1. A nuclear medicine (NM) multi-head imaging system comprising: a gantry defining a bore configured to accept an object to be imaged; plural detector units mounted to the gantry, each detector unit defining a corresponding view oriented toward a center of the bore and configured to acquire imaging information over a sweep range corresponding to the corresponding view, the detector units configured to pivot to define the corresponding sweep ranges; and at least one processor operably coupled to at least one of the detector units, the at least one processor configured to: control at least one of the detector units to sweep over an initial range during a primary image acquisition configured to obtain information for reconstructing an image; dynamically determine, during the primary image acquisition, at least one boundary of an angular range of an acquisition range over which the at least one of the detector units is to be swept, wherein the at least one boundary of the angular range of the acquisition range is dynamically determined based on photon counts crossing a threshold during sweeping of the at least one of the detector units, wherein the acquisition range is over a smaller angular range than the initial range, the acquisition range corresponding to an uptake value of the object to be imaged for the at least one of the detector units, and control, during the primary acquisition configured to obtain information for reconstructing the image, the at least one detector unit to sweep over the acquisition range to acquire imaging information over the acquisition range.