The useful of dynamic CT scan on the actue stage of ischemic cerbrovascukar disease

CT scan offers only pictorial information, but dynamic CT scan, which consists of intrabenous bolus injection of the contrast medium and high speed sequence scanning, offers information on the careful circulation. We performed dynamic CT scan on the actue stage of 40 cases of ischemic cerebrovascular disease and it was very useful in the evaluation of the cerebral circulation and in establishing a therapeutic plan. The time-density curve of dynamic CT scan was divided into three types by peak (P) value of the curve. In type A cases, the difference between the curves of the affected side and the non-affected side was not recognized, and the prognosis of these cases was verygood even by conservative therapy. In type B cases, the peak value of the affected side was in the range of 30 to 70% of the non-affected side, and a decreasein cerebral blood flow was suggesuted. In these cases, no low density srea appeared in plain CT scan and the neurological signs improved when the cerebral blood flow recovered, whereas a low density area appeared when the carebral blood flow did not recover. In type C cases, the curve of the affected side was nearly flat and a marked decrease in the cerebral blood flow was suggested. In these cases a low density area on plain CT scan appeared immediately and the prognosis was very poor. The ecaluation of the time-density curve of dynamic CT scan indicated actue cerebral revascularization in the cases where Type B curves were shown.