Abstract: A Compton camera for medical imaging is divided into segments with each segment including part of the scatter detector, part of the catcher detector, and part of the electronics. The different segments may be positioned together to form the Compton camera arcing around part of the patient space. By using segments, any number of segments may be used to fit with a multi-modality imaging system.

Abstract: A Compton camera for medical imaging is divided into segments with each segment including part of the scatter detector, part of the catcher detector, and part of the electronics. The different segments may be positioned together to form the Compton camera arcing around part of the patient space. By using segments, any number of segments may be used to fit with a multi-modality imaging system.

Abstract: For count loss correction, the capability of the discriminator, measured periodically, to detect an event is identified. Rather than inserting an actual event or a signal emulating an actual event for discrimination, the capability to discriminate is tested by a virtual injection. The count loss may be directly measured without causing extra actual discrimination by the discriminator. Direct measurement with virtual testing may avoid loss of accuracy due to time and use-case variation.

Abstract: Disclosed herein is a method for estimating count loss in a gamma camera comprising injecting a synthetic pulse at a given rate into a data stream emanating from a photo detector; integrating the synthetic pulse into the data stream to form an integrated data stream; determining a number of synthetic pulses from the data stream that pass onto a final image; and determining the count loss from the Equation (2) Percent ? ? Count ? ? Loss = ( Number ? ? of ? ? pulses ? ? introduced - Number ? ? of ? ? pulses ? ? detected ) × 100 Number ? ? of ? ? pulses ? ? ? introduced .

Abstract: For count loss correction, the capability of the discriminator, measured periodically, to detect an event is identified. Rather than inserting an actual event or a signal emulating an actual event for discrimination, the capability to discriminate is tested by a virtual injection. The count loss may be directly measured without causing extra actual discrimination by the discriminator. Direct measurement with virtual testing may avoid loss of accuracy due to time and use-case variation.

Abstract: System includes a signal processing system to receive a digital signal associated with first scintillation events and to determine a value associated with each of the events, a backend processing system to receive the values, determine an event rate based on the received values, determine whether the event rate is greater than a first threshold, and, if the event rate is greater, transmit a first instruction to increase a consecutive event dump level, and an event management control to receive the first instruction to increase the consecutive event dump level, increase the consecutive event dump level in response to the received instruction, determine a number of consecutive scintillation events of detected second scintillation events, determine to dump the consecutive scintillation events based on a comparison between the number of consecutive scintillation events and the consecutive event dump level, and transmit a second instruction to dump the consecutive scintillation events.

Abstract: Disclosed herein is a method for estimating count loss in a gamma camera comprising injecting a synthetic pulse at a given rate into a data stream emanating from a photo detector; integrating the synthetic pulse into the data stream to form an integrated data stream; determining a number of synthetic pulses from the data stream that pass onto a final image; and determining the count loss from the Equation (2) Percent ? ? Count ? ? Loss = ( Number ? ? of ? ? pulses ? ? introduced - Number ? ? of ? ? pulses ? ? detected ) × 100 Number ? ? of ? ? pulses ? ? ? introduced .

Abstract: A magnetic resonance and positron emission tomography (MR-PET) hybrid scanner workflow for providing a scout scan (topogram) of a patient includes (a) positioning the patient in the MR-PET hybrid scanner; (b) referencing the patient to the scanner's field of view; (c) specifying the patient parameters for MR and PET hybrid topogram scan; (d) performing hybrid MR-PET topogram scan and acquiring MR topogram scan data and PET topogram scan data simultaneously; and (e) reconstructing the MR and PET topogram scan images in real-time; and (f) presenting the topogram san images as a fused topogram data set.

Abstract: A method and apparatus for compensating for the presence of a magnetic field during medical imaging are disclosed. Gamma photons are acquired at a detector. An orientation of the detector (e.g., relative to the surface of the earth) corresponding to the acquisition is determined. Based on the determined detector orientation, one or more compensation value(s) are determined from a memory of a computer, e.g., based on interpolation, parametric computation, or a look-up table. Energy signal variation of a detected signal due to the detector orientation is compensated for by applying the determined compensation value.

Abstract: Timing in a medical imaging system. The system comprises a magnetic resonance imaging (MRI) subsystem and a non-MRI subsystem. Operation of the non-MRI subsystem involves a timing signal within a radio frequency (RF) cabin of the MRI subsystem. Basing each non-MRI subsystem timing signal on a time base common between the MRI subsystem and the non-MRI subsystem. The non-MRI subsystem can be a medical imaging subsystem. The non-MRI medical imaging subsystem can be a positron emission tomography (PET) subsystem. Each non-MRI subsystem timing signal that based on the common time base can be created using the same model of equipment used for creating timing signals in the MRI subsystem. At least one stage of the non-MRI subsystem timing signal based on the common time base can be created using the same equipment used for creating timing signals in the MRI subsystem.

