinics of North America: State of the Art Evaluation of the Head and Neck

Srinivasan A, ed. Mukherji SK, consulting ed. Neuroimaging Clinics of North America: State of the Art Evaluation of the Head and Neck . Elsevier; 2020;30(3):261–392; $397.00 Coming nearly in a coordinated fashion with the just-ended virtual American Society of Head and Neck Radiology Annual Meeting, the current issue of Neuroimaging Clinics develops a number of themes that are pertinent to the practice of head and neck radiology or will soon become incorporated into interpretation and reporting of head and neck cases. Edited by Dr. Ashok Srinivasan from the University of Michigan and authored/co-authored by 33 contributors, there are 9 chapters, which delve into some of the major areas of imaging of the head and neck. After a review of the general principles of DWI, the chapter on diffusion MR imaging shows, with good examples, how DWI can be useful in differential diagnosis, and more importantly, how separation of some malignant versus benign lesions can be suggested by findings o

Journal Scan – This Month in Other Journals, October 2020

http://traffic.libsyn.com/ajnrpodcast/October2020AB.mp3 1. Dea N, Versteeg AL, Sahgal A, et al. Metastatic spine disease: should patients with short life expectancy be denied surgical care? An international retrospective cohort study. Neurosurgery 2020;87(2):303–11 Recent advances in medical oncology, especially with targeted molecular treatment, have resulted in patients with metastatic spine disease and a seemingly dismal prognosis living longer and challenging traditional surgical decision-making. This coupled with breakthroughs in radiation and surgical technology, particularly separation surgery, has left the oncologist and surgeon alike with more treatment options to maintain or improve health-related quality of life (HRQOL), but with little guidance to apply them. Historically, the essential prerequisite to any surgical indication for patients with metastatic disease to the spine was to have an expected survival of at least 3 mo. This surgical requirement comes from the prem

Focal Areas of High Signal Intensity in Children with Neurofibromatosis Type 1: Expected Evolution on MRI

Fellows’ Journal Club The authors retrospectively examined the MRI of children diagnosed with neurofibromatosis type 1 using the National Institutes of Health Consensus Criteria (1987), with imaging follow-up of at least 4 years. They recorded the number, size, and surface area of focal areas of high signal intensity according to their anatomic distribution on T2WI/T2-FLAIR sequences. A generalized mixed model was used to analyze the evolution of focal areas of high signal intensity according to age, and separate analyses were performed for girls and boys. Thirty-nine patients with a median follow-up of 7 years were analyzed. Focal areas of high signal intensity were found in 100% of patients, preferentially in the infratentorial white matter (35% cerebellum, 30% brain stem) and in the capsular lenticular region (22%). They measured 15mm in 95% of cases. The areas appeared from the age of 1 year; increased in number, size, and surface area to a peak at the age of 7; and then spontane

Deep Learning for Pediatric Posterior Fossa Tumor Detection and Classification: A Multi-Institutional Study

Editor’s Choice This study cohort comprised 617 children (median age, 92 months; 56% males) from 5 pediatric institutions with posterior fossa tumors: diffuse midline glioma of the pons, medulloblastoma, pilocytic astrocytoma, and ependymoma. There were 199 controls. Tumor histology served as ground truth except for diffuse midline glioma of the pons, which was primarily diagnosed by MR imaging. A modified ResNeXt-50-32x4d architecture served as the backbone for a multitask classifier model, using T2-weighted MRI as input to detect the presence of tumor and predict tumor class. Model tumor detection accuracy exceeded an AUC of 0.99 and was similar to that of 4 radiologists. Model tumor classification accuracy was 92% with an F1 score of 0.80. The model was most accurate at predicting diffuse midline glioma of the pons, followed by pilocytic astrocytoma and medulloblastoma. Ependymoma prediction was the least accurate. Abstract BACKGROUND AND PURPOSE CAMs depicting the areas o

