Imaging findings in primary central nervous system vasculitis

Primary central nervous system vasculitis (PCNSV) is a rare primary vasculitis limited to the brain and spinal cord. It can affect any age group, but has a predilection for subjects aged 40 to 60 years without clear gender predominance. Clinical manifestations are non-specific, including headache, non-focal neurological features and, less frequently, focal neurological signs. Brain biopsy is the diagnostic gold standard, but may be falsely negative when unaffected tissue is sampled. In addition, brain biopsy carries a small but significant risk of serious complications. Imaging procedures are a key part of the workup of PCNSV patients. They can be used to document the extent and type of lesions, to gauge response to treatment, and sometimes as surrogates for brain biopsy. Magnetic resonance is extremely sensitive but non-specific. The most common findings are multiple bilateral ischaemic lesions often involving white and grey matter. Conventional or magnetic resonance angiography (MRA) typically shows segmental narrowing and dilation in multiple cerebral arteries. However, atypical findings have also been described both with magnetic resonance and angiography. This review discusses the state-of-the-art of current imaging techniques in the workup of PCNSV patients and highlights future prospects.