PROBLEM TO BE SOLVED: To provide a nuclear medicine diagnostic device configured to simply calculate SUV with high accuracy.SOLUTION: A nuclear medicine diagnostic device includes: a nuclear medicine diagnostic device a medical image diagnostic device a volume calculation section, and an SUV calculation section. The nuclear medicine diagnostic device generates a nuclear medicine image of a subject injected with an FDG test drug having a radioisotope embedded therein. The medical image diagnostic device generates a morphology image of the subject. The volume calculation section calculates volume of the subject, on the basis of the morphology image. The SUV calculation section calculates SUV of the radioisotope, on the basis of the calculated volume.
