Abstract: Various devices, systems, and methods for performing personalized dosimetry of a patient receiving a radiopharmaceutical are described. In an example method, anatomic data is generated by performing a computed tomography (CT) scan on the patient when they are lying down and wearing a garment. Based on the anatomic data, locations of organs of the patient are determined with respect to one or more fiducial markers integrated with the garment. Detectors for detecting photons from a radiopharmaceutical are placed on the garment based on locations of the organs. Subsequently, the patient may be administered a dose of the radiopharmaceutical. When the patient wears the garment, the detectors may detect photons released from the decaying radiopharmaceutical that is distributed in the organs. The radiation dosage to the organs may be determined based on the detected photons.

Abstract: Various noncollimated single photon emission computed tomography (SPECT) technologies are described herein. An example device includes an array of detectors configured to detect a flux of first photons transmitted from a field of view (FOV) over time. The device also includes an attenuator disposed between the array of detectors and the FOV. The attenuator is configured to move over time and to attenuate second photons emitted from the source. In various implementations, the attenuator is not a collimator. Based on the fluxes of the first photons detected by the detectors, and the position of the attenuator over time, an imaging system may be configured to generate an image of the FOV.

Abstract: Various noncollimated single photon emission computed tomography (SPECT) technologies are described herein. An example device includes an array of detectors configured to detect a flux of first photons transmitted from a field of view (FOV) over time. The device also includes an attenuator disposed between the array of detectors and the FOV. The attenuator is configured to move over time and to attenuate second photons emitted from the source. In various implementations, the attenuator is not a collimator. Based on the fluxes of the first photons detected by the detectors, and the position of the attenuator over time, an imaging system may be configured to generate an image of the FOV.

Abstract: A garment for detecting radiation washout (e.g., radioactivity concentrations) in organs includes a covering that wraps around and is secured to the body. The covering permits positron emission tomography-computed tomography (PET/CT) imaging of the body through the covering. The garment includes guides formed from a material that is visible in a computed tomography (CT) image of the garment, such that the guides are visible in CT images of user organs that the garment overlies. A plurality of radiation detectors are attached to the covering in a configuration customized for the body. A wiring system connects the plurality of radiation detectors to a power and data control system that is configured to transmit data from the garment to a remote service provider.

Abstract: A method for calibrating a nuclear medicine tomography detector module using principal component analysis is based on the idea that calibration beam data lies on a one-dimensional path within the higher dimensional dataspace of output data. The module includes a weighted multiplexing circuit that generates a small number of multiplexed signals for each photon event. Calibration data for the module is generated and analyzed using several iterations of principal component analyses, to filter scattering events, noise, and other spurious signals. The direction of depth-of-interaction information has been found in the high-dimensional dataspace to be indicated by the primary principal component of the calibration data. The primary principal components, principal components from filtered datasets, intermediate thresholds, and DOI or inner product values are recorded for calibrating the module.

Abstract: A method for calibrating a nuclear medicine tomography detector module using principal component analysis is based on the idea that calibration beam data lies on a one-dimensional path within the higher dimensional dataspace of output data. The module includes a weighted multiplexing circuit that generates a small number of multiplexed signals for each photon event. Calibration data for the module is generated and analyzed using several iterations of principal component analyses, to filter scattering events, noise, and other spurious signals. The direction of depth-of-interaction information has been found in the high-dimensional dataspace to be indicated by the primary principal component of the calibration data. The primary principal components, principal components from filtered datasets, intermediate thresholds, and DOI or inner product values are recorded for calibrating the module.

Abstract: A radiation detector is disclosed that includes a scintillation crystal and a plurality of photodetectors positioned to detect low-energy scintillation photons generated within the scintillation crystal. The scintillation crystals are processed using subsurface laser engraving to generate point-like defects within the crystal to alter the path of the scintillation photons. In one embodiment, the defects define a plurality of boundaries within a monolithic crystal to delineate individual detector elements. In another embodiment, the defects define a depth-of-interaction boundary that varies longitudinally to vary the amount of light shared by neighboring portions of the crystal. In another embodiment the defects are evenly distributed to reduce the lateral spread of light from a scintillation event. Two or more of these different aspects may be combined in a single scintillation crystal.

Abstract: A radiation detector is disclosed that includes a scintillation crystal and a plurality of photodetectors positioned to detect low-energy scintillation photons generated within the scintillation crystal. The scintillation crystals are processed using subsurface laser engraving to generate point-like defects within the crystal to alter the path of the scintillation photons. In one embodiment, the defects define a plurality of boundaries within a monolithic crystal to delineate individual detector elements. In another embodiment, the defects define a depth-of-interaction boundary that varies longitudinally to vary the amount of light shared by neighboring portions of the crystal. In another embodiment the defects are evenly distributed to reduce the lateral spread of light from a scintillation event. Two or more of these different aspects may be combined in a single scintillation crystal.

Abstract: A radiation detector is disclosed that includes a scintillation crystal and a plurality of photodetectors positioned to detect low-energy scintillation photons generated within the scintillation crystal. The scintillation crystals are processed using subsurface laser engraving to generate point-like defects within the crystal to alter the path of the scintillation photons. In one embodiment, the defects define a plurality of boundaries within a monolithic crystal to delineate individual detector elements. In another embodiment, the defects define a depth-of-interaction boundary that varies longitudinally to vary the amount of light shared by neighboring portions of the crystal. In another embodiment the defects are evenly distributed to reduce the lateral spread of light from a scintillation event. Two or more of these different aspects may be combined in a single scintillation crystal.

