Benson, John

Background Little is known about the impact that cardiovascular (CV) risk factors have on the formation of various carotid atherosclerotic plaque features. This study set out to assess the association between CV risk factors and plaque characteristics on computed tomography (CT) angiography (CTA). Materials and methods A retrospective review was completed of consecutive patients that underwent a carotid endarterectomy and had CTA imaging of the head and neck vasculature. Atherosclerotic plaques of both carotid arteries were evaluated for calcification(s), low-density plaque (LDP) components, ulceration(s), and degree of stenosis. Various clinical CV risk factors were assessed using medical records. Last recorded laboratory levels were dichotomized into categories: total cholesterol <200 or ≥200 mg/dL, low-density lipoprotein (LDL) <130 or ≥130 mg/dL, high-density lipoprotein <35 or ≥35 mg/dL, and triglyceride <200 or ≥200 mg/dL. Results Of 97 included patients, 62 were male (63.9%); the average age was 72.7 (standard deviation = 9.5). Calcifications were in 95/97 (97.9%) of patients (one or both carotid plaques); LDP components were in 73/97 (75.3%), and ulcerations were in 21/97 (21.6%). Elevated total cholesterol and elevated LDL levels were both associated with a higher likelihood of LDP components ( p = 0.004 and p = 0.02, respectively). There were no other statistically significant associations between individual plaque features or severity of arterial stenosis and CV risk factors. Conclusion In carotid atherosclerotic plaques, LDP components are more frequently present in one or both carotid arteries in patients with elevated total cholesterol and/or LDL levels. Such findings raise the possibility that cholesterol levels may be directly related to the formation of specific high-risk plaque features.

Background Using computed tomography angiography to differentiate between components of carotid atherosclerotic lesions remains largely elusive. This study sought to validate a semi-automated software for computed tomography angiography plaque analysis using histologic comparisons. Materials and Methods A retrospective review was performed of consecutive patients that underwent a carotid endarterectomy, with pre-procedural computed tomography angiography imaging of the cervical arterial vasculature available for review. Images were evaluated using a commercially-available software package, which produced segmented analyses of intraplaque components (e.g. intraplaque hemorrhage, lipid-rich necrotic core, and calcifications). On imaging, each component was assessed in terms of its (1) presence or absence, and (2) both volume and proportion of the total plaque volume (if present). On histological evaluation of carotid endarterectomy specimens, each component was evaluated as an estimated proportion of total plaque volume. Results Of 80 included patients, 30 (37.5%) were female. The average age was 69.7 years (SD = 9.1). Based on imaging, intraplaque hemorrhage was the smallest contributor to plaque composition (1.2% of volumes on average). Statistically significant linear associations were noted between the proportion of intraplaque hemorrhage, lipid-rich necrotic core, and calcifications on histology and the volume of each component on imaging ( p values ranged from 0.0008 to 0.01). Area under curve were poor for intraplaque hemorrhage and lipid-rich necrotic core (0.59 and 0.61, respectively) and acceptable for calcifications (0.73). Conclusion Semi-automated analyses of computed tomography angiography have limited diagnostic accuracy in the detection of intraplaque hemorrhage and lipid-rich necrotic core in carotid artery plaques. However, volumetric imaging measurements of different components corresponded with histologic analysis.

Introduction There is increased interest in the use of artificial intelligence-based (AI) software packages in the evaluation of neuroimaging studies for acute ischemic stroke. We studied whether, compared to standard image interpretation without AI, Brainomix e-ASPECTS software improved interobserver agreement and accuracy in detecting ASPECTS regions affected in anterior circulation LVO. Methods We included 60 consecutive patients with anterior circulation LVO who had TICI 3 revascularization within 60 minutes of their baseline CT. A total of 16 readers, including senior neuroradiologists, junior neuroradiologists and vascular neurologists participated. Readers interpreted CT scans on independent workstations and assessed final ASPECTS and evaluated whether each individual ASPECTS region was affected. Two months later, readers again evaluated the CT scans, but with assistance of e-ASPECTS software. We assessed interclass correlation coefficient for total ASPECTS and interobserver agreement with Fleiss’ Kappa for each ASPECTS region with and without assistance of the e-ASPECTS. We also assessed accuracy for the readers with and without e-ASPECTS assistance. In our assessment of accuracy, ground truth was the 24 hour CT in this cohort of patients who had prompt and complete revascularization. Results Interclass correlation coefficient for total ASPECTS without e-ASPECTS assistance was 0.395, indicating fair agreement compared, to 0.574 with e-ASPECTS assistance, indicating good agreement (P < 0.01). There was significant improvement in inter-rater agreement with e-ASPECTS assistance for each individual region with the exception of M6 and caudate. The e-ASPECTS software had higher accuracy than the overall cohort of readers (with and without e-ASPECTS assistance) for every region except the caudate. Conclusions Use of Brainomix e-ASPECTS software resulted in significant improvements in inter-rater agreement and accuracy of ASPECTS score evaluation in a large group of neuroradiologists and neurologists. e-ASPECTS software was more predictive of final infarct/ASPECTS than the overall group interpreting the CT scans with and without e-ASPECTS assistance.