Abstract: A printed circuit board (PCB) assembly of a data processing unit for an integrated magnetic resonance (MR) and positron emission tomography (PET) system, the PCB assembly includes a plurality of PCB layers disposed in a stacked arrangement, first and second PET signal processing circuits carried by a first layer of the plurality of PCB layers, first and second ground plane structures carried by a second layer of the plurality of PCB layers and configured relative to the first and second PET signal processing circuits, respectively, and a ground partition that separates the first PET signal processing circuit from the second PET signal processing circuit on the first layer. The ground partition extends through the first layer to provide electromagnetic interference (EMI) shielding between the first and second PET signal processing circuits.

Abstract: An integrated magnetic resonance (MR) and positron emission tomography (PET) system includes an MR scanner including a magnet that defines an opening in which a subject is positioned, a set of PET detectors disposed about the opening, a plurality of data processing units each electrically connected with a respective one or more of the PET detectors of the set of PET detectors, and a plurality of power supply modules, each power supply module being operable to generate a DC power supply for different groups of one or more of the data processing units. Each power supply module is discrete from the other power supply modules.

Abstract: A method and apparatus for compensating for the presence of a magnetic field during medical imaging are disclosed. Gamma photons are acquired at a detector. An orientation of the detector (e.g., relative to the surface of the earth) corresponding to the acquisition is determined. Based on the determined detector orientation, one or more compensation value(s) are determined from a memory of a computer, e.g., based on interpolation, parametric computation, or a look-up table. Energy signal variation of a detected signal due to the detector orientation is compensated for by applying the determined compensation value.

Abstract: A positron emission tomography (PET) system includes a PET detector configured to generate energy signals indicative of a set of events at the PET detector, a first discriminator coupled to the PET detector and configured to generate a primary timing signal in response to a primary event of the set of events, a second, derivative-based discriminator coupled to the PET detector and configured to generate a pileup timing signal in response to a piled-up event of the set of events, and a logic circuit to gate the primary and pileup timing signals of the first and second discriminators.

Abstract: A system includes a gantry, a first positron emission tomography (PET) section including a first detector ring oriented about an axis, and a second PET section supported by the gantry and including a second detector ring oriented about the axis. The gantry is adjustable to move the second PET section relative to the first PET section.

Abstract: A system and tuning method to collaboratively calibrate high voltage DAC values and Photomultiplier Tube DAC values of photomultiplier tubes of a gamma camera so that the detector produces a valid energy spectrum over the entire detector surface. A method for tuning a gamma camera having a plurality of photosensors, exposes the photosensors to scintillation photons corresponding to nuclear radiation of known energy; measures an energy output corresponding to each specific photosensor; calculates an average enemy output of all photosensors in the camera; collaboratively adjusts a DAC value corresponding to a voltage applied to a specific photosensor and a DACHV value corresponding to a high voltage applied to the camera based on the calculated average energy, energy output of each photosensor, and a target energy value corresponding to said known energy; and repeats the calibration until convergence is achieved between the average energy, energy output, and target energy.

Abstract: An integrated magnetic resonance (MR) and positron emission tomography (PET) system includes an MR scanner including a magnet that defines an opening in which a subject is positioned, a set of PET detectors disposed between the magnet and the opening, and a plurality of data processing units, each data processing unit being configured for communication with a respective one or more of the PET detectors of the set of PET detectors. The plurality of data processing units are positioned along a side of the MR scanner not having the opening.

Abstract: Using standard or “off the shelf” cable to interconnect between the PET block detector and the detector circuit may save substantial costs given the number of PMTs in a PET system. Given space constraints, simple maintenance with reduced risk of disturbing cabling is desired, making ongoing use of standard cabling without adding further cabling desired. To implement digital gain control, a further communication is provided between the PET detector block and the detector circuit. Since the standard cable may not have additional wires for such communications and to reduce timing degradation, the PMT signals are combined, such as generating position and energy signals at the PET detector block. The four PMT signals are reduced to three signals without reduction in function, allowing a fourth twisted pair of wires in a CAT5 cable to be used for digital gain control.

Abstract: A data processing unit for an integrated magnetic resonance (MR) and positron emission tomography (PET) system includes an RF shield housing, a first input port in the RF shield housing configured to receive a PET detector signal, a first filter disposed in the RF shield housing, in communication with the first input port, and configured to remove MR noise from the PET detector signal, a second input port in the RF shield housing configured to receive DC power, a second filter disposed in the RF shield housing, in communication with the second input port, and configured to remove the MR noise from the DC power, and a signal processing circuit disposed in the RF shield housing and powered by the DC power, the signal processing circuit including an analog-to-digital converter to digitize the PET detector signal.

Abstract: An integrated magnetic resonance (MR) and positron emission tomography (PET) system includes an MR scanner including a magnet that defines an opening in which a subject is positioned, a set of PET detectors disposed between the opening and the magnet, and a plurality of data processing units, each data processing unit being configured for communication with a respective one or more of the PET detectors of the set of PET detectors. Each data processing unit includes an RF shield housing, and the RF shield housings of the plurality of data processing units are disposed in a symmetrical arrangement relative to the opening.