In vivo measurement of CBF using 17 O NMR signal of metabolically produced H 2 17 O as a perfusion tracer

The cerebral metabolic rate of oxygen of small animals can be reliably imaged using the in vivo 17 O magnetic resonance approach at high field. However, a separate measurement is required for imaging the cerebral blood flow in the same animal. In this study, we demonstrate that the 17 O NMR signal of metabolically produced H 2 17 O in the rat brain following an 17 O 2 inhalation can serve as a perfusion tracer and its decay rate can be used to determine the absolute values of cerebral blood flow across a wide range of animal conditions. This finding suggests that the in vivo 17 O magnetic resonance approach is capable of imaging both cerebral metabolic rate of oxygen and cerebral blood flow simultaneously and noninvasively; and it provides new utilities for studying the cerebral oxygen metabolism and perfusion commonly associated with brain function and diseases. Magn Reson Med 70:309–314, 2013. © 2012 Wiley Periodicals, Inc.