Cerebral amyloid angiopathy: CT and MR imaging findings.

Cerebral amyloid angiopathy (CAA) is an important but underrecognized cause of cerebrovascular disorders that predominantly affect elderly patients. CAA results from deposition of beta-amyloid protein in cortical, subcortical, and leptomeningeal vessels. This deposition is responsible for the wide spectrum of clinical symptoms and neuroimaging findings. Many cases of CAA are asymptomatic. However, when cases are symptomatic, patients can present with transient neurologic events, progressive cognitive decline, or potentially devastating intracranial hemorrhage. Computed tomography is the imaging study of choice for evaluation of suspected acute cortical hemorrhage, which may be accompanied by subarachnoid, subdural, or intraventricular hemorrhage. Magnetic resonance imaging is best suited for identification of small or chronic cortical hemorrhages and ischemic sequelae of this disease, exclusion of other causes of acute cortical-subcortical hemorrhage, and assessment of disease progression. Accurate recognition of imaging findings is important in guiding clinical decision making in patients with CAA.