Validation of Wall Enhancement as a New Imaging Biomarker of Unruptured Cerebral Aneurysm

Background and Purpose— High-resolution vessel wall magnetic resonance imaging is a promising technique for assessing wall structures of unruptured intracranial aneurysms (UIAs). However, the relationship between aneurysmal high-resolution vessel wall magnetic resonance imaging features and their histopathologic mechanism remains poorly understood. Methods— From February 2016 to February 2018, a total of 19 men and 28 women with 54 UIAs treated surgically were prospectively enrolled. The intraoperative observed gross pathology of the aneurysmal wall was compared with the enhancement features on high-resolution vessel wall magnetic resonance imaging. Specimens of the UIAs were harvested for histopathologic and immunohistochemistry analysis. Results— An irregular shape and large size was significantly related to UIA wall enhancement. Both uniform and focal wall enhancement may demonstrate the inflammation processes of UIA walls, although the latter may indicate more atherosclerotic plaque formation. Conclusions— Different high-resolution vessel wall magnetic resonance imaging enhancement features may represent variable inflammation status of a UIA wall, which may provide new insights into assessing the UIA wall structure and optimizing treatment.