Wall Enhancement in Evolving Cerebral Aneurysms on Magnetic Resonance Vessel Wall Imaging

Abstract

Abstract INTRODUCTION Recent magnetic resonance (MR) vessel wall imaging studies have indicated cerebral aneurysms in the active state could show wall enhancement along the aneurysm wall (CEAW). While ruptured aneurysms frequently show CEAW, CEAW in the unruptured aneurysms at evolving state, ie growing or symptomatic, has not been studied in detail. We assessed the degree of CEAW in evolving unruptured aneurysms by comparing separately with each of those in stable unruptured aneurysms and ruptured aneurysms. METHODS We performed quantitative analyses of CEAW in consecutive 26 evolving aneurysms using MR vessel wall imaging. Three-dimensional T1-weighted fast spin-echo sequence was obtained before and after contrast media injection, and the contrast ratio of aneurysm wall against the pituitary stalk (CRstalk) was calculated as the indicator of CEAW. We compared aneurysm characteristics of evolving aneurysms with those of 69 stable unruptured and 67 ruptured aneurysms. RESULTS The CRstalk in evolving aneurysms was significantly higher than those in stable aneurysms (0.54 vs 0.34; P < .0001), and lower than those in ruptured aneurysms (0.54 vs 0.83; P < .0002). In multivariable analysis, CRstalk remained significant in comparing evolving with stable aneurysms (odds ratio, 12.23; 95% confidence interval, 3.53-42.41), and with ruptured aneurysms (odds ratio, 0.083; 95% confidence interval, 0.022-0.310). CONCLUSION The CEAW in evolving aneurysms was higher than those in stable aneurysms, and lower than those in ruptured aneurysms.