Rai, Pranjal

BACKGROUND: Cerebral hemodynamic impairment in patients with asymptomatic high-grade (>70%) internal carotid artery (ICA) stenosis is associated with risk of stroke and cognitive decline, but correlations between the degree of stenosis and hemodynamic impairment are derived from small case series. Using baseline data from 242 participants in the CREST-H study (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis–Hemodynamics), we hypothesized that the degree of stenosis in the ICA would correlate with time-to-peak (TTP) delay in ipsilateral cerebral blood flow using MR/CT perfusion scans, adjusting for demographic and cardiovascular risk variables. METHODS: From all participants, ICAs were insonated using a 7 to 10 MHz probe for peak systolic velocity (PSV) and end diastolic velocity. Dynamic contrast perfusion imaging was standardized across 61 CREST-H sites, using standard sequential T2*-weighted perfusion imaging. CT perfusion used standard clinical protocols. TTP delay was calculated in the ipsilateral versus contralateral hemispheres. In cross-sectional analysis, linear regression was used to model TTP delay as the outcome variable and PSV, end diastolic velocity, and PSV ICA/common carotid artery ratio on the index and nonindex side as primary predictor variables in 6 separate models, adjusting for covariates, followed by automated backward elimination model reduction. RESULTS: Among 392 CREST-H participants, the 242 with complete data for all variables were included in the regression analysis (age, 70±7.6; 62% M). End diastolic velocity on the index side correlated with TTP delay (β=0.003, P =0.005). PSV had a similar correlation but did not reach significance (β=0.001, P =0.099), nor did ICA/common carotid artery ratio (β=0.003, P =0.126). Nonindex side PSV, end diastolic velocity, and ICA/common carotid artery ratio showed no correlation with TTP delay ( P =0.268, P =0.495, P =0.380, respectively). Circle of Willis completeness did not correlate with TTP. CONCLUSIONS: In this large cohort of patients with high-grade asymptomatic carotid stenosis, higher end-diastolic flow velocities correlated with greater TTP delays, supporting a definition of hemodynamically significant stenosis. Our findings have implications for the management of asymptomatic carotid stenosis, which will be tested in the CREST-H study. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03121209.

Background Dual antiplatelet therapy (DAPT) is recommended around carotid artery stenting (CAS) to reduce periprocedural stroke risk. Clopidogrel is widely used, but response variability related to pharmacokinetics and CYP2C19 polymorphisms may limit its effectiveness. Ticagrelor is a more potent, direct acting P2Y12 inhibitor, but its comparative effectiveness in CAS remains uncertain. Methods We conducted a retrospective cohort study in the TriNetX database, identifying adults with carotid artery stenosis who underwent CAS between January 2016 and August 2025 and received either ticagrelor or clopidogrel. Primary outcomes at 180 days included ischemic stroke, major hemorrhage, intracranial hemorrhage, and all cause mortality. Secondary outcomes included inpatient readmission and emergency department (ED) visits. Propensity score matching (1:1), Kaplan–Meier survival, and Cox proportional hazards analysis were used. Results Among 6996 patients, 378 received ticagrelor and 6618 received clopidogrel; aspirin co-use was similar (89.7% vs 91.7%). After matching, 377 patients remained in each cohort. Ischemic stroke (2.7% vs 4.2%; HR 0.56, 95% CI 0.25 to 1.27; P=0.159) and major hemorrhage (2.9% vs 4.8%; HR 0.61, 95% CI 0.29 to 1.30; P=0.197) were numerically lower with ticagrelor. Rates of intracranial hemorrhage were similar (2.7% vs 2.7%; HR 0.61, 95% CI 0.14 to 2.53; P=0.488). Mortality was numerically higher with ticagrelor (3.4% vs 2.7%; HR 1.64, 95% CI 0.68 to 3.97; P=0.263). ED visits were similar (14.3% vs 14.6%; HR 0.97, 95% CI 0.67 to 1.42; P=0.895). Inpatient readmission was numerically lower with ticagrelor (15.9% vs 19.1%; HR 0.81, 95% CI 0.57 to 1.14; P=0.223). Conclusion Ticagrelor and clopidogrel showed comparable safety and effectiveness following CAS. Future prospective genotype informed trials are warranted to confirm these findings.

FRACTURE MRI demonstrated strong agreement with conventional radiography and CT in evaluating key bone tumor characteristics, including lesion type, location, and matrix content.

Metastatic meningioma exhibits diverse dissemination patterns across organ systems (lungs, bone, liver, soft tissue, etc), with molecular imaging—particularly gallium 68 DOTA Tyr3-octreotide PET/CT—playing a pivotal role in detection, characterization, and guiding management.

A 3-month-old infant presented with a painless, gradually enlarging swelling in their right orbital and temporal region. What is your diagnosis?

Despite their similar nomenclature, Neurofibromatosis type 1 (NF1) and “Neurofibromatosis type 2” are discrete and clinically distinguishable entities. The name of “neurofibromatosis type 2” has been changed to NF2-related schwannomatosis, to reflect the fact that neurofibromas do not occur in this syndrome and therefore the name “Neurofibromatosis” is factually incorrect. Furthermore, multiple schwannomas, a hallmark feature of NF2, can also occur in patients with mutations in genes including SMARCB1 and LZTR1, all exhibiting overlapping clinical features. Current understanding suggests that schwannomatosis (SWN) encompasses a range of clinical presentations consisting of clearly defined, separate subtypes which share a common phenotype of schwannomas. Recognizing these newly emerging subtypes, the International Consensus Group on Neurofibromatosis Diagnostic Criteria (I-NF-DC) proposed a revised nomenclature for NF2 and related disorders in 2022. This review article focuses on this critical update in diagnostic terminology, highlighting the key gene-related SWN subtypes relevant to neuroradiologists. By emphasizing molecular testing alongside clinical features, the revised system facilitates a more precise diagnosis, potentially paving the way for personalized treatment strategies. Additionally, the flexible structure accommodates future discoveries of genes associated with SWN.