Abstract: A method for estimating a line or response in a positron emission tomography scanner having depth of interaction estimation capability. The method utilizes information from both detector modules detecting a coincident event. A joint probability density function combining factors accounting for intermediate Compton scattering interactions and/or a final interaction that may be either a Compton scattering interaction or photoelectric absorption is calculated. In a preferred embodiment, a Bayesian estimation scheme is used to integrate the PDF for all permutations of the measured signal pairs, and the permutation with the largest joint probability is selected to construct the estimated line of response.

Abstract: A method is provided for determining the three-dimensional position of an interaction location within a scintillating crystal at which an high-energy photon produces a plurality of scintillation photons. The method includes the use of a sensor-on-entrance-surface photodetector device to determine a distribution pattern of the scintillation photons in the crystal.

Abstract: Improved processing electronic hardware are disclosed that facilitate the efficient processing of PET system data, while enhancing accuracy and compatibility of PET systems with other analytical methods (e.g., magnetic resonance imaging). Improvements include the use of an application-specific integrated circuit (ASIC) for summing, by row, column, and diagonal, the output signals from an array of photodetectors in the PET system.

Abstract: A method for estimating the start time of an electronic pulse generated in response to a detected event, for example the start time for pulses received in response to photon detection in positron emission tomography, includes providing a detector that detects an external event and generates an electronic analog pulse signal. A composite reference pulse curve is calculated to represent analog pulse signals generated by the detector. Upon receiving an analog pulse signal, it may be filtered, and then digitized, and normalized based on the area of the digital signal. Using at least one point of the normalized digital pulse signal, the composite reference pulse curve shape is used to estimate the pulse start time.

Abstract: A radiation detector is disclosed that includes a scintillation crystal and a plurality of photodetectors positioned to detect low-energy scintillation photons generated within the scintillation crystal. The scintillation crystals are processed using subsurface laser engraving to generate point-like defects within the crystal to alter the path of the scintillation photons. In one embodiment, the defects define a plurality of boundaries within a monolithic crystal to delineate individual detector elements. In another embodiment, the defects define a depth-of-interaction boundary that varies longitudinally to vary the amount of light shared by neighboring portions of the crystal. In another embodiment the defects are evenly distributed to reduce the lateral spread of light from a scintillation event. Two or more of these different aspects may be combined in a single scintillation crystal.

Abstract: A method for estimating a line or response in a positron emission tomography scanner having depth of interaction estimation capability. The method utilizes information from both detector modules detecting a coincident event. A joint probability density function combining factors accounting for intermediate Compton scattering interactions and/or a final interaction that may be either a Compton scattering interaction or photoelectric absorption is calculated. In a preferred embodiment, a Bayesian estimation scheme is used to integrate the PDF for all permutations of the measured signal pairs, and the permutation with the largest joint probability is selected to construct the estimated line of response.

Abstract: A method for estimating the start time of an electronic pulse generated in response to a detected event, for example the start time for pulses received in response to photon detection in positron emission tomography, includes providing a detector that detects an external event and generates an electronic analog pulse signal. A composite reference pulse curve is calculated to represent analog pulse signals generated by the detector. Upon receiving an analog pulse signal, it may be filtered, and then digitized, and normalized based on the area of the digital signal. Using at least one point of the normalized digital pulse signal, the composite reference pulse curve shape is used to estimate the pulse start time.

Abstract: Improved processing electronic hardware are disclosed that facilitate the efficient processing of PET system data, while enhancing accuracy and compatibility of PET systems with other analytical methods (e.g., magnetic resonance imaging).

Abstract: A method for estimating the start time of an electronic pulse generated in response to a detected event, for example the start time for pulses received in response to photon detection in positron emission tomography, includes providing a detector that detects an external event and generates an electronic analog pulse signal. A parameterized ideal curve shape is selected to represent analog pulse signals generated by the detector. Upon receiving an analog pulse signal, it may be filtered, and then digitized, and normalized based on the area of the digital signal. Using at least one point of the normalized digital pulse signal, a curve from the parameterized ideal curve shape is selected, that best represents the received analog pulse signal, and the selected curve is used to estimate the pulse start time.

Abstract: A method is provided for determining the three-dimensional position of an interaction location within a scintillating crystal at which an high-energy photon produces a plurality of scintillation photons. The method includes the use of a sensor-on-entrance-surface photodetector device to determine a distribution pattern of the scintillation photons in the crystal.

Abstract: A method for estimating the start time of an electronic pulse generated in response to a detected event, for example the start time for pulses received in response to photon detection in positron emission tomography, includes providing a detector that detects an external event and generates an electronic analog pulse signal. A parameterized ideal curve shape is selected to represent analog pulse signals generated by the detector. Upon receiving an analog pulse signal, it may be filtered, and then digitized, and normalized based on the area of the digital signal. Using at least one point of the normalized digital pulse signal, a curve from the parameterized ideal curve shape is selected, that best represents the received analog pulse signal, and the selected curve is used to estimate the pulse start time.