Objective: It remains unclear whether patients with unruptured intracranial aneurysms (UICAs) should be treated. Vessel wall enhancement (VWE) in vessel wall MRI is emerging as a useful biomarker of aneurysm instability. We sought to evaluate whether VWE correlates with clinical and radiological markers of aneurysm instability in patients with UICAs.
Methods: We conducted a retrospective analysis of a prospective cohort of patients with UICAs imaged with vessel wall MRI. Two blinded reviewers evaluated the presence of VWE. Univariate and multivariate logistic regression modelling was utilized to assess for association between VWE and (1) presence of cranial nerve palsy (CNP) and thunderclap headache on presentation, two well-established clinical markers of aneurysm instability; and (2) aneurysm size, a well-established radiological marker of aneurysm instability.
Results: 94 patients with UICAs were included in the analysis; of these, 34 (36%) had VWE, 60 (64%) did not, 10 (11%) had CNP, 14 (15%) presented with thunderclap headache, and 40 (43%) had aneurysms >7mm in size. Inter-rater reliability for VWE ascertainment was excellent (kappa 0.86, 95%CI 0.75-0.97). 9 out of 10 patients (90%) with CNP had VWE (association testing not possible due to sparse counts). In multivariable analysis, thunderclap headache (OR 8.55, 95%CI 1.89-45.64; p=0.007) and aneurysm size (1.26, 95%CI 1.10-1.50; p=0.003) were independently associated with VWE.
Conclusions: VWE independently associates with clinical and radiological markers of aneurysm instability. Prospective studies are needed to evaluate the clinical utility of this imaging biomarker.