A positron emission tomography (PET) system includes a memory (18), a subject support (3), a categorizing unit (20), and a reconstruction unit (22). The memory (18) continuously records detected coincident event pairs detected by PET detectors (4). The subject support (3) supports a subject and moves in a continuous movement through a field of view (10) of the PET detectors (4). The categorizing unit (20) categorizes the recorded coincident pairs into each of a plurality of spatially defined virtual frame (14). The reconstruction unit (22) reconstructs the categorized coincident pairs of each virtual frame into a frame image and combines the frame images into a common elongated image.