In the 1940s, Seymour S. Kety and Carl F. Schmidt measured cerebral blood flow in awake humans by means of subanesthetic doses of inhaled nitrous oxide. The inhalation route obviated the need for an arterial injection of the indicator, and nitrous oxide had virtues of metabolic inertness, rapid diffusion through the blood-brain barrier, comparable blood and brain solubility, and ease of analytical detection. The technique was also applied to the heart. Follow-up work by Kety contributed to the development of brain scanning methods.
Keywords: Edmond I. Eger II; Ephedrine; Functional Magnetic Resonance Imaging; James E. Eckenhoff; John W. Severinghaus; Minimum Alveolar Concentration; Paul C. Zamecnik; Positron Emission Tomography; Robert D. Dripps.
Copyright © 2020. Published by Elsevier Inc.