1029. Aneurysm wall enhancement in black blood MRI correlates with aneurysm size. A study on 71 Patients with 90 Aneurysms.

Authors: Athanasios Petridis, MD, IFAANS; Chasoglou Elias; Igor Fischer; Hans Jakob Steiger; Rebecca May (Duesseldorf, Germany)

Introduction: Finding of incidental intracranial aneurysms leads to the dilemma to treat or to observe. Even though clinical scoring systems consider risk factors for aneurysm rupture, objective parameters for assessment of aneurysms stability are needed. Methods: Retrospective analysis on patients seen in our institution from January 1st 2017 until July 30th 2017. The correlation of contrast enhancing aneurysm wall (AWCE) behaviour of un-ruptured aneurysms in the black blood MRI in N=71 patients with 90 aneurysms with aneurysm anatomy and clinical scoring systems is evaluated. Results: AWCE is associated with aneurysm height and height to width ratio in ICA aneurysms. AWCE correlates to larger aneurysms. The mean size of the contrast enhancing aneurysms is significantly different between anatomical localizations indicating separate analyses for every artery. A subgroup analysis of AWCE, height and specific localization of aneurysms was performed and revealed that the mean height of aneurysms with AWCE was 13.6 mm for ICA aneurysms; 7.6 mm for AcomA aneurysms and 6.6 mm for MCA aneurysms. The ICA aneurysms with contrast enhancement were significantly greater in size than AcomA and MCA aneurysms (p<0.01). Clinical scoring systems like PHASES and UIATS correlate positively with AWCE in black blood MRI. Conclusion: MRI aneurysm wall contrast enhancement is a positive predictor for aneurysm instability. Aneurysms smaller than 7 mm with AWCE should be followed closely with focus on growth, as they may be prone to growth and rupture.