Combined use of regional cerebral blood flow measurement and computerized tomography for the diagnosis of cerebral ischemia

Abstract

In previous reports (4,5,12–14) we have shown that the preoperative measurement of regional cerebral blood flow (rCBF) will considerably aid in establishing criteria for the selection of patients for extra- intracranial arterial bypass surgery. Using this technique, it is not only possible to determine directly and quantitatively the severity of brain ischemia but also to outline precisely the extent of the ischemic brain region, which will then allow us to direct the new collateral blood flow individually to that cortical area with actual hemodynamic compromise. It was also found from our material that the information obtained from rCBF studies is more reliable than that from cerebral angiography, which often fails to demonstrate any vascular abnormality, particularly in the situation of transient ischemic cerebral attacks (TIA). It must be emphasized, however, that the rCBF method can hardly be employed on a routine base in the preoperative evaluation of all potential candidates for bypass surgery. Mainly, it is a traumatic procedure because of the necessity of a carotid puncture. There are, in addition, various methodologic problems involved which are making the interpretation of results difficult at times.