Hyperintense Carotid Plaque on T1-Weighted Turbo-Field Echo MRI in Symptomatic Patients with Low-Grade Carotid Stenosis and Carotid Occlusion

Abstract

Background: In addition to stenosis grading, magnetic resonance imaging (MRI) may provide valuable information about plaque ‘status’, e.g. hyperintense vulnerable carotid plaque, associated with higher morbidity and mortality. In the present study, we investigated the prevalence, clinical and radiological correlates of hyperintense carotid plaques on T₁-weighted turbo-field echo (T₁w-TFE) MRI in patients with ischemic symptoms. Methods: A total of 153 patients presenting with transient ischemic attack or ischemic infarct, studied with contrast-enhanced magnetic resonance angiography (CEMRA), were retrospectively examined. Stenosis grade was obtained from CEMRA images, presence or absence of hyperintense carotid plaque from T₁w-TFE MRI. Stenosis grade and baseline characteristics were compared between patients with and without a hyperintense plaque. Results: Twenty-eight patients (18%) showed one or more hyperintense internal carotid (ICA) plaques. Hyperintense plaques were found in patients with <50% stenosis (6 of 158 ICAs), 50–70% stenosis (4 of 11), >70% stenosis (14 of 74) and carotid occlusion (4 of 28). Presence of hyperintense plaque was associated with older age (70 vs. 62 years; p < 0.05), higher prevalence of cardiac disease (61 vs. 28%; p < 0.01), ischemic infarct as presenting symptom (37 vs. 14%; p < 0.01), ischemic cerebral lesions on MRI (63 vs. 32%; p < 0.01), and the ICA on the patients’ symptomatic side (70 vs. 42%; p < 0.01). Conclusions: More than one third of patients with 50–70% stenosis present with a hyperintense plaque. This subgroup of patients could in the future possibly benefit from more aggressive medicinal therapy or revascularization.