1. A method of acquiring image data with an imaging system, comprising: positioning a movable single x-ray source tube in a housing, wherein the housing is connected to a mobile cart operable to move the housing from a first operating room to a second operating room; powering the single x-ray source tube with a first power source having a first power characteristic to emit x-rays at a first selected position relative to the patient; powering the single x-ray source tube with a second power source having a second power characteristic different from the first power characteristic to emit x-rays relative to the first selected position relative to the patient; acquiring image data relative to the first selected position at both the first power characteristic and the second power characteristic; and executing instructions with a processor to reconstruct a three-dimensional model of a portion of the patient at the first selected position with an algebraic iterative technique.