DETECTABILITY OF ACUTE SUPRATENTORIAL BRA IN INFARCTIONS BY COMPUTED-TOMOGRAPHY

In this study the detectability of supratentorial brain infarctions by CT with regard to the time interval after symptom onset and to the in farction type and size was evaluated. 206 patients with supratentorial brain infarctions of whom a CT scan was performed within 24 hours aft er symptom onset were selected for this study. Signs of early ischaemi a, infarction type and size were determined by two examiners, the diag nosis was confirmed by follow-up CT's. Eighty-seven percent of the ter ritorial infarctions were recognised, the rate of defection did not in crease after the first hour. The hyperdense middle cerebral artery sig n (HMCAS) was found in 40% of all MCA infarctions. It was however pres ent in 83% within the first 90 minutes and in only 18% from hour 12 to 24. All lentiform nucleus-MCA infarcts and 95% of the larger MCA infa rcts but only 77 (i.e. 68%) of the infarctions covering less than 33% of the MCA territory, were detected. Among the haemodynamic infarction s all watershed infarctions, but only 30 (i.e. 53%) of the terminal su pply area infarctions were recognised. The detectability of supratento rial brain infarctions therefore mainly depends on infarction type and size. The detection rate of territorial infarctions after the first h our corresponds with the infarction size, but not with the time interv al. The HMCAS is the earliest sign of ischaemia; however, it is suffic iently sensitive only within the first 90 minutes.