CT-detected hemorrhagic infarction; relation with the size of the infarct, and the presence of midline shift.

The incidence of mass effect indicated by midline shift, and the incidence of hemorrhagic infarction were studied in 952 consecutive CT scans with supratentorial infarcts. Hemorrhagic infarction was found in 5.1% indicating that the incidence of hemorrhagic infarction during life is far less than was suggested from pathological studies. Midline shift was found in 3.6% and, accordingly, the chance of finding a hemorrhagic infarct with mass effect indicated by a shift of the midline would be 0.2% if these 2 phenomena were not related. However, this incidence appeared to be 12 times higher, indicating they are closely related. In addition, the incidence of hemorrhagic infarcts and midline shift were both related to large infarcts with bad outcome. Cardiac emboli were not more prevalent in patients with hemorrhagic infarcts than in a control series, indicating that cardiac emboli do not produce hemorrhagic infarction more often than other causes of cerebral infarction, and that cardiac embolic cause cannot be inferred from hemorrhagic infarction on CT. This probably also applies to carotid emboli. When anticoagulation is considered in patients with cerebral infarction, CT-confirmed hemorrhagic infarction and shift of midline structures as well as decreased consciousness are contraindications to such treatment. In their absence, and in the absence of general contraindications, anticoagulant treatment can safely be started.