Background Diffuse intracranial susceptibility abnormalities have recently been described among patients with coronavirus disease 2019 (COVID-19), although prior studies have consisted of case reports and/or series. This brief literature review seeks to compile and catalogue the available data to elucidate characteristic features of such findings. Materials and methods Scientific articles and studies on intracranial microhemorrhages in the setting of COVID-19 were searched on PubMed, Google Scholar, and the Cochrane Library. Included studies described intracranial microbleed(s) on magnetic resonance imaging in patients with COVID-19. If multiple patients were described, only patients with intracranial microhemorrhage on magnetic resonance imaging were included for analysis. Patient demographics, severity of illness (e.g. intensive care unit admission and/or intubation), time from diagnosis of COVID-19 to magnetic resonance imaging, and location(s) of any observed microhemorrhages were noted. Results A total of 39 patients with suspected intracranial microhemorrhages have been described in prior studies. The average age of patients was 64.7 years; 21.9% were women. The average time between COVID-19 diagnosis and magnetic resonance imaging was 31.7 days. All patients in the cohort were admitted to critical care and were either intubated or treated with extracorporeal membrane oxygenation during their clinical course. Microhemorrhages were most commonly located in the subcortical/juxtacortical white matter and corpus callosum. Conclusions Intracranial microbleeds are a well-documented finding in patients with severe COVID-19, and are most commonly callosal and subcortical/juxtacortical in location.

BackgroundFusion of diffusion‐weighted imaging (DWI) to computed tomography (CT) has been touted as a possible technique to improve cholesteatomas localization. This study set out to assess the ability of DWI images fused with thin‐slice heavily T2‐weighted images to similarly localize surgically‐confirmed cholesteatomas.Materials and MethodsA retrospective review was completed of consecutive patients that underwent MR temporal bone imaging (9/2011–3/2020) with both DWI and thin‐slice T2‐weighted imaging. Included patients underwent surgical resection of primary or recidivistic cholesteatoma after preoperative MR imaging. A neuroradiologist, who was blinded to operative and clinical notes, localized each lesion on both DWI and fused DWI‐T2 images in 11 anatomic subdivisions of the temporal bone. Surgical confirmation of cholesteatoma location was used as the gold standard for comparison.ResultsOf 24 included examinations, the average age at time of MR was 48.2 ± 24.7 years; 12/24 (50.0%) were female. Five of 24 had primary cholesteatoma, while the remainder had recidivistic disease. Sensitivity, specificity, and accuracy of unfused DWI images were 52.1%, 88.9%, and 75.8%, respectively. Sensitivity, specificity, and accuracy of fused DWI‐T2 images were 57.1%, 94.8%, and 81.8%, respectively.ConclusionFused DWI‐T2 images outperformed unfused DWI images in the anatomic localization of temporal bone cholesteatomas. This method represents a potential alternative to MR‐CT fusion for pre‐operative cholesteatoma evaluation, and warrants future investigations. Opposed to MR‐CT fusion, this method only necessitates MR sequences and removes the need for additional CT acquisition.Level of Evidence3 Laryngoscope, 131:E1662–E1667, 2021

Background To assess if leukoaraiosis severity is associated with outcome in patients with acute ischemic stroke (AIS) following endovascular thrombectomy, and to propose a leukoaraiosis-related modification to the ASPECTS score. Methods A retrospective review was completed of AIS patients that underwent mechanical thrombectomy for anterior circulation large vessel occlusion. The primary outcome measure was 90-day mRS. A proposed Leukoaraiosis-ASPECTS (“L-ASPECTS”) was calculated by subtracting from the traditional ASPECT based on leukoaraiosis severity (1 point subtracted if mild, 2 if moderate, 3 if severe). L-ASEPCTS score performance was validated using a consecutive cohort of 75 AIS LVO patients. Results 174 patients were included in this retrospective analysis: average age: 68.0±9.1. 28 (16.1%) had no leukoaraiosis, 66 (37.9%) had mild, 62 (35.6%) had moderate, and 18 (10.3%) had severe. Leukoaraiosis severity was associated with worse 90-day mRS among all patients (P=0.0005). Both L-ASPECTS and ASPECTS were associated with poor outcomes, but the area under the curve (AUC) was higher with L-ASPECTS (P<0.0001 and AUC=0.7 for L-ASPECTS; P=0.04 and AUC=0.59 for ASPECTS). In the validation cohort, the AUC for L-ASPECTS was 0.79 while the AUC for ASPECTS was 0.70. Of patients that had successful reperfusion (mTICI 2b/3), the AUC for traditional ASPECTS in predicting good functional outcome was 0.80: AUC for L-ASPECTS was 0.89. Conclusions Leukoaraiosis severity on pre-mechanical thrombectomy NCCT is associated with worse 90-day outcome in patients with AIS following endovascular recanalization, and is an independent risk factor for worse outcomes. A proposed L-ASPECTS score had stronger association with outcome than the traditional ASPECTS score.

