Abstract: A positron emission tomography (PET) scanner may include a plurality of gamma radiation detector modules arranged to form a detector ring. Each detector module may include an array of elongated scintillation crystals. With respect to the detector ring, each elongated scintillation crystal includes a proximal end-face, two axially oriented lateral faces, two transaxially oriented lateral faces, and a distal end-face radially oriented into the detector ring to receive a gamma photon. An array of photosensors is positioned along a first of the axially oriented lateral faces of each elongated scintillation crystal to detect scintillation photons. A reflective material is positioned on the proximal end-face, the distal end-face, the transaxially oriented lateral faces, and a second of the axially oriented lateral faces of each elongated scintillation crystal to internally reflect scintillation photons.

Abstract: Apparatuses, computer-readable mediums, and methods are provided. In one embodiment, a positron emission tomography (“PET”) detector array is provided which includes a plurality of crystal elements arranged in a two-dimensional checkerboard configuration. In addition, there are empty spaces in the checkerboard configuration. In various embodiments, the empty spaces are filled with passive shielding, transmission source assemblies, biopsy instruments, surgical instruments, and/or electromagnetic sensors. In various embodiments, the crystal elements and the transmission source assemblies simultaneously perform emission/transmission acquisitions.

Abstract: APD-based PET modules are provided for use in combined PET/MR imaging. Each module includes a number of independent, optically isolated detectors. Each detector includes an array of scintillator (e.g. LSO) crystals read out by an array of APDs. The modules are positioned in the tunnel of a MR scanner. Simultaneous, artifact-free images can be acquired with the APD-based PET and MR system resulting in a high-resolution and cost-effective integrated PET/MR system.

Abstract: An automated blood sampling system for PET imaging applications that can be operated in or very near to the field of view (FOV) of an MR scanner, such as in a combined MR/PET imaging system. A radiation detector uses APDs (avalanche photo-diodes) to collect scintillation light from crystals in which the positron-electron annihilation photons are absorbed. The necessary gamma shielding is made from a suitable shielding material, preferably tungsten polymer composite. Because the APDs are quite small and are magnetically insensitive, they can be operated in the strong magnetic field of an MR apparatus without disturbance.

Abstract: A representative positron emission tomography (PET) system includes a positron emission tomography detector having one or more silicon photomultipliers that output silicon photomultipliers signals. The PET system further includes a calibration system that is electrically coupled to the silicon photomultipliers. The calibration system determines a single photoelectron response of the silicon photomultipliers signals and adjusts a gain of the silicon photomultipliers based on the single photoelectron response.

Abstract: A system and method is provided for determining depth of interaction (DOI) information. The system and method includes a detector configured to generate DOI information as a result of radiation emitted from a radiation source. The system and method further includes a plurality of scintillator pixels forming a block, wherein the plurality of scintillator pixels have a first portion and a second portion. A first medium distributed in an alternating pattern of coupling and separation between each of the scintillator pixels in a first portion or second portion of the block is also provided. A plurality of sensors for detecting scintillation events across the plurality of scintillators based on the alternating pattern of coupling and separation between each of the scintillator pixels, wherein DOI information is provided by a position profile of the block, and an image processor for generating a 3 dimensional image from the DOI information are also included.

Abstract: APD-based PET modules are provided for use in combined PET/MR imaging. Each module includes a number of independent, optically isolated detectors. Each detector includes an array of scintillator (e.g. LSO) crystals read out by an array of APDs. The modules are positioned in the tunnel of a MR scanner. Simultaneous, artifact-free images can be acquired with the APD-based PET and MR system resulting in a high-resolution and cost-effective integrated PET/MR system.

Abstract: A system and method are provided for determining the onset of gamma interactions for positron emission tomography (PET) imaging more accurately than with existing techniques. The timing of a sequence of primary trigger events is obtained and used to determine a weighted combination, which mixes the timing information from the various primary trigger events to compute an overall event trigger timing with improved time resolution. Numerical simulations demonstrate that the invention improves time resolution by approximately 10% over state-of-the-art methods. This improved time resolution directly benefits the imaging performance of the PET scanner, especially in time-of-flight (TOF) mode, where a high time resolution directly translates to a reduction in image noise at the same dose—or, alternatively, a reduction of dose to the patient or scan time for the same image quality.

Abstract: Apparatuses, computer-readable mediums, and methods are provided. In one embodiment, a positron emission tomography (“PET”) detector array is provided which includes a plurality of crystal elements arranged in a two-dimensional checkerboard configuration. In addition, there are empty spaces in the checkerboard configuration. In various embodiments, the empty spaces are filled with passive shielding, transmission source assemblies, biopsy instruments, surgical instruments, and/or electromagnetic sensors. In various embodiments, the crystal elements and the transmission source assemblies simultaneously perform emission/transmission acquisitions.

Abstract: Systems and methods for correcting output signals from non-linear photosensors, specifically silicon photomultipliers (SiPMs). SiPMs are used in a PET detector to readout light emissions from LSO scintillator crystals. The non-linear output of the SiPM can distort and compress the energy spectrum which is crucial in PET imaging. The non-linearity effect for inter-crystal scattered events can place an energy event outside of the PET detector energy window, resulting in a rejected event. Systems and methods to correct the SiPM non-linearity for inter-crystal scattered events, so as to be able to obtain the proper energy event and produce an accurate medical image, are disclosed.

Abstract: Apparatuses, computer-readable mediums, and methods are provided. In one embodiment, a positron emission tomography (“PET”) detector array is provided which includes a plurality of crystal elements arranged in a two-dimensional checkerboard configuration. In addition, there are empty spaces in the checkerboard configuration. In various embodiments, the empty spaces are filled with passive shielding, transmission source assemblies, biopsy instruments, surgical instruments, and/or electromagnetic sensors. In various embodiments, the crystal elements and the transmission source assemblies simultaneously perform emission/transmission acquisitions.

