Fellows’ Journal Club

Acute Basilar Artery Occlusion: Differences in Characteristics and Outcomes after Endovascular Therapy between Patients with and without Underlying Severe Atherosclerotic Stenosis

Fellows’ Journal Club

Sixty-two patients with acute basilar artery occlusion underwent multimodal endovascular therapy with stent-retriever thrombectomy as a first-line endovascular therapy. Patients with underlying intracranial atherosclerotic stenosis underwent additional intracranial angioplasty and stent placement. Underlying intracranial atherosclerotic stenosis was identified at the occlusion site in 15 patients (24.1%). Occlusion in the proximal segment of the basilar artery was more common in patients with intracranial atherosclerotic stenosis (60% versus 6.4%), whereas occlusion in the distal segment was more common in those without it. Patients with and without underlying intracranial atherosclerotic stenosis who underwent endovascular therapy had similar outcomes.

Volumetric Analysis from a Harmonized Multisite Brain MRI Study of a Single Subject with Multiple Sclerosis

Fellows’ Journal Club

The North American Imaging in Multiple Sclerosis Cooperative steering committee developed a uniform high-resolution 3T MR imaging protocol relevant to the quantification of cerebral lesions and atrophy and implemented it at 7 sites across the United States. They assessed intersite variability in scan data, by imaging a volunteer with relapsing-remitting MS with a scan-rescan at each site. In multicenter studies with consistent scanner field strength and manufacturer after protocol harmonization, systematic differences can lead to severe biases in volumetric analyses.

TIPIC Syndrome: Beyond the Myth of Carotidynia, a New Distinct Unclassified Entity

Fellows’ Journal Club

This study included 47 patients from 10 centers presenting between January 2009 through April 2016with acute neck pain or tenderness and at least 1 cervical image showing unclassified carotid abnormalities. The authors conducted a systematic, retrospective study of their medical charts and diagnostic and follow-up imaging. All patients presented with acute neck pain, and 8 presented with transient neurologic symptoms. Imaging showed an eccentric pericarotidian infiltration in all patients. An intimal soft plaque was noted in 16 patients, and a mild luminal narrowing was noted in 16 patients. The authors conclude that this study improves the description of an unclassified, clinico-radiologic entity, which could be described by the proposed acronym: Transient Perivascular Inflammation of the Carotid artery (TIPIC) syndrome.

Prevalence of Traumatic Findings on Routine MRI in a Large Cohort of Professional Fighters

Fellows’ Journal Club

Conventional 3T MR imaging was used to assess 499 fighters (boxers, mixed martial artists, and martial artists) and 62 controls for nonspecific WM changes, cerebral microhemorrhage, cavum septum pellucidum, and cavum vergae. Fighters had an increased prevalence of cerebral microhemorrhage (4.2% versus 0% for controls), cavum septum pellucidum (53.1% versus 17.7% for controls), and cavum vergae (14.4% versus 0% for controls). This study assessed MR imaging findings in a large cohort demonstrating a significantly increased prevalence of cavum septum pellucidum among fighters. Although cerebral microhemorrhages were higher in fighters than in controls, this finding was not statistically significant.

Baseline Survey of the Neuroradiology Work Environment in the United States with Reported Trends in Clinical Work, Nonclinical Work, Perceptions of Trainees, and Burnout Metrics

Fellows’ Journal Club

A voluntary survey was sent to practicing and out-of-training members of the ASNR. Four hundred thirty-two respondents across a broad range of experience reported: 93% with workdays extending at least 1 hour past expected; 71.9% reading more cases per hour compared with previous years; 79.5% sometimes-to-always interpreting cases faster than comfortable for optimal interpretation; and 67.8% sometimes or more often with inadequate time to discuss abnormal results. Burnout symptoms ranged between 49% and 75%. The trends and the correlations should be concerning to the leaders of radiology and warrant further monitoring.

