Improved method for noninvasive measurement of regional cerebral blood flow by 133Xenon inhalation. Part II: measurements in health and disease.

Abstract

The current state of noninvasive measurement of regional cerebral blood flow (rCBF) by inhalation of 133Xe gas is briefly reviewed. Apparatus is now available commercially so that printouts of rCBF values for gray and white matter flow of both cerebral hemispheres, and probably the brain stem and cerebellum, are available within 30 min after 1 min inhalation of 5-6 mCi of the gas mixed in air. The printout is in the form of a brain map which shows normal values. Normal values reported in volunteers are discussed and modifications of rCBF caused by normal physiological function such as sleep, attention, activation, speech, hearing, performance of tasks and the normal aging process are reviewed. Noninvasive rCBF measurements have some practical clinical and investigative applications in the evaluation of pathological states such as cerebrovascular disease, the dementias, migraine, epilepsy, narcolepsy and head injuries. Despite certain technical limitations of the 133Xe inhalation method, which are described, rCBF measurements show promise for future screening of populations at risk from cerebrovascular disease, early identification of stroke-prone individuals, evaluation of methods of prevention, and measurement of the effects of medical and surgical treatment.