1. A method for calibrating an, imaging system having an array of detector elements arranged with respect to a reference position and having an energy source moving in a pattern to irradiate the array of detector elements, said method comprising: initiating estimated detector positions for the array of detector elements and an estimated motion pattern for the energy source, said estimated detector positions and motion pattern being defined with respect to a reference position in the imaging system; scanning a phantom having pins located at positions in the phantom; calculating estimated pin positions for the pins in the phantom, with respect to the reference position, based on at least one of said estimated detector positions and motion pattern; modifying at least one of said estimated detector positions and pin positions based on at least two of said estimated detector positions, motion pattern and pin positions; determining variation in the motion pattern based on at least one of said estimated detector positions and pin positions; and adjusting said motion pattern for the energy source based on said variation.