Study Shows Viability of Enhanced 3T MRI for Predicting Intracranial Aneurysm Instability

The use of aneurysm wall enhancement (AWE) with 3T MRI offers significant prognostic insight for patients with unruptured intracranial aneurysms (UIAs), according to new research. For the prospective study, recently published in JAMA Neurology, researchers reviewed enhanced 3T MRI AWE imaging at baseline as well as baseline and follow-up computed tomography angiography (CTA) images for 1,351 patients (median age of 56). There were 1,416 UIAs in the cohort with aneurysm instability according in 235 of the UIAs within a four-year period, according to the study. The study authors found that the four-year cumulative risk of aneurysm instability for UIAs with circumferential AWE was 36.8 percent in comparison to 17.2 percent for UIAs with focal AWE and 11.4 percent for UIAs with no AWE. For risk stratification, the researchers determined that circumferential AWE was associated with a 3.8-fold higher risk of intracranial aneurysm instability within four years. “Results of this cohort study show that UIAs with circumferential wall enhancement on MRI after administration of gadolinium were associated with an increased risk of aneurysm instability during a follow-up period of 4 years compared with those with focal or no wall enhancement. Circumferential AWE was an independent predictor of 4-year aneurysm instability,” wrote lead study author Qingyuan Liu, M.D., who is affiliated with the Department of Neurosurgery at the Beijing Tiantan Hospital and the China National Clinical Research Center for Neurological Diseases, and colleagues. Three Key Takeaways Circumferential AWE is a strong predictor of risk. Patients with circumferential aneurysm wall enhancement on 3T MRI had a 3.8-fold higher risk of aneurysm instability within four years. 2. AWE adds prognostic value beyond traditional scores. Unlike PHASES and ELAPSS, which focus mainly on aneurysm size, location, and clinical features, AWE provides direct insight into wall pathology (e.g., inflammation, atherosclerosis) and better stratifies risk. 3. Other key risk factors remain relevant. Irregular shape, circumferential AWE, and posterior circulation/Pcom location were independent predictors of higher instability risk, supporting their continued use in UIA assessment. Based on adjusted hazard ratios from the multivariable analysis of AWE with 3T MRI, the study authors found that other predictive factors for aneurysm instability included: • a 4.53-fold higher risk with irregular shape; • more than double the risk with a circumferential AWE pattern; and • a 70 percent higher risk with posterior circulation/posterior communication artery (Pcom) location. “(Aneurysm wall enhancement) could indicate the pathological features and fragility of aneurysm wall, including inflammation infiltration and atherosclerosis. The traditional scores, including PHASES and ELAPSS score, mainly pay attention to clinical features and aneurysm size and location, which lack assessment of pathological features and fragility of aneurysm wall. (Aneurysm wall enhancement) could provide additional information to clinicians to evaluate the risk of aneurysm instability,” added Liu and colleagues. (Editor’s note: For related content, see “Multicenter Study Assesses Intrasaccular Flow Disruption for Treating Sidewall Aneurysms,” “Improving Adherence to Best Practices for Incidental Abdominal Aortic Aneurysms on CT and MRI” and “Study: AI Model Significantly Enhances CTA Workflow Efficiency and Detection for Cerebral Aneurysm.”) In regard to study limitations, the authors conceded the potential of patient selection bias and acknowledged that the findings with the entirely Chinese patient cohort may have limited extrapolation to broader patient populations.