CNS vasculitis in autoimmune disease: MR imaging findings and correlation with angiography

BACKGROUND AND PURPOSE: MR findings in CNS vasculitis and their correlation with angiography have not been clearly defined. We therefore explored three hypotheses regarding CNS vasculitis associated with autoimmune disease: 1) MR imaging is highly sensitive; 2) a typical MR appearance exists; and, 3) MR and angiographic findings correlate well. METHODS: We studied 18 patients with CNS vasculitis associated with autoimmune disease, characterized the MR lesions by type, size, number, and location, and correlated the MR findings with those of angiography. RESULTS: All patients with CNS vasculitis had abnormalities on MR studies. On average, four ± two lesions per patient were detected on MR images. The lesions were located in the subcortical white matter (n = 20), cortical gray matter (n = 16), deep gray matter (n = 16), deep white matter (n = 9), and cerebellum (n = 9). Only 65% of MR lesions were evident on angiograms; 44% of the lesions revealed on angiograms were detected by MR. CONCLUSION: MR imaging is sensitive for CNS vasculitis. Lesions attributable to CNS vasculitis in autoimmune disease are distributed nearly equally among cortical, subcortical, and deep gray matter structures. The modest correlation between MR imaging and angiography suggests that the two techniques provide different information about CNS vasculitis and that both types of studies are needed for the complete assessment of damage caused by vascular abnormalities.