1. An imaging system for imaging a region of interest (ROI) of a subject, the system comprising: at least one orientator; at least one translator; at least one detector, coupled to the orientator and to the translator; and a control unit, which is configured to: during a first portion of an image acquisition procedure, drive the translator to position the detector in a first position, and, while the detector is thus positioned, drive the orientator to orient the detector in distinct angular orientations with respect to the ROI, by orienting the detector at only a portion of the distinct angular orientations during an initial sweep of the detector, and at remaining distinct angular orientations during a subsequent sweep of the detector, and during a second portion of the image acquisition procedure, drive the translator to position the detector in a second position, and, while the detector is thus positioned, drive the orientator to orient the detector in distinct angular orientations with respect to the ROI.