According to one embodiment, a nuclear medicine imaging apparatus includes a detector, a calibrator, and an image reconstruction unit. The detector includes a plurality of detector modules, each counting light originating from a gamma ray. The calibrator unit calibrates time information of all of the plurality of detector modules by calibrating time information for determining each detection time of a pair of detector modules based on each detection time of the pair of the detector modules which approximately coincidentally count annihilation gamma rays and a distance between the pair of detector modules in a state in which a point radiation source including a positron emitting nuclide is installed in each position near a plurality of predetermined detector modules. The image reconstruction unit reconstructs a nuclear medicine image using a time difference between detection times of annihilation gamma rays corrected based on time information calibrated by the calibrator.
