# Temporal changes in symptomatic intracranial arterial disease: a longitudinal high-resolution vessel wall imaging study

## TL;DR

This study tracks how narrowing of brain arteries changes over time in stroke patients, finding that different causes of artery narrowing have distinct patterns of change.

## Contribution

The study reveals distinct temporal patterns of intracranial arterial narrowing based on stroke etiology using serial high-resolution vessel wall imaging.

## Key findings

- Intracranial dissection shows faster reduction in stenosis and enhancing proportion compared to atherosclerosis.
- Enhancement ratio decreases over time in atherosclerosis but remains stable in dissection.
- Temporal changes in vessel wall imaging parameters differ significantly by stroke etiology.

## Abstract

The temporal dynamics of the vessel wall in intracranial arterial disease (ICAD) may differ depending on the etiology. We investigated temporal changes in narrowed intracranial arteries after ischemic stroke using serial high-resolution vessel wall imaging (HR-VWI).

We retrospectively recruited patients with ICAD-related ischemic stroke who underwent two or more HR-VWI scans. The lumen area (LA), total vessel area (TVA), and enhancing area (EA) of the narrowest part of the culprit lesion were manually segmented. Degree of stenosis was estimated as [1-LA/TVA] × 100(%), the enhancing proportion as EA/TVA × 100(%), and enhancement ratio as (T1GDlesion/T1GDref)/(T1lesion/T1ref). Linear mixed models were used to investigate temporal changes in these parameters and whether such changes differed by etiologies.

Of a total of 208 patients, ICAD-related stroke was caused by atherosclerosis (69%), arterial dissection (24%), vasculitis (3%), moyamoya disease (1%), and other (2%). The median follow-up was 319 [IQR, 125–409] days. HR-VWI imaging parameters, namely, degree of stenosis, enhancing proportion, and enhancement ratio showed a trend to decrease over time. Patients with intracranial dissection as a cause of intracranial narrowing showed a faster reduction in degree of stenosis and enhancing proportion vs. when such narrowing was identified as due to atherosclerosis (β [95% CI], −0.59%[−0.80% ~ −0.38%] and −0.81%[−1.23% ~ −0.39%], respectively, both p < 0.01). The enhancement ratio did not change over time in dissection, while it decreased in atherosclerosis (−0.01 [−0.02 ~ 0], p = 0.04).

Intracranial vessel narrowing in patients with ischemic stroke changes over time with different stroke etiologies having their own unique temporal patterns.