Design and fabrication of lead hexagonal multihole collimators

Two types of sensitive multihole collimators were required for the dynamic study of cerebral circulation using technetium 99m. A description is given of the design and fabrication of parallel holes and well-shielded focusing collimators. The collimators were made of lead foil 0.25mm thick, folded round formers into either parallel sided or tapering hexagonal tubes and then soldered together. Measurements were made of the characteristic isocount curves of both types. (U.K.)