In a combined scanner, a main magnet (20) and magnetic field gradient coils (28) housed in or on a scanner housing (12, 18) acquires spatially encoded magnetic resonances in an imaging region (14). Solid state radiation detectors (50, 50', 50'') disposed in or on the scanner housing are arranged to detect gamma rays emitted from the imaging region. Time-of-flight positron emission tomography (TOF-PET) processing (52, 54, 58, 60, 62) determines localized lines of response based on (i) locations of substantially simultaneous gamma ray detections output by the radiation detectors and (ii) a time interval between said substantially simultaneous gamma ray detections. TOF-PET reconstruction processing (64) reconstructs the localized lines of response to produce a TOF-PET image. Magnetic resonance imaging (MRI) reconstruction processing (44) reconstructs the acquired magnetic resonances to produce an MRI image.