Abstract:
The present application relates generally to silicon photomultiplier (SiPM) detector arrays. In one aspect, there is a system including an array of cells each including a single-photon avalanche diode (SPAD) reverse-biased above a breakdown voltage of the SPAD. Each cell may further include trigger logic connected to the SPAD, and configured to output a trigger signal indicating whether the SPAD is in breakdown. Each cell may still further include a conditional recharge circuit configured to recharge the SPAD conditional upon both (i) the recharge circuit applying the recharge signal to the cell and (ii) the trigger signal output by the trigger logic of the cell indicating the SPAD of the cell is in breakdown.
Abstract:
The present application relates generally to silicon photomultiplier (SiPM) detector arrays. In one aspect, there is a system including an array of cells each including a single-photon avalanche diode (SPAD) reverse-biased above a breakdown voltage of the SPAD. The system may further include a trigger network configured to generate pulses on a trigger line in response to SPADs of the array undergoing breakdown. The system may still further include a pulse-width filter configured to block pulses on the trigger line whose pulse width is less than a threshold width.
Abstract:
The present invention relates to a calibration method for a gamma ray detector (100) including a pixelated scintillator array (110) for emitting scintillation photons at photo conversion positions (94) in response to incident gamma rays (90), and a pixelated photodetector array (120) for determining a spatial intensity distribution of the scintillation photons. The present invention bases on the idea that using the concept of optical light sharing of scintillation photons, which are emitted in one element, i.e., one scintillator pixel (112) of the scintillator array (110) and distributed over multiple photodetector pixels (122) of the pixelated photodetector array (120), allows obtaining an estimate for the time skew between adjacent photodetector pixels (122). The present invention further relates to a calibration module (200) for a gamma ray detector (100) including a recorder (210) and a processing module (220) for performing the function of the above-explained method. Still further, the present invention relates to a gamma ray detector (100) as well as to a medical imaging device (50) comprising this gamma ray detector (100).
Abstract:
The invention relates to a gamma radiation detector that provides compensation for the parallax effect. The gamma radiation detector includes a plurality of scintillator elements, a planar optical detector array, and a pinhole collimator that includes a pinhole aperture. Each scintillator element has a gamma radiation receiving face and an opposing scintillation light output face. The gamma radiation receiving face of each scintillator element faces the pinhole aperture for generating scintillation light in response to gamma radiation received from the pinhole aperture. The scintillator elements are arranged in groups. Each group has a group axis that is aligned with the pinhole aperture and is perpendicular to the radiation receiving face of each scintillator in that group. The scintillation light output faces of each of the scintillator elements are in optical communication with the planar optical detector array.
Abstract:
An anti-scatter device (ASG) filled with a filler material. The filler material (202) has an acoustic impedance that corresponds to that of human or animal tissue. Furthermore a hybrid X-ray/ultrasound imager (IM) including such an anti-scatter GA device (ASG).
Abstract:
The present invention relates to a calibration method (100) for a gamma ray detector (3, 51) including a scintillator array (5) for emitting scintillation photons at photo conversion positions in response to incident gamma rays and a photodetector array (7) coupled thereto in light-sharing mode for determining a spatial intensity distribution of scintillation photons. The method comprises the steps of recording (S10) spatial intensity distributions of scintillation photons emitted by the scintillator array (5) in response to multiple incident gamma rays, determining (S22) sets of coincidently emitted scintillation photons from the recorded spatial intensity distributions, determining for the sets of coincidently emitted scintillation photons center-of-gravity positions (S24) and cumulative energies (S26), performing (S28) a clustering analysis based on the determined center-of-gravity positions and cumulative energies to obtain clusters (26a, 26b, 33) of gamma ray events attributed to a scintillator array element (15), cumulating (S29) for a cluster (26a, 26b, 33) the spatial intensity distributions to determine a cumulative spatial intensity distribution of scintillation photons emitted in response to incident gamma rays in the scintillator array element and determining (S30) a light matrix including expected spatial intensity distributions of scintillation photons for different scintillator array elements (15) based on the cumulative spatial intensity distributions. The present invention further relates to a calibration module (41) for a gamma ray detector (3, 51) including a recorder (43), a cumulation module (45) and a matrix module (47) for performing the functions of the above-explained method. Still further, the present invention relates to a gamma ray detector (3, 51) as well as to a medical imaging device (49) comprising this gamma ray detector (3, 51).
Abstract:
The present invention relates to a radiation detection device, a system, a method and a computer program product for use in timestamping detected radiation quanta. The device comprises an optical detector pixel array, a timestamp trigger unit and a timing unit. The timestamp trigger unit determines a pixel cell triggering rate for pixel cells within the optical detector pixel array. The timestamp trigger unit causes the timing unit to generate a timestamp based on the pixel cell triggering rate.
Abstract:
In a combined system, a magnetic resonance (MR) scanner includes a magnet configured to generate a static magnetic field at least in a MR examination region from which MR data are acquired. Radiation detectors are configured to detect gamma rays generated by positron-electron annihilation events in a positron emission tomography (PET) examination region. The radiation detectors include electron multiplier elements having a direction of electron acceleration arranged substantially parallel or anti-parallel with the static magnetic field. In some embodiments, the magnet is an open magnet having first and second spaced apart magnet pole pieces disposed on opposite sides of a magnetic resonance examination region, and the radiation detectors include first and second arrays of radiation detectors disposed with the first and second spaced apart magnet pole pieces.