A computer-assisted medical system comprises a fluoroscopic imager having a full scan range in a surgical coordinate space. The system further comprises one or more processors configured to perform a method. The method includes receiving a first fluoroscopic image data set of a patient anatomy. The first fluoroscopic image data set is obtained from the full scan range of the fluoroscopic imager. The method further includes receiving at least one additional fluoroscopic image data set of the patient anatomy from the fluoroscopic imager operating in a constrained range substantially smaller than the full scan range. The method further includes constructing a first planar tomographic image from the first and at least one additional fluoroscopic image data sets.