Abstract: A method and apparatus for diagnosing and/or calibrating underperforming pixels in detectors in a small pixelated photon counting CT system utilizes a series of tests on image data acquired in-situ as part of a series of calibration scans in the CT system. Tests are performed on the acquired data to determine the existence of underperforming pixels within the detectors such that the information acquired by those pixels can be replaced by alternate data from surrounding pixels (e.g. by interpolation). The underperforming pixels are stored in “bad” pixel tables and may be specific to a type of image (e.g., spectral or counting) and a specific protocol.

Abstract: A method and apparatus for diagnosing and/or calibrating underperforming pixels in detectors in a small pixelated photon counting CT system utilizes a series of tests on image data acquired in-situ as part of a series of calibration scans in the CT system. Tests are performed on the acquired data to determine the existence of underperforming pixels within the detectors such that the information acquired by those pixels can be replaced by alternate data from surrounding pixels (e.g. by interpolation). The underperforming pixels are stored in “bad” pixel tables and may be specific to a type of image (e.g., spectral or counting) and a specific protocol.

Abstract: According to one embodiment, a photon-counting detector (PCD) includes a plurality of macro-pixels. The plurality of macro-pixels arranged on a semiconductor crystal has a first face and a second face. The first face and the second face are parallel. Each macro-pixel from the plurality of macro-pixels is configured to acquire projection data for generating a reconstructed image. The plurality of macro-pixels each includes at least one large micro-pixel is disposed within the each macro-pixel and at least two small micro-pixels is disposed within the each macro-pixel. Each of the at least two small micro-pixels has a surface area that is less than a surface area of the at least one large micro-pixel.

Abstract: A method and apparatuses are provided to estimate, for two or more detector elements in an array of photon-counting detector elements, respective energy spectra of an X-ray beam incident on the corresponding detector elements from an X-ray source, the energy spectra being estimated by modeling X-ray attenuation as a function of X-ray energy when an X-ray beam is transmitted through a filter and set, for each detector element of the two or more detector elements, a first energy threshold of an energy range that is detected by the each detector element, the first energy threshold of the each detector element being based on the estimated energy spectra of the each detector element.

Abstract: A method and apparatuses are provided to estimate, for two or more detector elements in an array of photon-counting detector elements, respective energy spectra of an X-ray beam incident on the corresponding detector elements from an X-ray source, the energy spectra being estimated by modeling X-ray attenuation as a function of X-ray energy when an X-ray beam is transmitted through a filter and set, for each detector element of the two or more detector elements, a first energy threshold of an energy range that is detected by the each detector element, the first energy threshold of the each detector element being based on the estimated energy spectra of the each detector element.

Abstract: A method and apparatuses are provided to identify and correct partial volume errors (PVEs) in material decomposition of a spectral computed tomography (CT) scan, due to different X-ray trajectories incident on a same macro-pixel passing through different material components (e.g., bone and water). Macro-pixels are virtual crystals generated by aggregating the signals/counts from several smaller actual pixels (i.e., micro-pixels) of a detector array. Thus, when a PVE is identified within a macro-pixel, the separate signals/counts from the micro-pixels can be used for material decomposition, instead of the aggregated signals/counts of the macro-pixel, thereby providing improved spatial resolution of the material components and, at least partial, overcoming the PVE. A measure of the difference between spectrally-resolved counts based a material projection lengths (e.g., from a calibrated lookup table) and the measured counts of the macro-pixel can be used to identify PVEs, e.g.

Abstract: A method and apparatuses are provided to identify and correct partial volume errors (PVEs) in material decomposition of a spectral computed tomography (CT) scan, due to different X-ray trajectories incident on a same macro-pixel passing through different material components (e.g., bone and water). Macro-pixels are virtual crystals generated by aggregating the signals/counts from several smaller actual pixels (i.e., micro-pixels) of a detector array. Thus, when a PVE is identified within a macro-pixel, the separate signals/counts from the micro-pixels can be used for material decomposition, instead of the aggregated signals/counts of the macro-pixel, thereby providing improved spatial resolution of the material components and, at least partial, overcoming the PVE. A measure of the difference between spectrally-resolved counts based a material projection lengths (e.g., from a calibrated lookup table) and the measured counts of the macro-pixel can be used to identify PVEs, e.g.

Abstract: According to one embodiment, a photon-counting detector (PCD) includes a plurality of macro-pixels. The plurality of macro-pixels arranged on a semiconductor crystal has a first face and a second face. The first face and the second face are parallel. Each macro-pixel from the plurality of macro-pixels is configured to acquire projection data for generating a reconstructed image. The plurality of macro-pixels each includes at least one large micro-pixel is disposed within the each macro-pixel and at least two small micro-pixels is disposed within the each macro-pixel. Each of the at least two small micro-pixels has a surface area that is less than a surface area of the at least one large micro-pixel.