Background and purpose Cervical internal carotid artery (ICA) tortuosity is thought to impede distal catheterization during attempted mechanical thrombectomy in patients with acute ischemic stroke. This study sought to assess the morphologic characteristics of ICAs and the effects of tortuosity on thrombectomy attempts. Methods A retrospective review was completed of neck CTAs of patients with acute ischemic stroke due to a large vessel occlusion that underwent attempted endovascular recanalization. Significant tortuosity of ICAs was defined as the presence of kink(s) (acute (<90°) angulation), loop(s) (C- or S-shaped curvature with 2+ areas of acute (<90°) angulation), or coil(s) (full 360° turn arterial bend). Findings were statistically compared to procedure time, successful recanalization rate, patient demographics, and co-morbidities. Results Of 120 included patients, 47 (39.2%) had some form of tortuosity of one or both ICAs. Twenty-eight patients (23.3%) had a kink of one or both ICAs; this was followed in frequency by loops (n = 20; 16.7%) and coils (n = 8; 6.7%). Kinks were associated with lower rates of successful recanalization (p = 0.02). The presence of any tortuosity (kinks, loops, or coils) was not associated with number of passes during thrombectomy (p = 0.88), successful recanalization (p = 0.11), or total procedure time (p = 0.22). No association was noted between the presence of tortuosity and age (p = 0.96) or prior or current tobacco use (p = 0.75 and p = 0.69, respectively). Conclusion Among patients referred for urgent revascularization for large vessel occlusion, approximately 40% exhibit some tortuosity. Kinks may portend lower likelihood of recanalization success, although tortuosity as a whole seems to have little effect on endovascular thrombectomy.

Background Carotid-cavernous fistulas (CCFs) are commonly misdiagnosed on computed tomography angiography (CTA). Purpose This study sought to identify the most sensitive and specific imaging features of CCFs on CTA. Material and Methods A retrospective review identified 18 consecutive patients suspected of having a CCF on CTA and subsequently underwent digital subtraction angiography (DSA). Two blinded reviewers assessed multiple findings on CTA: cavernous sinus asymmetry/enlargement; arterial-phase contrast in the cavernous sinus; proptosis; pre- or post-septal orbital edema; and dilated regional vasculature. Each was graded as positive, possible, and negative; “possible” was counted as positive. A third blinded reviewer served as a tiebreaker. Results Of 18 patients, nine were true-positive and nine were false-positive. Superior ophthalmic vein early enhancement and dilatation had 100.0% sensitivity (95% confidence interval [CI] 40.0–100.0) and 77.8% specificity (95% CI 44.4–100.0); arterial-phase contrast in the cavernous sinus had 88.9% sensitivity (95% CI 44.4–100.0) and 66.7% specificity (95% CI 18.5–90.1); peri-orbital edema had 88.9% sensitivity (95% CI 35.5–100.0) and 77.8% specificity (95% CI 22.2–100.0). The most specific markers of CCF were superior petrosal sinus and inferior ophthalmic vein dilatation/enhancement (100.0%, 95% CI 88.8–100.0 and 88.9%, 95% CI 44.4–100.0, respectively); the specificity of asymmetric cavernous enlargement was 44.4% (95% CI 11.1–77.7). Conclusions Among patients in whom a CCF is suspected on CTA, superior ophthalmic vein dilatation/enhancement and arterial-phase contrast within the cavernous sinus are the most sensitive findings. Asymmetric cavernous sinus enlargement has poor specificity and may result in false-positive diagnoses of CCFs. False positive cases were less likely to have an optimally timed contrast bolus.

Purpose Radiology descriptions of intracranial metastases following radiotherapy are often imprecise. This study sought to improve such reports by creating and disseminating a structured template that encourages discrete categorization of intracranial lesions. Methods Following initiation of the structured template, a retrospective review assessed patients with intracranial metastases that underwent radiotherapy, comparing ‘pre-template’ with ‘post-template’ reports. A total of 139 patients were included; 94 patients (67.6%) were imaged pre-template, 45 (32.4%) post-template. Reports were assessed for discrete versus non-specific descriptions of lesions: ‘(presumed) new metastases’, ‘treated metastases’, and ‘indeterminate lesions’. Non-specific language was subdivided based on the type of lesion(s) described: e.g. ‘stable enhancing foci’ was deemed a non-specific description of ‘treated metastases’. Results Non-specific descriptions of lesions were used in 25/94 reports (26.6%) pre-template, and eight reports (17.8%) post-template. No significant difference was found in the frequency of inappropriate/ambiguous descriptions of intracranial lesions following template initiation ( P = 0.52). However, only 27/45 (60.0%) of the reports in the post-template time period used the structured report; the other reports were written as free prose. Of the reports that did use the structured template, the authors used significantly less ambiguous language structured template ( P = 0.02). Conclusion When utilized, a structured report template resulted in decreased non-specific descriptions and improved discrete characterization of intracranial metastases in patients treated with radiation. However, the frequency of non-specific language usage before and after template initiation was unchanged, probably due to poor compliance with template utilization.