Abstract: Disclosed herein is a method for estimating count loss in a gamma camera comprising injecting a synthetic pulse at a given rate into a data stream emanating from a photo detector; integrating the synthetic pulse into the data stream to form an integrated data stream; determining a number of synthetic pulses from the data stream that pass onto a final image; and determining the count loss from the Equation (2) Percent ? ? Count ? ? Loss = ( Number ? ? of ? ? pulses ? ? introduced - Number ? ? of ? ? pulses ? ? detected ) × 100 Number ? ? of ? ? pulses ? ? ? introduced .

Abstract: Disclosed herein is a method for estimating count loss in a gamma camera comprising injecting a synthetic pulse at a given rate into a data stream emanating from a photo detector; integrating the synthetic pulse into the data stream to form an integrated data stream; determining a number of synthetic pulses from the data stream that pass onto a final image; and determining the count loss from the Equation (2) Percent ? ? Count ? ? Loss = ( Number ? ? of ? ? pulses ? ? introduced - Number ? ? of ? ? pulses ? ? detected ) × 100 Number ? ? of ? ? pulses ? ? ? introduced .

Abstract: An improved system and method for tuning individual sensors (e.g., photomultiplier tubes) of a multi-sensor imaging system such as, e.g., a gamma camera having an array of photo-multiplier tubes is provided that produces a uniform response over the entire system. Individual sensors of a multi-sensor imaging system are tuned based explicitly or implicitly on gain characteristics of individual sensors of the multi-sensor imaging system so as to produce a uniform response over the system.

Abstract: A method and apparatus for acquiring total uniformity for a scintillation imaging apparatus are provided. A generic energy (Z) map is first obtained. The generic Zmap is then corrected for linearity by use of a dot pattern. The listmode data is used to construct an energy histogram matrix. A twin Zmap is then obtained by optimizing the lower and upper boundaries of the energy window for each pixel in relation to the average energy over the Center Field of View.

Abstract: A method and system of correcting misalignment effects in reconstructed images of a nuclear medical imaging apparatus includes calculating misalignments of a detector to accommodate for deflections (e.g., gravity induced deflections) of a detector (e.g., a cantilevered detector mounted for rotation movement about a patient) from a fixed coordinate system used for image data acquisition.

Abstract: A method and system for calibrating a scintillation camera includes steps of constructing a pair of generic linearity coefficient (LC) matrices from a representative detector based on measurement of non-linearity; and transforming the pair of generic LC matrices according to measured pinhole locations from a lead mask to generate detector specific LC matrices.

Abstract: Point source responses of pinhole apertures in a non-uniform grid mask used to spatially calibrate a gamma camera can be modeled as a two-dimensional Gaussian model function. Pinhole data from each pinhole location are added together to generate a complete Gaussian model of the flood image from the mask. The Gaussian model then is subjected to global and PMT-based pattern matching with an actual input flood image obtained using the mask, to obtain a transformed Gaussian model that is more accurately aligned with actual pinhole locations of the mask. The transformed Gaussian model then can be used in a peak detection process for calibration images, which are used to develop LC coefficients for the camera.

Abstract: Point source responses of pinhole apertures in a non-uniform grid mask used to spatially calibrate a gamma camera can be modeled as a two-dimensional Gaussian function with a set of seven parameters. The Gaussian parameters can be measured using a surface-fitting algorithm that seeks minimum error in the least squares sense. The process is repeated for data from each pinhole location and the data are added together to generate a complete model of the flood image from the mask, which then can be used in a peak detection process for clinical images.

Abstract: In some preferred embodiments, an apparatus is provided that facilitates correction, such as, e.g., linearity correction, in imaging devices, such as, e.g., scintillation cameras. In preferred embodiments, a mask is implemented that can produce images for locating the actual position of a nuclear event based on its apparent position with high accuracy and reliability. In the preferred embodiments, the mask includes a non-uniform array of apertures that can achieve this goal.

Abstract: A gamma camera includes a number of bar detector strips made of scintillating material, arranged in a stack configuration, where at least one photodetector is coupled to one or both ends of each detector strip, and a slat collimator including a plurality of elongated slats, for collimating each of the bar detector strips to receive gamma photons in only a single dimension. According to another aspect of the invention, a method of obtaining tomographic images of an object includes the steps of obtaining a number of sets of planar integral scintillation event data from the object at a number of azimuth angles of a rotating scintillation detector for each of a number of gantry angles of a gamma camera, and reconstructing the sets of planar integral scintillation event data to form a tomographic image of the object.