A whole body PET and CT combined detector and device, comprising a CT scanner frame (4) and a PET detection chamber (5) at the front and the rear along a common central axis. The CT scanner frame (4) is provided with a housing and also has a cylindrical CT scanning channel vertical to the central axis; the PET detection chamber (5) is formed by a plurality of PET detection modules (6, 7) adjacent to each other, and PET detection crystals (10) are all arranged in a direction towards to the chamber, the PET detection chamber (5) is entirely closed or a first opening is formed at the side adjacent to the CT scanner frame (4); each of the PET detection modules (6, 7) is composed of the PET detection crystals (10), a photoelectric sensor array (8), and a light guide (9); and except for the first opening, the cross-sectional areas of all gaps of the PET detection chamber (5) are smaller than the detected surface area of the smallest one of the PET detection crystals (10).

An apparatus is described herein. The apparatus comprises a first modality unit and a second modality unit. The first modality unit is located within a gantry. The second modality unit within the gantry is moveable along an examination axis to be concentric about with the first modality unit such that a field of view of the first modality unit and a field of view of the second modality unit are centered about a single point of interest.

The invention relates to a combined detector (660) comprising a gamma radiation detector (100) and an X-ray radiation detector (661). The gamma radiation detector (100) comprises a gamma scintillator array (101.sub.x, y), an optical modulator (102) and a first photodetector array (103.sub.a, b) for detecting the first scintillation light generated by the gamma scintillator array (101.sub.x, y). The optical modulator (102) is disposed between the gamma scintillator array (101.sub.x, y) and the first photodetector array (103.sub.a, b) for modulating a transmission of the first scintillation light between the gamma scintillator array (101.sub.x, y) and the first photodetector array (103.sub.a, b). The optical modulator (102) comprises at least one optical modulator pixel having a cross sectional area (102′) in a plane that is perpendicular to the gamma radiation receiving direction (104). The cross sectional area of each optical modulator pixel (102′) is greater than or equal to the cross sectional area of each photodetector pixel (103′.sub.a, b).

Systems and methods for tissue discrimination are disclosed. The systems and the methods utilize coded x-ray beams. Transmission signals and scatter signals are utilized to determine tissue properties.

A whole body PET and CT combined detector and device, comprising a CT scanner frame (4) and a PET detection chamber (5) at the front and the rear along a common central axis. The CT scanner frame (4) is provided with a housing and also has a cylindrical CT scanning channel vertical to the central axis; the PET detection chamber (5) is formed by a plurality of PET detection modules (6, 7) adjacent to each other, and PET detection crystals (10) are all arranged in a direction towards to the chamber; the PET detection chamber (5) is entirely closed or a first opening is formed at the side adjacent to the CT scanner frame (4); each of the PET detection modules (6, 7) is composed of the PET detection crystals (10), a photoelectric sensor array (8), and a light guide (9); and except for the first opening, the cross-sectional areas of all gaps of the PET detection chamber (5) are smaller than the detected surface area of the smallest one of the PET detection crystals (10).

Described herein is multiplexing scintillation blocks, called interblock muxing. Specifically, the start of an annihilation event is recorded and assigned a time stamp while the energy of the entire event is recorded separately. All events occurring at a series of multiplexed scintillation blocks are reported to a processor which distinguishes individual events and assigns the start of each event with its corresponding energy, thereby allowing for cheaper and more efficient processing of events during PET imaging.

Systems and methods for tissue discrimination are disclosed. The systems and methods utilize coded x-ray beams. Transmission signals and scatter signals are utilized to determine tissue properties.

A detector, includes a plurality of photomultiplier tubes each having an anode configured to generate an anode output signal and a frequency domain detector interface including a plurality of frequency domain coupling circuits. Each of the plurality of frequency domain coupling circuits is configured to receive the anode output signal from one of the plurality of photomultiplier tubes and pickoff one of a high-frequency component or a low-frequency component. Each of the plurality of frequency domain coupling circuits is further configured to generate a pass-through signal comprising a first of the high-frequency component or the low-frequency component.

A dual mode radiation detector includes an x-ray detector layer configured to convert incident x-ray radiation into x-ray electrical data, where the x-ray detector forms an incident face of the dual mode radiation detector. The dual mode radiation detector further includes a collimator disposed below the x-ray detector layer, and a gamma photon detector layer disposed below the collimator to convert incident gamma photons into gamma photon electrical data.

The invention relates to a combined imaging detector (110) for the detection of x-ray and gamma quanta. The combined imaging detector (110) is adapted for simultaneous detection of gamma and x-ray quanta. The combined imaging detector (110) includes an x-ray anti-scatter grid (111), a layer of x-ray scintillator elements (112), a first photodetector array (113), a layer of gamma scintillator elements (114), and a second photodetector array (115) that are arranged in a stacked configuration along a radiation-receiving direction (116). The x-ray anti-scatter grid (111) comprises a plurality of septa (117.sub.A, B, C) that define a plurality of apertures (118) which are configured to collimate both x-ray quanta and gamma quanta received from the radiation receiving direction (116) such that received gamma quanta are collimated only by the x-ray anti-scatter grid (111). The use of the x-ray anti-scatter grid as a collimator for received gamma quanta results in a significantly lighter combined imaging detector.