Abstract: An apparatus and method to decrease light saturation in a photosensor array and increase detection efficiency uses a light distribution profile from a scintillator-photodetector geometry to configure the photosensor array to have a non-uniform sensor cell pattern, with varying cell density and/or varying cell size and shape. A solid-state photosensor such as a SiPM sensor having such a non-uniform cell structure realizes improved energy resolution, higher efficiency and increased signal linearity. In addition the non-uniform sensor cell array can have improved timing resolution due to improvements in statistical fluctuations. A particular embodiment for such photosensors is in PET medical imaging.

Abstract: The present invention is a Silicon PhotoMulitplier comprising a plurality of photon detection cell clusters each comprising a plurality of avalanche photodiodes connected in parallel, so that the output of each avalanche photodiode is summed together and applied to a cell cluster output. Each of the plurality of cell cluster outputs is connected to one of a plurality of cluster readout circuits, each of which includes an analog to digital converter that converts an analog representation of the total energy received by a photon detection cell cluster to a digital energy signal. A SiPM Pixel reader circuit is connected to the plurality of cluster readout circuits and configured to generate an overall pixel output by digital processing the plurality of digital energy signals received from the plurality of photon detection cell clusters by way of the plurality of cluster readout circuits.

Abstract: Apparatuses, computer-readable mediums, and methods are provided. In one embodiment, a positron emission tomography (“PET”) detector array is provided which includes a plurality of crystal elements arranged in a two-dimensional checkerboard configuration. In addition, there are empty spaces in the checkerboard configuration. In various embodiments, the empty spaces are filled with passive shielding, transmission source assemblies, biopsy instruments, surgical instruments, and/or electromagnetic sensors. In various embodiments, the crystal elements and the transmission source assemblies simultaneously perform emission/transmission acquisitions.

Abstract: A system and method are provided for determining the onset of gamma interactions for positron emission tomography (PET) imaging more accurately than with existing techniques. The timing of a sequence of primary trigger events is obtained and used to determine a weighted combination, which mixes the timing information from the various primary trigger events to compute an overall event trigger timing with improved time resolution. Numerical simulations demonstrate that the invention improves time resolution by approximately 10% over state-of-the-art methods. This improved time resolution directly benefits the imaging performance of the PET scanner, especially in time-of-flight (TOF) mode, where a high time resolution directly translates to a reduction in image noise at the same dose—or, alternatively, a reduction of dose to the patient or scan time for the same image quality.

Abstract: Systems, devices, and methods are provided for more efficient photon detection in nuclear medical imaging. By basing the density of photosensitive microcells in photosensors on a spatial distribution of photons across the array of photosensors, the non-linearity of the photosensors' output pulses can be reduced, and the negative effects of non-uniform distribution of light from a scintillator array can be ameliorated. As a result, the positioning and linearity information of typical photosensors used in nuclear medical imaging can be improved, and better quality images are produced.

Abstract: An apparatus and method to decrease light saturation in a photosensor array and increase detection efficiency uses a light distribution profile from a scintillator-photodetector geometry to configure the photosensor array to have a non-uniform sensor cell pattern, with varying cell density and/or varying cell size and shape. A solid-state photosensor such as a SiPM sensor having such a non-uniform cell structure realizes improved energy resolution, higher efficiency and increased signal linearity. In addition the non-uniform sensor cell array can have improved timing resolution due to improvements in statistical fluctuations. A particular embodiment for such photosensors is in PET medical imaging.

Abstract: Systems and methods for correcting output signals from non-linear photosensors, specifically silicon photomultipliers (SiPMs). SiPMs are used in a PET detector to readout light emissions from LSO scintillator crystals. The non-linear output of the SiPM can distort and compress the energy spectrum which is crucial in PET imaging. The non-linearity effect for inter-crystal scattered events can place an energy event outside of the PET detector energy window, resulting in a rejected event. Systems and methods to correct the SiPM non-linearity for inter-crystal scattered events, so as to be able to obtain the proper energy event and produce an accurate medical image, are disclosed.

Abstract: The present invention is a photodetector including improved photosensors configured of an array of small (sub-millimeter) high-density avalanche photodiode cells utilized to readout a single scintillator. Each photosensor comprises a plurality of avalanche photodiodes cells arranged in an (n×n) array of avalanche photodiode cells (where, n>1) that are coupled to a single scintillation crystal. The overall (n×n) array area as the photosensor is the same as the area of a face of the scintillator and each avalanche photodiode cell has a surface area that is not greater than one square millimeter. The photosensor is also configured to facilitate reading the output of each avalanche photodiode cell in the array. By reading out each small avalanche photodiode cell independently, the noise and capacitance are minimized and thereby provide a more accurate determination of energy and timing.

Abstract: The present invention is a photodetector including improved photosensors configured of an array of small (sub-millimeter) high-density avalanche photodiode cells utilized to readout a single scintillator. Each photosensor comprises a plurality of avalanche photodiodes cells arranged in an (n×n) array of avalanche photodiode cells (where, n>1) that are coupled to a single scintillation crystal. The overall (n×n) array area as the photosensor is the same as the area of a face of the scintillator and each avalanche photodiode cell has a surface area that is not greater than one square millimeter. The photosensor is also configured to facilitate reading the output of each avalanche photodiode cell in the array. By reading out each small avalanche photodiode cell independently, the noise and capacitance are minimized and thereby provide a more accurate determination of energy and timing.