The present invention provides a method of calibrating gamma-ray and photon counting detectors, including, but not limited to, monolithic crystal detectors. The method of the present invention is based on the observation that measurement of fan beam datasets allows the synthesis of collimated beam data to derive MDRFs by use of an algorithm that finds the common or intersecting data subsets of two or more orthogonal calibration datasets. This makes the calibration process very efficient while still allowing the full benefits of maximum-likelihood event-parameter estimation that incorporates the statistical nature of the light sensor measurements.

There are provided a phantom capable of reducing the time required to acquire calibration data even if a radiation field is large, a radiographic imaging device, and a method for calibrating a photon counting detector. A phantom, which is used in acquisition of calibration data for a photon counting detector that outputs an electric signal based on photon energy of incident radiation, includes a first basis material and a second basis material that are known materials. The first basis material has a smaller attenuation coefficient for the radiation than that of the second basis material. The first basis material varies in thickness in a stepwise fashion in a direction perpendicular to a radiation field of the radiation and, in each step, the step decreases in thickness with distance from a center of the radiation field in a direction of arrangement of detection elements of the photon counting detector.

An x-ray based litho-density tool for measurement of formation surrounding a borehole is provided, the tool including at least an internal length comprising a sonde section, wherein said sonde section further comprises an x-ray source; at least one radiation measuring detector; at least one source monitoring detector; a plurality of sonde-dependent electronics; and a reference detector, wherein the reference detector is used to monitor the output of the x-ray source such that the reference detector's output effects corrections to the outputs of the detectors used to measure the density of the materials surrounding the borehole in order to correct for variations in the x-ray source output. Tool logic electronics, PSUs, and one or more detectors used to measure borehole standoff such that other detector responses may be compensated for tool standoff are also provided.

Shielding, through-wiring, wear-pads that improve the efficacy and tool functionality are also described and claimed.

Described here are systems and methods for optimization techniques for automatically selecting x-ray beam spectra, energy threshold, energy bin settings, and other imaging technique parameters for photon-counting detector computed tomography (“PCCT”). The techniques described here are generally based on subject or object size, material of interest, and location of the target material. Advantageously, the optimizations can be integrated with different PCCT systems to automatically select optimal imaging technique parameters before scanning a particular subject or object.

A method for calibrating defective channels of a CT device involves in a step S10, acquiring original data collected by the CT device; in a step S20, capturing to-be-recovered areas from the original data, wherein the to-be-recovered areas contain the defective channels of the CT device; in a step S30, inputting data of the to-be-recovered areas to a neural network for training so as to generate training results; and in a step S40, using the training results to repair the to-be-recovered areas. The method eliminates effects of artifacts caused by defective channels on image reconstruction.

A method for generating a response function of a scintillator to incident gamma rays of energy within a range of energies of interest, the method including: obtaining the responses {S.sub.i} of the scintillator to a plurality of known radionuclides i (i=1, . . . N), each radionuclide i emitting gamma rays with known energetic properties (E.sub.ij, Y.sub.ij), decomposing, for each radionuclide i, response S.sub.i into primary responses of the scintillator S.sub.ij=ƒ(λ.sub.ij, Y.sub.ij, X.sub.ij), each primary response corresponding to the response of the scintillator to a received gamma ray of a known energy E.sub.ij for this radionuclide i, deriving from the primary responses {S.sub.ij} the response function ƒ(λ, X) of the scintillator to an incident gamma ray of any energy E within the range of energies of interest.

A method for validating the axis linearity of a displacement mechanism for a radiation detector configured to detect high-energy radiation emitted by an irradiation device comprises providing a container configured to receive a liquid. A tactile sensor and a standard element are positioned within the container configured for receiving the liquid. A displacement mechanism is structured to displace at least one of: (1) the tactile sensor; and (2) the standard element along at least one spatial axis. The tactile sensor is used to tactilely detect the standard element.

A phantom, phantom system, and method of phantom identification include a first material that forms a phantom. A phantom identifier includes at least one unit marker. The at least one unit marker identifies a physical characteristic of the phantom. In a method of phantom identification, an image of the phantom is obtained that includes the phantom identifier. The at least one unit marker is identified, the at least one unit marker encodes a value representative of a physical characteristic of the phantom.

A method and system for providing improved timing calibration information for use with apparatuses performing Time of Flight Positron Emission Tomography scans. Relative timing offset, including timing walk, within a set of processing units in the scanner are obtained and corrected using a stationary limited extent positron-emitting source, and timing offset between the set of processing units is calibrated using an internal radiation source, for performing calibration.

A dosimeter assembly being placed within an inner volume of a test article for evaluating an image produced by an x-ray computed tomography (CT) system. The dosimeter assembly includes: a dosimeter having a display, a dosimeter shelf that supports the dosimeter; and an alignment bracket that positions the dosimeter on the dosimeter shelf. The dosimeter shelf is operable to be mounted within the x-ray computed tomography system test article, and the display of the dosimeter is viewable through a dosimeter window which is disposed at a front end of the x-ray computed tomography system test article, wherein the dosimeter assembly is accessible through an access panel directly beneath the dosimeter assembly, the access panel being an opening which is disposed on a base of the x-ray computer tomography system test article. The dosimeter is operably connected to a connection interface which is configured to exchange communication with an external device.