Clinically Feasible Microstructural MRI to Quantify Cervical Spinal Cord Tissue Injury Using DTI, MT, and T2*-Weighted Imaging: Assessment of Normative Data and Reliability

Fellows’ Journal Club

Forty healthy subjects underwent T2WI, DTI, magnetization transfer, and T2*WI at 3T in <35 minutes using standard hardware and pulse sequences. Cross-sectional area, fractional anisotropy, magnetization transfer ratio, and T2*WI WM/GM signal intensity ratio were calculated. Reliable multiparametric assessment of spinal cord microstructure is possible by using clinically suitable methods. These results establish normalization procedures and pave the way for clinical studies.

Large Basilar Apex Aneurysms Treated with Flow-Diverter Stents

Fellows’ Journal Club

The authors report their experience treating basilar apex aneurysms with flow-diverter stents and evaluate their efficacy and safety profile in this specific condition. Of the 175 aneurysms treated with flow-diverter stents at their institution, 5 patients received flow-diverter stents for basilar apex aneurysms. The mean follow-up after stent deployment was 21 months. They conclude that flow diversion is a feasible technique with an efficacy demonstrated at a midterm follow-up, especially in the case of basilar apex aneurysm recurrences after previous endovascular treatments.

Differentiation of Enhancing Glioma and Primary Central Nervous System Lymphoma by Texture-Based Machine Learning

Fellows’ Journal Club

The authors evaluated the diagnostic performance of a machine-learning algorithm by using texture analysis of contrast-enhanced T1-weighted images for differentiation of primary central nervous system lymphoma (n=35) and enhancing glioma (n=71). The mean areas under the receiver operating characteristic curve were 0.877 for the support vector machine classifier; 0.878 for reader 1; 0.899 for reader 2; and 0.845 for reader 3. They conclude that support vector machine classification based on textural features of contrast-enhanced T1WI is noninferior to expert human evaluation in the differentiation of primary central nervous system lymphoma and enhancing glioma.

Intraforaminal Location of Thoracolumbar Radicular Arteries Providing an Anterior Radiculomedullary Artery Using Flat Panel Catheter Angiotomography

Fellows’ Journal Club

Ninety-four flat panel catheter angiotomography acquisitions obtained during the selective injection of intersegmental arteries providing an anterior radiculomedullary artery were reviewed. The location of radicular arteries could be ascertained in 78/94 flat panel catheter angiotomography acquisitions. Fifty-three acquisitions (67.9%) were on the left side, and 25 (32.1%), on the right, between T2 and L3. The arteries were found in the anterosuperior quadrant in 75 cases (96.2%), in the posterosuperior quadrant in 2 (2.6%), and in the anteroinferior quadrant in 1(1.3%). Needle placement in the anterosuperior quadrant (subpedicular approach) should be avoided during transforaminal epidural steroid injection. The authors advocate the posterolateral approach that allows placing the needle tip away from the documented position of ARMA contributors within the neural foramen, reducing the risk of intra-arterial injection or injury to the spinal vascularization.

Clinical and Imaging Characteristics of Diffuse Intracranial Dolichoectasia

Fellows’ Journal Club

The authors retrospectively reviewed a consecutive series of patients with diffuse intracranial dolichoectasia and compared demographics, vascular risk factors, additional aneurysm prevalence, and clinical outcomes with a group of patients with vertebrobasilar dolichoectasia. Twenty-five patients had diffuse intracranial dolichoectasia, and 139 had vertebrobasilar dolichoectasia. Patients with diffuse intracranial dolichoectasia were older than those with vertebrobasilar dolichoectasia and had a higher prevalence of abdominal aortic aneurysms, other visceral aneurysms, and smoking history. Patients with diffuse intracranial dolichoectasia were more likely to have aneurysm growth. They conclude that the natural history of patients with diffuse intracranial dolichoectasia is significantly worse than that in those with isolated vertebrobasilar dolichoectasia.