Abstract: The X-ray imager combines a pulsed X-ray source with a time-sensitive X-ray detector to provide a measure of ballistic photons with a reduction of scattered photons. The imager can provide a comparable contrast-to-noise X-ray image using significantly less radiation exposure than conventional X-ray imagers, notably about half of the radiation.

Abstract: The X-ray imager combines a pulsed X-ray source with a time-sensitive X-ray detector to provide a measure of ballistic photons with a reduction of scattered photons. The imager can provide a comparable contrast-to-noise X-ray image using significantly less radiation exposure than conventional X-ray imagers, notably about half of the radiation.

Abstract: An image reconstruction system and method based on image projection data collected by an imaging system having N tubes of response (TORs) having N? axial translation symmetries and N? in-plane rotation symmetries between the TORs. A system matrix mapping image projection data to pixels of an image is used, where the pixels are positioned according to a polar or cylindrical coordinate grid. During image reconstruction, matrix-vector computations are performed between the system matrix and vectors containing image estimates or image projection estimates. The matrix-vector computations are accelerated by structuring the system matrix coefficients, image vectors, and projection measurement vectors in such a way that symmetric data is stored in contiguous memory locations.

Abstract: The present disclosure relates to a method and an apparatus for identifying line-of-responses (LOR) of photons. A radiation detection machine measures the photons. LOR identification errors are then mitigated using pattern recognition of the measurements. In some embodiments, the photons may comprise positron annihilation photons, each position annihilation photon being associated with one or more scattered photons. In yet some embodiments, pattern recognition may be implemented in a neural network.

Abstract: An image reconstruction system and method based on image projection data collected by an imaging system having N tubes of response (TORs) having N? axial translation symmetries and N? in-plane rotation symmetries between the TORs. A system matrix mapping image projection data to pixels of an image is used, where the pixels are positioned according to a polar or cylindrical coordinate grid. During image reconstruction, matrix-vector computations are performed between the system matrix and vectors containing image estimates or image projection estimates. The matrix-vector computations are accelerated by structuring the system matrix coefficients, image vectors, and projection measurement vectors in such a way that symmetric data is stored in contiguous memory locations.

Abstract: An iterative image reconstruction method used with an imaging system that generates projection data, the method comprises: collecting the projection data; choosing a polar or cylindrical image definition comprising a polar or cylindrical grid representation and a number of basis functions positioned according to the polar or cylindrical grid so that the number of basis functions at different radius positions of the polar or cylindrical image grid is a factor of a number of in-plane symmetries between lines of response along which the projection data are measured by the imaging system; obtaining a system probability matrix that relates each of the projection data to each basis function of the polar or cylindrical image definition; restructuring the system probability matrix into a block circulant matrix and converting the system probability matrix in the Fourier domain; storing the projection data into a measurement data vector; providing an initial polar or cylindrical image estimate; for each iteration; reca

Abstract: A digital method and system allowing crystal identification in radiation detector machines is described. The crystal identification is based on recognition of radiation detector signal shape through discrimination of detector signal's dynamic characteristics. The digital method is based on recursive and non-recursive algorithms, such as adaptive filtering combined or not with quantization methods. These digital algorithms, commonly used in other engineering applications, were modified and tailored for radiation detection. Although the method was specially designed for crystal identification measurement, which is exemplified here, it can effectively recognize the detector signal shape in any radiation detection context.

Abstract: An iterative image reconstruction method used with an imaging system that generates projection data, the method comprises: collecting the projection data; choosing a polar or cylindrical image definition comprising a polar or cylindrical grid representation and a number of basis functions positioned according to the polar or cylindrical grid so that the number of basis functions at different radius positions of the polar or cylindrical image grid is a factor of a number of in-plane symmetries between lines of response along which the projection data are measured by the imaging system; obtaining a system probability matrix that relates each of the projection data to each basis function of the polar or cylindrical image definition; restructuring the system probability matrix into a block circulant matrix and converting the system probability matrix in the Fourier domain; storing the projection data into a measurement data vector; providing an initial polar or cylindrical image estimate; for each iteration; reca

Abstract: A digital method and system allowing crystal identification in radiation detector machines is described. The crystal identification is based on recognition of radiation detector signal shape through discrimination of detector signal's dynamic characteristics. The digital method is based on recursive and non-recursive algorithms, such as adaptive filtering combined or not with quantization methods. These digital algorithms, commonly used in other engineering applications, were modified and tailored for radiation detection. Although the method was specially designed for crystal identification measurement, which is exemplified here, it can effectively recognize the detector signal shape in any radiation detection context.