High-resolution MR vessel wall imaging in determining the stroke aetiology and risk stratification in isolated middle cerebral artery disease

Abstract

High-resolution MR vessel wall imaging (HRVWI) can characterise vessel wall pathology affecting intracranial circulation and helps in differentiating intracranial vasculopathies. The aim was to differentiate intracranial pathologies involving middle cerebral artery (MCA) in patients with ischemic stroke and characterise the high-risk plaques in intracranial atherosclerotic disease (ICAD) using HRVWI. Patients with ischemic stroke with isolated MCA disease with ≥ 50% luminal narrowing by vascular imaging were enrolled within 2weeks of onset and underwent high-resolution (3T) intracranial vessel wall imaging (VWI). The pattern of vessel wall thickening, high signal on T1-weighted images, juxtaluminal hyperintensity, pattern and grade of enhancement were studied. The TOAST classification before and after HRVWI and the correlation of the recurrence of ischemic events at 3months with imaging characteristics were analysed. Of the 36 patients, the mean age was 49.53 ± 15.61years. After luminal imaging, by TOAST classification, 12 of 36 patients had stroke of undetermined aetiology. After vessel wall imaging, lesions in MCA were analysed. Of them, 23 patients had ICAD, 8 had vasculitis, and 2 had partially occlusive thrombus in MCA. The ability of HRVWI to bring a change in diagnosis was significant (p = 0.031). Of the 23 patients with ICAD, 12 patients had recurrent strokes within 3months. The presence of grade 2 contrast enhancement (p = 0.02) and type 2 wall thickening (p = 0.03) showed a statistically significant association with recurrent ischemic events. High-resolution MRVWI can help in identifying the aetiology of stroke. The HRVWI characteristics in ICAD can help in risk stratification.