Patent ID: 7339176
Filing Date: 2008-03-04
Classification: G01T

Abstract:
1. A single photon counting radiation detector camera head for gamma ray imaging comprising an array of multiple removable pixelated detector modules mounted in said head for producing an imaging focal plane having pixels to produce a signal, said modules including a pixilated detector, selected from a group including semiconductors made of CdZnTe and CdTe, and an ASIC having inputs, said inputs being electrically connected to each of said pixels for processing the signal produced by said pixels, said modules comprising said pixels and having side walls, said modules being mounted such that a gap exists between said side walls of an adjacent pair of said modules, said pixels on said modules not located adjacent to a side wall have first lateral dimensions, and at least some of said pixels disposed along said side walls have second lateral dimensions, wherein said second lateral dimension is smaller than said first lateral dimension by an amount that is equal to half of the width of said gap, wherein the mid-line areas between said pixels of said modules suffer from charge sharing effect, wherein said mid-line areas and said gap between said modules are essentially useless areas for imaging by single photon counting, wherein said camera head also comprises a single collimator unit in front of said imaging plane and over multiple said modules in said imaging focal plane, said collimator having multiple holes that are arranged in a constant pitch across said imaging focal plane that is equal to said first lateral dimension and said holes being spaced by septa, said septa being arranged along mutually perpendicular axes, and wherein said single collimator unit is registered over said pixels of multiple said modules in said imaging focal plane such that said septa of said collimator are substantially aligned with said useless areas for overlapping the shadowing of said septa with said useless areas to obtain optimum camera sensitivity for said imaging by single photon counting.