A photon counting circuit, a radiographic imaging apparatus, and a threshold setting method are provided, in which the photon counting circuit is capable of sufficiently reducing a difference between a target threshold value and a threshold value set for a pixel even if each pixel of a photon counting detector is divided into a plurality of subpixels. In the photon counting circuit for counting, for each pixel, electrical charges generated depending on photon energy of radiation applied to an object, a pixel is divided into a plurality of subpixels. When N is a natural number, a threshold value of each of the subpixels is selected from among top N discrete values of a plurality of discrete values arranged in order of proximity to a target threshold value corresponding to the photon energy so as to minimize a difference between the target threshold value and an average of the threshold values of the respective subpixels included in the pixel.

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.

An instrument and software methodology to detect a radioactive source and incorporates the following: 1) two radiation detectors in a co-axial configuration, housed in a handheld probe, and 2) a gamma detection control unit executing software algorithms to limit the functional field of view to the front aspect of the probe, vary the depth and width of the field of view to provide collimation without the use of metallic shielding, and allowing the instrument to measure the distance to the radiation source.

A nuclear medicine diagnosis apparatus according to an embodiment includes a scintillator configured to emit self-radiation, storage, and processing circuitry. The storage stores first detection efficiency correction data that is generated based on an external radiation source or a simulation and first detection efficiency data per scintillator that is calculated based on radiation that is emitted from the scintillator. The processing circuitry calculates second detection efficiency data per scintillator that is calculated based on radiation that is emitted from the scintillator and generates second detection efficiency correction data based on the first detection efficiency correction data, the first detection efficiency data, and the second detection efficiency data.

Gamma cameras may be used to obtain two-dimensional images of an emitting object, of which the most common form is the “Anger-type” gamma camera. The primary components in a conventional Anger-type gamma camera include, but are not limited to: a plurality of photo-multiplier tubes, a scintillator material, and a collimator. The disclosed invention claims a novel use of a gamma camera which eliminates the collimator. The new method is a method of forming an initial image from the incident radiation, which does not depend on any mechanical or other means of restricting the incident radiation to be passed on to a position-sensitive radiation detector. This method then uses mathematical deconvolution to produce an image of the object without the need for a collimator and without reliance on a pre-existing image.

The present disclosure relates to a radiation sensor. In one implementation, the sensor may include a radiation detector array having a plurality of pixels; at least two readout connectors having a plurality of contacts, each readout connector being configured for receiving a readout module; a routing circuit having conductors configured for routing electrical signals from each of the plurality of pixels to a corresponding contact of one of the readout connectors. The plurality of pixels is grouped in two or more groups of pixels, at least two pixels of a first group of pixels being separated by at least one pixel from another group of pixels. The routing circuit is configured for leading pixels of the first group of pixels to a first readout connector, and pixels from the other group of pixels to a second readout connector.

A method for scintillation event localization in a radiation particle detector comprises the steps of providing a plurality of scintillator element locations (2′) configured to emit a burst of photons responsive to a radiation particle being absorbed at the scintillator element location (2′) and detecting a burst of photons emitted by a scintillator element location (2′) with a photosensor (5), wherein the photosensor (5) comprises an array of single photon avalanche diodes configured to break down responsive to impingement of a photon. Breakdown data (30) is acquired indicative of which of the single photon avalanche diodes are in breakdown and predetermined photosensor sensitivity data (20, 40) is provided, which assign single photon avalanche diodes to groups, wherein each group is assigned to exactly one scintillator element location (2′). Finally the number of single photon avalanche diodes in breakdown is determined for each group individually to identify the scintillator element location (2′) that emitted the burst of photons.

A PET apparatus and a timing correction method of this invention select two target gamma-ray detectors which count coincidences, select a reference detector which is one detector out of the two selected gamma-ray detectors, select a gamma-ray detector different from the other, opposite detector, and when repeating the selection, make a time lag histogram concerning two gamma-ray detectors selected in the past a reference, and correct a time lag histogram concerning gamma-ray detectors selected this time based on the reference. By repeating an operation to make the corrected time lag histogram concerning the two gamma-ray detectors a new reference, an optimal time lag histogram can be obtained without repeating many measurements and computations.

A position-signal processing method for flat panel gamma imaging probe includes a modeling phase and a use phase. In the modeling phase, a weight direction for an imaging detector is defined, position centers and weight ratios of the imaging detector in the weight direction are utilized to obtain a distribution graph of the weight ratios to the position centers, and curve fitting is performed upon the distribution graph to obtain a position estimation curve. In the use phase, the position estimation curve is utilized to derive a position estimation value of a probe trigger event in a 2D crystal diagram, a position value of the probe in the 2D crystal diagram with respect to the position estimation value of the probe trigger event is obtained, and a crystal code is located in a crystal code look-up table for the position value of the probe in the 2D crystal diagram.

Among other things, one or more techniques and/or systems are described for presenting images derived from a photon counting imaging modality. Initially, a first image is derived by binning native projection data in a first manner to create first binned data and generating the first image using the first binned data. A region-of-interest within the object may be identified from the first image, and, based upon the identified region-of-interest, the native projection data may be rebinned in a second, different, manner to create second binned data. Because the second manner of binning the native projection data is different than the first manner, an image resulting from the second binned data may be different than the first image. Moreover, a user interface may be provided for assisting a user in selecting a region-of-interest and/or for specifying desired properties of the second image.