TOMOGRAPHIC STUDY IN MAN OF BLOOD AND OXYGEN-CONSUMPTION OF BRAIN BY CONTINUOUS INHALATION OF O-15 - PRELIMINARY FINDINGS IN CEREBRAL ISCHEMIC-ACCIDENTS

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  • 1 January 1978
    • journal article
    • research article
    • Vol. 134  (10) , 545-556
Abstract
Regional cerebral blood flow (rCBF) and regional O2 extraction fraction (rOEF) were studied in 13 patients hospitalized for ischemic strokes (11 middle cerebral artery territory infarcts, 1 capsular or pontine lacuna, 1 transient hemispheric attack) by continuous inhalation of 15O2 and C15O2 to equilibrium and detection of the .gamma. rays emitted in coincidence by a transverse axial tomograph for positron emitting agents. In the transient ischemic attack and in the lacuna, the rCBF and the rOEF images were normal, they were abnormal in all cases of middle cerebral artery territory infarcts. In recent infarcts, rOEF was decreased in the clinically suspected area, while the rCBF was either decreased, normal or increased. In infarcts older than 30 days, rCBF was decreased over the clinically suspected area while rOEF was in most cases normal or slightly decreased. These results and some practical and theoretical limitations of the method are discussed. The potential of the present technique is great, as it is possible to simultaneously visualize the blood flow and the O2 metabolism in small volume, deep areas of the brain. The parameters studied are being quantified and the theoretical model on which the method is based is being verified. Advantages of the method are its non-invasiveness, repeatability at regular intervals and used for measuring the immediate effects of a given therapeutic mode on the regional metabolism of brain.