Abstract 38: Temporal Changes in Intracranial Arterial Diseases: A Longitudinal High-Resolution Vessel Wall Imaging Analysis

Abstract

Introduction: Temporal changes of intracranial arterial disease (ICAD) in patients with ischemic stroke in high-resolution vessel wall imaging (HR-VWI) have not been elucidated. Methods: We recruited consecutive ICAD-related ischemic stroke patients admitted between June 2016 and June 2019 and had subsequent HR-VWI follow-ups. On HR-VWI, we manually segmented the lumen area (LA), total vessel area (TVA), and enhancing area (EA) of the culprit lesion's most stenotic part in the perpendicular section on T1-weighted, proton density, and post-contrast T1-weighted sequences. We defined the area stenosis as [1-LA/TVA]х100 (%) and the enhancing proportion as EA/TVAх100 (%). Enhancement ratio of the enhancing lesion was also quantified. Three raters independently quantified the imaging using ITK-SNAP with acceptable inter-rater reliability. Results: A total of 208 patients (age 57±14, male 58%) with 469 HR-VWIs (2-6 scans per patient) were included. The causes of ICAD were atherosclerosis (69%), dissection (24%), vasculitis (3%), moyamoya disease (1%), and other causes (2%). The median follow-up duration was 9.0 months (interquartile range: 3.9-13.2 months), and the maximum follow-up duration was 41.3 months. Among patients with atherosclerosis, area stenosis aggravated, stable, and improved in 7%, 77%, and 16%, respectively, with an overall rate of 0.23 ± 0.07% improvement per month. Among patients with dissection, area stenosis aggravated, stable, and improved in 2%, 49%, and 49%, respectively, with an overall rate of 2.11 ± 0.26% improvement per month (Figure, P -for-difference < 0.01). The temporal changes of the enhancing proportion and enhancement ratio were different between atherosclerosis and dissection (Figure, P < 0.01). Conclusions: ICAD lesions had dynamic changes over time; the temporal changes of atherosclerosis and dissection are distinct. Serial HR-VWI can offer insights for a more accurate diagnosis of the underlying pathologies of ICADs.