PET, CT, and MR imaging in cerebrovascular disease.

Forty-five patients with cerebrovascular disease (single and multiple infarcts, intracerebral hemorrhages) were examined with X-ray CT, magnetic resonance (MR) imaging, and positron emission tomography (PET). In six patients with acute infarcts repeat measurements with all techniques were performed after 2 weeks. Magnetic resonance and PET were more sensitive in the detection of ischemic lesions than X-ray CT. With PET, functional disturbances could be demonstrated even in two cases where CT and MR were normal, while the latter techniques were superior in exactly localizing a lesion. Changes in lesion appearance with time were observed with all techniques, and the pathophysiologically important phenomena of hyperperfusion or hypermetabolism were documented in four infarcts with PET.