A positron emission tomography (PET) apparatus according to an embodiment includes a plurality of PET detector rings (101, 601, 701, 901, 1001, 1101) and a processing unit (307). The plurality of PET detector rings (101, 601, 701, 901, 1001, 1101) is configured to form a bore in which a subject is placed, and to be adjustable in position in an axial direction, the bore defining a field of view (FOV) of the apparatus. The processing unit 307) is configured to obtain information regarding a PET scan mode, and to adjust, based on the information regarding the PET scan mode, position of each of the plurality of PET detector rings (101, 601, 701, 901, 1001, 1101) from a first position to a second position in the axial direction.
POSITRON EMISSION TOMOGRAPHY APPARATUS, METHOD AND COMPUTER-READABLE STORAGE MEDIUM