Cerebral blood flow measurement with oxygen-15 water positron emission tomography

Abstract

The human brain receives approximately 15% of the cardiac output and therefore is the most demanding organ in respect to blood flow supply. This fact emphasizes the importance of perfusion as a key factor in a variety of cerebrovascular and other diseases including stroke, migraine, and brain tumors. Today, numerous imaging techniques are able to visualize brain perfusion, but only few of them provide quantitative information. In the field of modern in vivo imaging techniques, positron emission tomography (PET) is considered to be the gold standard to give reliable results about major aspects of cerebral physiology. [15O]H2O allows for quantitative cerebral blood flow (CBF) measurement within a few minutes, and subsequent 15O[O2] imaging can provide precise information on oxygen metabolism like cerebral oxygen metabolism and oxygen extraction fraction. As a result, PET has become an extremely useful research tool for defining cerebral blood flow and physiology. However, complex methodological logistics and a limited availability of the imaging system hamper the widespread use of CBF PET in clinical routine. The chapter aims at summarizing the radiosynthesis, data acquisition, and analysis, as well as major preclinical and clinical applications of [15O]H2O PET.