[Computed tomography in the diagnosis and surveillance of cerebrovascular accidents]

In cerebral hemorrhage, it provides an easy and early diagnosis, by demonstrating hyperdensity indicative of the presence of coagulated blood in the cerebral tissue. During the course of the illness, this hyperdensity progressively lessens, to disappear within a varying interval of time. The sequelae are seen as a cavity, the density of which is close to that of the CSF. In cerebral infarctions, the scan remains normal for the first few hours, and its only value at this stage is to eliminate cerebral hemorrhage before anticoagulants are prescribed. It is only after 24 to 48 hours that the fundamental sign is seen, that is hypodensity of the ischemic territory. This hypodensity may be accompanied by a mass effect and, above all, the uptake of contrast, which may be of great diagnostic importance, and the significance of which has been widely discussed. The course takes the form of the progressive development of the sequelary cystic appearance.