Island Sign on Computed Tomography Is Associated With Cerebral Amyloid Angiopathy in Patients With Intracerebral Hemorrhage

Background Irregular hematoma border is a prominent yet understudied imaging feature of cerebral amyloid angiopathy (CAA)‐related intracerebral hemorrhage (ICH). We investigated whether island sign and irregular shape could be an additional imaging marker of CAA‐related ICH. Methods This cross‐sectional analysis included a prospective cohort of consecutive patients with supratentorial ICH with both computed tomography and magnetic resonance imaging. Presence of island sign and irregular shape on computed tomography was assessed blinded to clinical and magnetic resonance imaging data. The primary outcome was probable CAA by Boston criteria v2.0. Multivariable logistic regression analysis was conducted to evaluate associations of island sign or irregular shape with probable CAA. Diagnostic accuracy of the simplified Edinburgh criteria before and after incorporating island sign or irregular shape was compared using area under the receiver operating characteristics curve and DeLong test. Results Among 488 patients, 51 (10.5%) patients had CAA‐ICH. Island sign (39.2% versus 4.1%, P