Brief Inhalation Method To Measure Cerebral Oxygen Extraction Fraction with PET: Accuracy Determination Under Pathologic Conditions

• Published in: The Journal of nuclear medicine (1978) Vol. 32; no. 9; p. 1738
• Main Authors: Altman, Denis I, Lich, Lennis L, Powers, William J
• Format: Journal Article
• Language: English
• Published: United States Soc Nuclear Med 01.09.1991
• Subjects: ACCURACY; ANIMALS; BLOOD FLOW; BODY; BRAIN; Brain - diagnostic imaging; Brain - physiology; Brain - physiopathology; CENTRAL NERVOUS SYSTEM; CEREBRAL CORTEX; Cerebrovascular Circulation - physiology; CEREBRUM; COMPUTERIZED SIMULATION; COMPUTERIZED TOMOGRAPHY; DIAGNOSIS; DIAGNOSTIC TECHNIQUES; DISEASES; ELEMENTS; EMISSION COMPUTED TOMOGRAPHY; INHALATION; INTAKE; Macaca nemestrina; MACACUS; MAMMALS; MATHEMATICS; METABOLISM; MONKEYS; NERVOUS SYSTEM; NONMETALS; ORGANS; OXYGEN; Oxygen Consumption - physiology; Oxygen Radioisotopes; Papio; POSITRON COMPUTED TOMOGRAPHY; PRIMATES; RADIOLOGY AND NUCLEAR MEDICINE; REGRESSION ANALYSIS; SENSITIVITY ANALYSIS; SIMULATION; STATISTICS; Time Factors; TOMOGRAPHY; Tomography, Emission-Computed; VASCULAR DISEASES; VERTEBRATES 550601 > Medicine > Unsealed Radionuclides in Diagnostics
• ISSN: 0161-5505; 1535-5667

The initial validation of the brief inhalation method to measure cerebral oxygen extraction fraction (OEF) with positron emission tomography (PET) was performed in non-human primates with predominantly normal cerebral oxygen metabolism (CMRO2). Sensitivity analysis by computer simulation, however, indicated that this method may be subject to increasing error as CMRO2 decreases. Accuracy of the method under pathologic conditions of reduced CMRO2 has not been determined. Since reduced CMRO2 values are observed frequently in newborn infants and in regions of ischemia and infarction in adults, we determined the accuracy of the brief inhalation method in non-human primates by comparing OEF measured with PET to OEF measured by arteriovenous oxygen difference (A-VO2) under pathologic conditions of reduced CMRO2 (0.27-2.68 ml 100g-1 min-1). A regression equation of OEF (PET) = 1.07 x OEF (A-VO2) + 0.017 (r = 0.99, n = 12) was obtained. The absolute error in oxygen extraction measured with PET was small (mean 0.03 +/- 0.04, range -0.03 to 0.12) and was independent of cerebral blood flow, cerebral blood volume, CMRO2, or OEF. The percent error was higher (19 +/- 37), particularly when OEF is below 0.15. These data indicate that the brief inhalation method can be used for measurement of cerebral oxygen extraction and cerebral oxygen metabolism under pathologic conditions of reduced cerebral oxygen metabolism, with these limitations borne in mind.