Relationship Between Aneurysm Wall Enhancement in Vessel Wall Magnetic Resonance Imaging and Rupture Risk of Unruptured Intracranial Aneurysms.

Abstract

The rupture risk assessment of unruptured intracranial aneurysms (IAs) is still challenging. Aneurysm wall enhancement (AWE) on vessel wall magnetic resonance imaging (VW-MRI) is suggested as a potential marker for wall inflammation, but its relationship with rupture risk of unruptured IAs has not been well described. To investigate the correlation between AWE and conventional rupture risk factor of unruptured IAs. Clinical data and VW-MRI images were retrospectively reviewed in patients with unruptured IAs from January 2015 to December 2016 in our center. One hundred ten patients harboring 140 unruptured IAs were included. The presence of AWE was determined by comparing the postcontrast VW-MRI images with the precontrast ones. The rupture risk based on the PHASES score was calculated for each case. Univariate and multivariate analysis were performed to investigate the association of AWE with rupture risk and other conventional risk factors. AWE was present in 82 (58.6%) lesions. Unruptured IAs with AWE had significantly larger size (P<.001), more irregular shape (P=.003), and different distribution of locations (P=.023) comparing with aneurysms without AWE. The rupture risk score of AWE group was significantly higher than non-AWE group (P<.001). Aneurysm size (odds ratio=1.536; 95% confidential interval 1.312-1.798; P<.001) and location (odds ratio=1.592; 95% confidential interval 1.237-2.049; P<.001) were independently related with AWE in multivariate analysis. The presence of AWE on VW-MRI was highly associated with conventional rupture-related characteristics, including aneurysmal size and location, and was detected more frequently in unruptured IAs with high rupture risk based on the PHASES score.