Compressive symptoms in fusiform intracranial aneurysms: insights from vessel wall enhancement imaging

PURPOSE: Fusiform intracranial aneurysms (FIAs) may cause progressive symptoms due to mass effect on adjacent structures. We quantitatively assessed aneurysm wall enhancement (AWE) in FIAs and its association with compressive symptoms. METHODS: We retrospectively analyzed patients with unruptured FIAs who underwent 3T high-resolution MRI at three institutions in the USA and China. Symptomatic status was defined by clinical symptoms with imaging evidence of aneurysm-related mass effect, including cranial neuropathies, non-focal headache associated with aneurysm compression, or hydrocephalus. Three-dimensional AWE maps quantified signal intensity (SI) across the aneurysm wall (3D-AWE) and at focal compressive interfaces (focal AWE). 3D-AWE and focal AWE were compared between symptomatic and asymptomatic FIAs. Logistic regression identified factors associated with symptomatic presentation. RESULTS: Forty-eight patients were included (median age 58 years). Symptomatic FIAs (n=16, 33%) were larger than asymptomatic FIAs (16.3 mm vs 8.6 mm, P=0.001) and showed higher 3D-AWE (1.18 vs 0.82, P<0.001) and focal AWE (1.37 vs 0.92, P=0.009). Independent predictors included female sex (OR 4.58; P=0.027), size (OR 1.38; P=0.002), 3D-AWE (OR 8.17; P=0.002), and focal AWE (OR 24.8; P=0.011). Models incorporating size and AWE yielded AUCs of 0.88 for 3D-AWE and 0.91 for focal AWE. In a subgroup analysis restricted to FIAs ≥10 mm, symptomatic FIAs had greater 3D-AWE (1.22 vs 0.90, P=0.039) and focal AWE (1.25 vs 0.89, P=0.013) than asymptomatic FIAs. CONCLUSION: FIAs with compressive symptoms had increased 3D-AWE and focal AWE. These features have the potential to be used in the identification of aneurysms that may become symptomatic.