Patent ID: 7498582

Claim:
A collimator for use with a detector of nuclear radiation, where the detector has a top surface, comprising: a collimator surface having at least one aperture located in a plane parallel to the top surface, wherein when the collimator is used with the detector, the plane and the top surface are spaced apart by a focal distance f; and at least one collimator septum defining the side wall or walls of the collimator; and means for changing the focal distance f to adjust the focal length of the collimator, wherein the at least one collimator septum is a first septal tube and wherein the means for changing the distance f comprises the first septal tube, a top plate with a centrally located threaded hole, and an aperture tube having male threads, a first opening and a second opening, wherein the aperture tube threadedly engages the threaded hole, and the top plate is secured to one end of the first septum opposite the top surface, and wherein the at least one aperture is the first opening, which is opposite the top surface and changing the relative position of the first opening to the top surface changes the focal distance f.