Correlation of angiography and MR imaging in cerebral vasculitis

Purpose: MR imaging and cerebral angiography were correlated in patients wi th primary angiitis of the central nervous system (PACNS) to assess the rel ative roles of these imaging modalities in the diagnosis. Material and Methods: In 9 patients, MR imaging and angiography were compar ed with regard to the relative involvement of each major vascular territory . Vascular territories assessed were the anterior, middle, and posterior ce rebral arteries, and the posterior fossa. Results: All patients had angiographic findings consistent with vasculitis in multiple vascular territories. MR findings ranged from normal to diffuse ly abnormal. One patient had a completely normal MR investigation. Of 50 te rritories affected by vasculitis on angiography, 17 (34%) were normal on MR . Conclusion: Relative to cerebral angiography, MR imaging is a poor indicato r of the presence or absence of PACNS. Angiography is indicated when clinic al suspicion of PACNS is strong, regardless of the findings on MR.