MRI Findings of Immune Checkpoint Inhibitor–Induced Hypophysitis: Possible Association with Fibrosis

Fellows’ Journal Club This retrospective international multicenter study comprised 20 patients with melanoma who were being treated with immune checkpoint inhibitors and clinically diagnosed with immune checkpoint inhibitor–induced hypophysitis. Three radiologists evaluated the following MR imaging findings: enlargement of the pituitary gland and stalk; homogeneity of enhancement of the pituitary gland; presence/absence of a well-defined poorly enhanced area and, if present, its location, shape, and signal intensity in T2WI; and enhancement pattern in contrast-enhanced dynamic MR imaging. Enlargement of the pituitary gland and stalk was observed in 12 and 20 patients, respectively. Nineteen patients showed poorly enhanced lesions (geographic hypoenhancing lesions) in the anterior lobe, and 11 of these lesions showed hypointensity on T2WI. Thyrotropin deficiency and corticotropin deficiency were observed in 19/20 and 12/17 patients, respectively. The authors conclude that pituitary ge

Myelin and Axonal Damage in Normal-Appearing White Matter in Patients with Moyamoya Disease

Editor’s Choice Eighteen patients with Moyamoya disease (16–55 years of age) and 18 age- and sex-matched healthy controls were evaluated with myelin-sensitive MR imaging based on magnetization transfer saturation imaging and 2-shell diffusion MR imaging. The myelin volume fraction, which reflects the amount of myelin sheath; the g-ratio, which represents the ratio of the inner (axon) to the outer (axon plus myelin) diameter of the fiber; and the axon volume fraction, which reflects axonal components, were calculated and compared between the patients and controls. Compared with the healthy controls, the patients with Moyamoya disease showed a significant decrease in the myelin and axon volume fractions in many WM regions, while the increases in the g-ratio values were not statistically significant. Correlations with cognitive performance were most frequently observed with the axon volume fraction. The authors conclude that the relationship with cognitive performance might be stronger

Predictors of Favorable Outcome after Endovascular Thrombectomy in MRI: Selected Patients with Acute Basilar Artery Occlusion

Fellows’ Journal Club The authors analyzed consecutive MR imaging–selected patients with acute basilar artery occlusions endovascularly treated within the first 24 hours after symptom onset. Successful and complete reperfusion was defined as modified TICI scores 2b–3 and 3, respectively. Outcome at 90 days was analyzed. One hundred ten patients were included. In 10 patients, endovascular treatment was aborted for failed proximal/distal access. Overall, successful reperfusion was achieved in 81.8% of cases. At 90 days, favorable outcome was 31.8%, with a mortality rate of 40.9%; the prevalence of symptomatic intracranial hemorrhage within 24 hours was 2.7%. The median time from symptom onset to groin puncture was 410 minutes. In this series of MR imaging–selected patients with acute basilar artery occlusions, complete reperfusion was the strongest predictor of a good outcome. Lower pretreatment NIHSS, the presence of posterior communicating artery collateral flow, the absence of atria

Manganese-Enhanced MRI in Patients with Multiple Sclerosis

Editor’s Choice Mangafodipir is a manganese chelate that was clinically approved for MR imaging of liver lesions. The authors present a case series of 6 adults with multiple sclerosis who were scanned at baseline with gadolinium, then injected with mangafodipir, and followed at variable time points. Fourteen new lesions formed during or shortly before the study, of which 10 demonstrated manganese enhancement of varying intensity, timing, and spatial pattern. One gadolinium-enhancing extra-axial mass, presumably a meningioma, also demonstrated enhancement with manganese. Manganese enhancement was detected in lesions that formed in the days after mangafodipir injection, and this enhancement persisted for several weeks. They conclude that multiple sclerosis lesions were enhanced with a temporal and spatial profile distinct from that of gadolinium. Abstract BACKGROUND AND PURPOSE Mangafodipir enhancement of an active gadolinium-enhancing lesion (participant 1). At screening, this