How can you differentiate vessel wall enhancement related to CNS vasculitis versus atherosclerotic changes on MRA brain vessel wall imaging?

On MRA brain vessel wall imaging (vWI), central nervous system (CNS) vasculitis typically presents with concentric, uniform vessel wall enhancement and thickening, reflecting a diffuse inflammatory process involving the entire circumference of the vessel wall. In contrast, atherosclerotic changes more commonly exhibit eccentric wall enhancement and thickening, often with additional features such as calcification or irregular luminal narrowing. The concentric enhancement pattern of vasculitis helps differentiate it from the asymmetric, focal involvement characteristic of atherosclerosis. Also, vasculitis may affect smaller, distal vessels and can appear multifocal, whereas atherosclerosis usually involves larger, proximal vessels and occurs ...