THE MEASUREMENT OF CEREBRAL BLOOD FLOW BY EXTERNAL ISOTOPE COUNTING*

The measurement of cerebral blood flow by external isotope counting.

The Kety-Schmidt nitrous oxide method (2) is presently the only well-accepted technique for the quantitative estimation of human cerebral perfusion. In spite of theoretical objections (3) and practical limitations it has provided a wealth of otherwise unobtainable information. The procedure is tedious, however, and has remained predominantly a laboratory research tool. Efforts have continued to...

Serial measurement of cerebral blood flow using external counting of microspheres.

Described is a modified method of measuring organ blood flow which combines the serial injection of a standard dose of microspheres and the external counting of their gamma activity when they are distributed to the tissues. The method produces similar results to measurements of grey matter blood flow by the clearance of 133xenon.

Measurement of total cerebral blood flow in the monkey by external monitoring of cesium-131.

Measurement of coronary blood flow by external counting with radioactive rubidium. Critical appraisal and validation of the method.

T HE MYOCARDIAL clearance of potassium (MCK) can be measured by means of precordial counting after single intravenous injection of 42KC1 or 86RbCl.1 It may be considered to measure coronary blood flow per unit mass of myocardium under the assumption that the average extraction of the indicator by the myocardium during the first minutes after injection does not differ significantly from the aver...

Newer techniques of cerebral blood flow measurement.

• A variety of methods for measuring cerebral blood flow have been developed in the past 25 years since Kety and Schmidt developed their method based on the Fick principle. None of the currently used methods approaches the clinical ideal, since none of the techniques are accurate, reproducible and noninvasive. Most accurate techniques involve catheterization of internal carotid artery and/or ju...