Magnetic Resonance Angiography Demonstrates Vascular Healing of Carotid and Vertebral Artery Dissections

Abstract

Background and Purpose Dissection of the carotid and vertebral arteries is most accurately diagnosed with conventional angiography. MR techniques are sensitive for detecting the abnormalities associated with dissection but may lack specificity. We hypothesized that MR may be useful for serial monitoring of dissection and may therefore guide therapy. Methods All patients with angiographically proven carotid and/or vertebral artery dissection from July 1994 to June 1996 were followed for a median duration of 10.5 months. Of these 29 patients (44 vessels), 18 were concurrently evaluated with MR, and a target group of 9 patients (17 vessels) was prospectively followed with MR at 3-month intervals. Results In the 18 patients with both imaging studies at baseline, angiography revealed 30 dissected vessels while MR detected 27 (90%). In the target group of 9 patients, initial MR identified 15 of the 17 dissections diagnosed with angiography. Serial MR revealed complete healing in 5 vessels, improvement in 6 vessels, no change in 4 vessels, and worsening in 2 vessels. The radiographic features most likely to resolve were stenosis and mural hematoma, while occlusion and luminal irregularity tended to persist. Late ischemic events occurred in 2 patients, both with persistent MR evidence of dissection, one while subtherapeutic on warfarin therapy and the other occurring 1 week after warfarin was discontinued. Conclusions MR is a reliable noninvasive method for following the vascular response to treatment and may guide the course of a clinical trial comparing medical therapies for carotid and vertebral artery dissection.