Abstract: A method including imaging a first field of view (FOV) of a volume of interest (VOI) that includes a region of interest (ROI) from a first position and imaging the first FOV of the VOI from a second position. The method including receiving a first identification of a first portion of the imaged VOI designating the ROI to be imaged and a second identification of a second portion of the imaged VOI from the second position designating the ROI to be imaged. In response to the first identification, adjusting an aperture of a collimator of an imaging source to a second FOV corresponding to the ROI from the first position and imaging the ROI using the second FOV. In response to the second identification, adjusting the aperture of the collimator to a third FOV corresponding to the ROI from the second position and imaging the ROI using the third FOV.