It is possible to reduce the time required for checking the in vivo behavior of oxygen molecules by using 0-15 marked oxygen in PET imaging. For this, marked oxygen and marked water or marked carbon dioxide are continuously applied to an examinee with a time difference, during which an activity concentration of an organ of the examinee is obtained by one PET imaging. Simultaneously with this, an activity concentration of the blood of the examinee is obtained. The measurement data is used in an expression including the behavior of oxygen molecules of the organ, the behavior of water molecules generated by metabolism in vivo, and an activity concentration in the blood vessel. A superposition integration part is calculated for a plurality of discrete values of blood stream within a certain range. The aforementioned expression of the activity concentration is obtained by the method of least squares. The local brain bloodstream, the brain oxygen update ratio or the brain oxygen metabolic amount is calculated and a quantized image is obtained.
DEVICE AND METHOD FOR QUANTIZING IMAGE BY PET IMAGING