Abstract: A compensating current is applied at one or more points in a signal processing path to compensate for one or both of a dark or offset current present in an input signal. In certain implementations, the dark or offset current is present in a signal generated by a photomultiplier device. The dark or offset current may be monitored in an output of the signal processing path and, the monitoring being used to determine how much compensation is needed in the signal processing path and to allocate where in the signal processing path the compensation current will be applied.

Abstract: Methods and systems for signal communication in gamma ray detectors are provided. One gamma ray detector includes a scintillator block having a plurality of scintillator crystals and a plurality of light sensors coupled to the scintillator crystals and having a plurality of microcells. Each of the plurality of light sensors has a first set of signal traces connected to the microcells and a second set of signal traces connected along the first set of signal traces and together forming a signal path to a summing signal trace. Each of the plurality of light sensors also has a pin-out connected to the summing signal trace.

Abstract: Methods and systems for signal communication in gamma ray detectors are provided. One gamma ray detector includes a scintillator block having a plurality of scintillator crystals and a plurality of light sensors coupled to the scintillator crystals and having a plurality of microcells. Each of the plurality of light sensors have a local summing point in each of a plurality of signal summing regions, wherein the local summing points are connected to the plurality of microcells. The plurality of light sensors also each include a main summing point connected to the plurality of local summing points, wherein the main summing point is located a same distance from each of the local summing points.

Abstract: A method for gain calibration of a gamma ray detector includes measuring signals generated by one or more light sensors of a gamma ray detector, generating one or more derived curves using the measured signals as a function of bias voltage and identifying a transition point in the one or more derived curves. The method also includes determining a breakdown voltage of the one or more light sensors using the identified transition point and setting a bias of the one or more light sensors based on the determined breakdown voltage.

Abstract: Methods and systems for signal communication in gamma ray detectors are provided. One gamma ray detector includes a scintillator block having a plurality of scintillator crystals and a plurality of light sensors coupled to the scintillator crystals and having a plurality of microcells. Each of the plurality of light sensors has a first set of signal traces connected to the microcells and a second set of signal traces connected along the first set of signal traces and together forming a signal path to a summing signal trace. Each of the plurality of light sensors also has a pin-out connected to the summing signal trace.

Abstract: Methods and systems for gain calibration of a gamma ray detector are provided. One method includes measuring signals generated by one or more light sensors of a gamma ray detector, generating one or more derived curves using the measured signals as a function of bias voltage and identifying a transition point in the one or more derived curves. The method also includes determining a breakdown voltage of the one or more light sensors using the identified transition point and setting a bias of the one or more light sensors based on the determined breakdown voltage.

Abstract: A Positron Emission Tomography (PET) detector assembly includes a cold plate having a first side and an opposite second side, the cold plate being fabricated from a thermally conductive and electrically non-conductive material, a plurality of PET detector units coupled to the first side of the cold plate, and a readout electronics section coupled to the second side of the cold plate. A radio frequency (RF) body coil assembly and a dual-modality imaging system are also described herein.

Abstract: A method and system for determining timing recovery information in a positron emission tomography (PET) system. One method includes determining energy information from pairs of light sensors of detectors of the TOF PET system, determining timing information from the pairs of light sensors of the detectors of the TOF PET system and calculating timing recovery information using the determined energy and timing information.

Abstract: A method and apparatus for producing a PET image of a tissue using a PET scanner that includes scintillation crystals and detectors. A first crystal group including a first subset of crystals is formed, and a second crystal group including a second subset of the crystals is formed. The crystals in the first crystal group are different from crystals in the second crystal group A first beam striking one or more crystals of the first crystal group is converted to a first electrical signal, while a second beam striking one or more crystals of the second crystal group is converted to a second electrical signal, wherein the second beam is scattered from the first beam. The second electrical signal is corrected using a correction factor derived from at least one of a first and second timing relationships to compensate for energy in the second signal scattered from the first signal. An image of the tissue is created using the corrected second electrical signal.

Abstract: A method for producing a PET image of a tissue using a PET scanner, the scanner comprising a plurality of scintillation crystals (70X/75X) and a plurality of detectors (71X/76X).

Abstract: A medical imaging system is provided including a positron emission tomography (PET) imaging apparatus and a computed tomography (CT) imaging apparatus. The CT imaging apparatus includes a rotatable gantry. A radioactive source loader is attached to the rotatable gantry to rotate therewith. The radioactive source loader further includes a radioactive source to calibrate the PET imaging apparatus.