Abstract: A method for temporally imaging a cyclic body structure during a predetermined phase of its cycle using a CT scanner of the type having a rotating radiation source. In one embodiment the image or other display is generated using data produced when the radiation source is at a predetermined position when the body structure is in the predetermined phase. The method can be performed by using only data collected when the radiation source is at the predetermined position and the body structure is in the predetermined phase, by stimulating the body structure so the phase of the body structure and location of the radiation source are synchronized, or by controlling the motion of the radiation source so the location of the radiation source and the phase of the body structure are synchronized.