Wall enhancement ratio and partial wall enhancement on MRI associated with the rupture of intracranial aneurysms.

OBJECTIVES: To evaluate the risk factors for rupture of intracranial aneurysms (IAs) using high resolution MRI (HRMRI).

METHODS: 91 consecutive patients with 106 IAs were reviewed from February 2016 to April 2017. Patients and IAs were divided into ruptured and unruptured groups. In addition to the clinical characteristics of the patients, the features of IAs (eg, shape) were evaluated by CT angiography, whereas wall thickness, enhanced patterns, and enhancement ratio (ER) were evaluated by MRI. Multiple logistic regression analysis was used to identify independent risk factors associated with the rupture of IAs. Receiver operating characteristic curve analysis was performed on the final model, and the optimal thresholds were obtained.

RESULTS: ER (OR 6.638) and partial wall enhancement (PWE) (OR 6.710) were not markers of aneurysms more prone to rupture, but simply were more commonly found in the ruptured aneurysm cohort. The threshold value for ER was 61.5%.

CONCLUSIONS: ER (≥61.5%) and IAs with PWE are better predictors of rupture. Increased attentions should be paid to these factors during assessment of IA rupture.