Contrast enhancement was studied with computed tomography in 18 patients with brain infarction. Four patients were examined on > 1 occasion. A mode of contrast medium administration was used that results in constant blood I concentration during the investigation. The enhancement pattern was analyzed using a compartment model. A fast and a slow component of contrast enhancement was quantified for different parts of the infarct. Correlation with the age of the infarct confirms earlier studies, indicating a maximum enhancement at 2-4 wk after the incidence of the infarct.