Natural History of Asymptomatic Unruptured Cerebral Aneurysms Evaluated at CT Angiography: Growth and Rupture Incidence and Correlation with Epidemiologic Risk Factors

CT angiographic examination showed growth in nearly 18% of intracranial aneurysms of all sizes, which is associated with a 12-fold higher risk of rupture (P < .002), supporting follow-up of all aneurysms, including those smaller than the current 7-mm treatment threshold.