Follow-up CT of hemorrhagic cerebral infarction

The computed tomography (CT) findings in cases of hemorrhagic cerebral infarction were divided into the following two different patterns: (1) The precontrast scan showed small high-density spots, mainly at the cortico-subcortical junctions. These appeared to represent a small amount of hemorrhage. The contrast enhancements were remarkable around these high-density areas as observed by the plain CT. (2) The precontrast scan showed only low-density areas, but the contrast scan showed an enhancement at the border zone of the gray and white junction, similar to those observed in Type 1 CT. Three (20%) of the 15 patients presented Type 1, and 12 patients (80%), Type 2. In the cases of Type 1, a positive CE was seen within a few days after the insult. This CE demonstrated the disturbance of the blood-brain barrier (B B B) during the stage of vasogenic edema. In the cases of Type 2, the positive CE was further divided into two subtypes: the early stage (2 to 3 weeks) and the late stage (4 weeks) after the stroke. The positive CE at the early stage, might be explainable to a significant extent by an extravasation of the contrast medium resulting from permeability changes in the vessels located in the boundary zones of the gray and white matter. On the contrary, the CE enhancement observed in the late stage might result chiefly from newly formed vessels with a defective BBB in and around the infarcted area. (author)