Patent ID: 7015476

Claim:
A single photon emission computed tomography system for producing multiple tomographic images of the type representing a three-dimensional distribution of a photon-emitting radioisotope, said system comprising: a base including a patient support for supporting a human patient such that a portion of the patient's torso is located in a field of view, a longitudinal axis being defined through the field of view; a detector assembly adjacent the field of view, said detector assembly including a photon-responsive detector operable to detect if a photon strikes the detector, said detector assembly operable to scan for photons emitted from the portion of the patient's torso located in the field of view; a photon-blocking member disposed between the field of view and said detector, said blocking member having an aperture slot defined therethrough for passage of photons aligned with said aperture slot, a line of response being defined from said detector through said aperture; a collimating assembly including a plurality of generally parallel collimating vanes formed of photon-attenuating material, said vanes being spaced apart so as to define a plurality of gaps, the gaps each having a height, each of said vanes having a front edge directed toward the field of view and a back edge directed towards said detector, the front to back depth of each of said vanes being greater than 10 times the height of each of the gaps, said plurality of vanes being disposed between said detector and the field of view such that only photons passing through one of the gaps can travel from the field of view to said detector, said vanes being angled with respect to the aperture slot such that the aperture slot and vanes cooperate to collimate the emitted photons; and a displacement actuator operable to move one of said detector and said photon-blocking member relative to the other of said detector and said photon-blocking member such that said aperture is displaced relative to said detector and the line of response is swept across at least a portion of the field of view.