Brain oxygen utilization measured with oxygen-15 radiotracers and positron emission tomography: generation of metabolic images.

We recently described a PET method for the measurement of local brain tissue oxygen extraction (E) and the local cerebral metabolic rate for oxygen (CMRO2) using 15O-labeled radiotracers. The equation for the calculation of E from measured PET data is mathematically complex and its direct application in the generation of PET images of either E or the CMRO2 on a pixel-by-pixel basis is computationally burdensome. We describe a simplification of this equation which permits the efficient generation of quantitative images.