Aspects of the invention relate to generating an emission activity image as well as an emission attenuation map using an iterative updation based on both the raw emission projection data and the raw radiography projection data, and an optimization function. The outputs include an optimized emission activity image, and at least one of an optimized emission attenuation map or an optimized radiography image. In some aspects an attenuated corrected emission activity image is obtained using the optimized emission activity image, and the optimized emission attenuation map.

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.

For calibration (24) for quantitative SPECT, a multiple energy emission source (11) is used for calibration. The planar sensitivities and/or uniformities are determined at different emission energies based on detections from the multiple energy emission source. For estimating (32) the activity concentration, sensitivities and/or uniformities based on measures (26) at different emission energies increase accuracy. The multiple energy emission source (11) may alternatively or additionally be used to calibrate (40) a dose calibrator (15).

The invention relates to a system for detecting gamma radiation, such as a gamma camera, including a source of gamma rays, at least one plate P1 of a fast scintillator, the time thereof for rising to the light peak being less than 1 ns, said plate comprising a diffusing entry surface and a polished exit surface, having a thickness of no less than 10 mm, being provided with photodetectors and microelectronics for dedicated reading, characterized in that the microelectronics are of the ASIC type, in that the detector is segmented, and in that on said plate P1, each segment of said detector is capable of measuring a first trigger T1 such that a time resolution is lower than 100 ps; the detector can measure a space and time distribution of the first adjacent photons emitted by an event on the detectors for a time of more than 100 ps and no longer than the time for rising to the light peak of the scintillator. The invention further relates to the image-reconstruction method implemented in the system, as well as to the implementation and use of said system. The invention additionally relates to the image-reconstruction method and to the method for improving the energy resolution of the detector installed in the system, as well as to the implementation of said system.

A system (10) and a method (150) identify non-functioning pixels in positron emission tomography (PET) imaging. Data describing scintillation events localized to a plurality of pixels (22, 32) of a PET scanner (12) is received. A count map histogram is generated from the received data. The count map histogram maps each of the pixels (22, 32) to a count of scintillation events localized to the pixel (22, 32). One or more non-functioning pixels are identified from the count map histogram.

Disclosed herein is a method for removing septal shadows from thick septa collimator images, comprising disposing a line radiation source in a first orientation with respect to an imaging detector; disposing a thick septa collimator between the line radiation source and the imaging detector; where the collimator and the detector move in unison with one another; obtaining a plurality of a line images, where each line image is taken at a different location of the line radiation source with respect to the thick septa collimator; wherein each different location of the line radiation source is along a first linear direction; and relocating the plurality of the line images so obtained to a common location; and summing the images to reduce the septal shadow effects.

A system includes a detector and a main processing unit having an event processing module. The detector includes pixels to detect an event corresponding to photon absorption. The event processing module is configured to read event information for each event detected by each pixel of the detector in order of receipt from the detector and to compare an energy level value in the event information for each event to a predetermined range of energy level values. An event is counted when the energy level value is within the predetermined range of energy level values. For each event having an energy level below the predetermined range, the energy level value for a next consecutive event in the received event information is read and a combined energy level value of the event and the next consecutive event is determined as well as the pixel locations of the event and the next consecutive event. The combined energy level is counted as a single event when the combined energy level value is within a predetermined range of energy level values and when the pixel location for the event is near a pixel location for the next consecutive event. At least one pixel location is assigned to the single event.

The present invention relates the system of the correction of energy crosstalk in dual-isotopes simultaneous acquisition (DISA), the system includes a collimator, a metal thin film, a detecting unit, an analyzing unit and a display unit for analyzing energy distribution charts of the dual-isotopes, and using specific equations or artificial neural network methods or independent component analysis to compare the energy distribution charts which are with and without metal thin film The invention uses the metal thin film to remove the energy contamination from dual-isotopes simultaneous acquisition whose photopeak energies are close, the invention effectively separates the energy distribution charts without energy crosstalk, therefore, the system improves diagnostic imaging and relieves patient's discomfort.

Single photon emission computed tomography (SPECT) is performed with multiple emission energies. For quantitative or qualitative SPECT, the image formation process for emissions at different energy ranges is modeled (44, 46, 48, 50) separately. Different scatter, different attenuation, and/or different collimator-detector response models corresponding to different energy ranges are used in the reconstruction.

Advantageous methods, systems, and computer-readable media are provided. An attenuation map for an image can be reconstructed with no known sub-region of the attenuation map prior to performing the method. Gradient data of an attenuation sinogram can be estimated, and an algorithm can be performed to reconstruct the attenuation map from the estimated gradient data of the attenuation sinogram.