Vessel wall image as a marker of cerebral aneurysm instability.

[BACKGROUND] Intracranial aneurysms affect 3% of the population, with advancements in radiology enabling more diagnoses of unruptured aneurysms. The black blood magnetic resonance imaging (bbMRI) is a valuable noninvasive method to study of the inflammatory process in the wall of intracranial arteries. This study aimed to correlate wall enhancement of aneurysms through bbMRI with known risk factors.

[METHODS] A retrospective analysis was conducted on patients who had microsurgery for ruptured and unruptured intracranial aneurysms from June 2020 to March 2023. Patient demographics and radiological findings were reviewed with qualitative variables analyzed using Fisher's exact test and quantitative variables using the Mann‒ Whitney.

[RESULTS] We analyzed 120 patients and 139 aneurysms. All patients underwent microsurgery for clipping at least one aneurysm. Female was more prone to exhibit ruptured aneurysms than males (28% vs. 8%, + 0.03, odds ratio [OR] = 0.2, 95% confidence interval [CI] 95% = 0.04-0.9). Ruptured aneurysms were more likely to have a diameter ≥7 mm (50% ruptured vc. 23.8% unruptured, = 0.05, OR = 0.3, 95% CI = 0.1-0.6). bbMRI was positive in 76.5% of ruptured aneurysms and 23.5% were negative ( < 0.0001). In the unruptured aneurysm group, the larger the aneurysm was, the greater the chance of positive bbMRI (OR = 0.1, 95% CI = 0.05-0.3). In this subgroup, either size or positive bbMRI was associated with rupture.

[CONCLUSION] Our analysis demonstrated that ruptured aneurysms are more prone to be positive on bbMRI, that is, aneurysm wall enhancement after the administration of contrast. This reinforces the association between positive bbMRI and aneurysm instability.