Cross-validation of Input Functions Obtained by H2 15O PET Imaging of Rat Heart and a Blood Flow-through Detector

Purpose Positron emission tomography (PET) with 15O-labeled water (H215O) facilitates the visualization and quantification of blood flow in clinical investigations and also in small animals. The quantification of blood flow requires an input function, which is generally obtained by measuring radioactivity in arterial blood withdrawn during PET scanning. However, this approach is not always feasible, because abundant blood sampling may affect the physiological process being measured. The purpose of the present study was to develop and cross-validate two methods, namely, a blood- and an image-based method for obtaining the input function for blood flow studies from rat H215O PET.