[Evaluation of regional brain circulation by dynamic computer tomography]

Regional brain circulation was evaluated by dynamic computed tomography with iodine enhancement. The CT number (Hounsfield unit)-time curve provided us three parameters, namely, peak value, rapid washout ratio and filling time. It was indicated that these three parameters were related to different components. Peak value was related to blood volume, rapid washout ratio to transit time and filling time to filling velocity and/or distance from the point of injection to the site of measurement. In 10 patients with brain edema, both peak value and rapid washout ratio were decreased, comparing to these of 5 normal subjects. In 24 patients with cerebral infarction, decreased peak value was a main finding. In 3 patients with occlusion of internal carotid artery, delayed filling time was demonstrated in every patient. Clinical application of dynamic computed tomography was discussed.