A method for determining a spatial-sensitivity function of a gamma camera, the gamma camera observing a field of observation (Ω) liable to contain radiation sources, the gamma camera including a detector material; pixels, distributed over a detecting area, each pixel being configured to form a detection signal under the effect of detection of an interaction of an ionising photon in the detector material; a unit for achieving sub-pixel resolution, the unit being programmed to assign a position (x, y) to each detected interaction on the basis of detection signals formed by a plurality of pixels, the position being determined on a mesh dividing each pixel into a plurality of virtual pixels. The method includes steps allowing weights assigned to each virtual pixel to be determined, each weight corresponding to a sensitivity of each virtual pixel.

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).

The present disclosure provides an imaging system and method for nuclear medicine imaging. The imaging system may include a detector and a collimator. The detector may be configured to detect photons. The collimator may have at least two sets of pinholes. The at least two sets of pinholes may include a first set of first pinholes and a second set of second pinholes. Each second pinhole of the second set of second pinholes may be equipped with a filter configured to filter the photons.

The present disclosure may provide a SPECT system. The SPECT system may include a collimator including a group of first pinholes and a group of second pinholes. The group of first pinholes may be configured to remain open. The group of second pinholes may be configured to alternate between an open configuration and a blocked configuration. The collimator may be configured to allow photons to traverse through at least one group of the group of first pinholes or the group of second pinholes. The SPECT system may also include a detector configured to detect at least a portion of the photons that have traversed the collimator.

For positron emission tomography (PET) detector gain stabilization despite temperature variation, an open loop gain control based on temperature establishes a baseline gain despite possible temperature variation. The baseline gain is then adjusted with a more sensitive closed-loop (e.g., peak tracking) approach for dealing with temperature. By combining both types of gain control to deal with temperature, the advantages of both are provided while avoiding disadvantages of either approach by itself.

A two-dimensional imaging system and a two-dimensional or three-dimensional optical tomographic mapping system, each employing gas scintillation induced by ionizing radiation, i.e., radioluminescence, and corresponding methods, are disclosed. The systems may employ one or more cameras and corresponding UV filters (potentially solar blind filters) for imaging a radioluminescent scene. For two-dimensional or three-dimensional mapping, the resultant UV images are spatially registered with one another and then reconstructed to form a three-dimensional tomographic map of the ionizing radiation. The two-dimensional map is a plane of the three-dimensional map. The UV images may be spatially registered by using a reference source, optionally, a calibrated reference source allowing dosimetry calculations for the ionizing radiation. Molecular nitrogen is the primary candidate for the radioluminescent gas, though a controlled ambient in a chamber of nitric oxide, argon, krypton, or xenon may be employed. The reconstruction process employs an algebraic reconstruction technique or an Abel inversion.

The present invention relates to a Compton imaging apparatus and a single photon emission and positron emission tomography system comprising the Compton imaging apparatus and, more specifically, to a Compton imaging apparatus based on a single scintillator and a single photon emission and positron emission tomography system including the Compton imaging apparatus. The Compton imaging apparatus according to the present invention may reconstruct a Compton image based on the single scintillator composed of a plurality of scintillation cells. Thus, the Compton imaging apparatus of the present invention is cheaper than any other Compton imaging apparatuses and has an excellent time resolution such that the Compton imaging apparatus can be used even in a high-radiation area. Also, the single photon emission and positron emission tomography system using the Compton imaging apparatus can improve radiation detection efficiency and an image resolution, to thereby improve image quality.

A radiation detector head assembly includes a detector column. The detector column includes a detector having a first surface and a second surface opposite the first surface. The detector column also includes a first collimator disposed over the first surface of the detector configured for use during imaging scans involving radiation in a first energy range. The detector column further includes a second collimator disposed over the second surface of the detector configured for use during imaging scans involving radiation in a second energy range different from the first energy range.

The disclosure relates to a system and method for evaluating and calibrating detector in a scanner, further evaluating and calibrating time information detected by at least one time-to-digital convertor.

For calibration of internal dose in nuclear imaging, the dose model used for estimating internal dose in a patient is calibrated. One or more values of the dose model (e.g., a physics simulation, dose kernels, or a transport model) are set based on measured dose. The dose may be measured relative to specific tissues and/or isotopes, providing for tracer and tissue specific calibration. For example, dose from the tracer to be injected into the patient is estimated from emissions as well as measured by a dosimeter in a tissue mimicking tissue mimicking object. These doses are used to calibrate the dose model, which calibrated dose model is then used to determine internal dose for the patient.