Simultaneous Measurement of Cerebral Oxygen Consumption and Blood Flow Using 17O and 19F Magnetic Resonance Imaging

17 O and 19 F magnetic resonance (MR) imaging were used to determine simultaneously the concentrations of H 2 17 O and CHF 3 in 0.8-cc voxels in the cat brain during inhalation of a gas mixture containing both 17 O 2 and CHF 3 . The arterial time course of CHF 3 was determined by “on-line” mass spectrometer detection of expired CHF 3 , and the arterial time course of H 2 17 O was determined by 17 O MR analysis of arterial samples withdrawn during the inhalation period. The brain data and the arterial data for the two tracers were combined to calculate the cerebral oxygen consumption (CMRO 2 ) and the CBF. The protocol was repeated on seven cats, using pentobarbital anesthesia. The average values of CMRO 2 and CBF for a 0.8-cc voxel in the parietal cortex were 1.5 ± 0.5 mmol kg −1 min −1 and 38 ± 15 ml 100 g −1 min −1 , respectively. In individual animals the average uncertainty in CMRO 2 and CBF, calculated from Monte Carlo approaches, was ±9%.