Cerebral convexity subarachnoid hemorrhage: various causes and role of diagnostic imaging.

Computed tomography (CT) and magnetic resonance imaging (MRI) have made it relatively easy to diagnose cortical convexity subarachnoid hemorrhages (cSAH); however, the evaluation of these hemorrhages should not be limited to size and location. It is imperative that possible underlying etiologies be identified so that clinicians may properly treat and prevent this potentially catastrophic event. The goal of this article is to review etiologies of cortical convexity subarachnoid hemorrhages, from common causes such as cerebral amyloid angiopathy to less common causes such as reversible cerebral vasoconstriction syndrome and moyamoya. The specific imaging findings of each etiology that may be responsible for these hemorrhages are described in this article so that the radiologist may properly aid in the diagnosis of the underlying cause.