Arterial wall enhancement overlying carotid plaque on CT angiography correlates with symptoms in patients with high grade stenosis

Background and Purpose-: The degree of internal carotid artery (ICA) stenosis is an established primary risk factor for embolic stroke. Recent publications suggest that inflammatory features may also play an important role. Our purpose was to correlate acute neurological symptoms with either carotid artery wall enhancement or plaque calcification, on axial CT angiographic source images (CTA-SI) of patients with severe (70%) ICA stenosis. Methods-: 75 consecutive patients with 70% ICA stenosis on CTA-SI were identified. Each case was classified as symptomatic (n=37) or asymptomatic (n=38), and as having either calcified or noncalcified plaque. The latter group was stratified into those with versus without arterial wall enhancement, measured in absolute and relative Hounsfield Units (HU). Results-: Calcified plaque was present in 39% (15/38) of the symptomatic patients and in 62% (23/37) of the asymptomatic patients (P=0.065). Of the 37 patients without calcified plaque, carotid wall enhancement was observed in 83% (19/23) of the symptomatic, but only in 57% (8/14) of the asymptomatic patients (P=0.041). When the "calcified plaque" and "no carotid wall enhancement" groups were pooled, versus the "carotid wall enhancement" group, enhancement was more likely in symptomatic patients (OR 3.625, CI 95% 1.3229 to 9.93, P=0.01 Fisher Exact test). Conclusions-: In patients with severe ICA stenosis, additional stratification of stroke risk may be possible based on the presence of carotid wall enhancement on CTA-SI. Patients with carotid wall enhancement are more likely to be symptomatic, compared to those with either calcified plaque or no enhancement.