For calibration in medical emission tomography, the dosimeter and/or detector is calibrated in the field, such as at the clinic or other patient scanning location. To allow for a fewer number of calibration sources used in calibrating and/or assist in calibration for multispectral emission tomography, a calibration source includes multiple isotopes and/or a proxy source or isotope is used instead of the same isotope used in factory calibration.

Methods and apparatus for calibrating radioactive sources are described. An array of scintillation detectors form a receptacle within which a sample or sample container can be retained by a holder. The scintillation detectors are coupled via light transducers such as photomultiplier tubes (PMTs) to independent electronic counters. Coincidence processing of time-tagged events yields a correlated event rate. One or more corrections can be applied as needed, for background counts, deadtime, or random coincidences. Voltage tuning of PMTs yields improved reproducibility. Variations are disclosed. 1% accuracy has been demonstrated over a range of 10 kBq-3 MBq, covering a gap in the capabilities of conventional technology.

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.

Systems and methods for dose calibration. A dose calibrator may include one or more radiation sources, one or more solid-state detectors and one or more plates positioned between the one or more radiation sources and the one or more solid-state detectors. The one or more solid-state detectors capture one or more images based on emissions received from the one or more radiation sources through the one or more plates for estimating activity of the one or more radiation sources.

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).

A method and apparatus for diagnosing and/or calibrating underperforming pixels in detectors in a small pixelated photon counting CT system utilizes a series of tests on image data acquired in-situ as part of a series of calibration scans in the CT system. Tests are performed on the acquired data to determine the existence of underperforming pixels within the detectors such that the information acquired by those pixels can be replaced by alternate data from surrounding pixels (e.g. by interpolation). The underperforming pixels are stored in “bad” pixel tables and may be specific to a type of image (e.g., spectral or counting) and a specific protocol.

According to one embodiment, an X-ray diagnostic apparatus includes processing circuitry. The processing circuitry is configured to execute first calculation processing of calculating three-dimensional position information of each of an X-ray generator and an X-ray detector during rotation imaging, based on projection data acquired by executing the rotation imaging for a phantom with the X-ray generator and the X-ray detector arranged rotatably around the phantom.

A Cherenkov-based or thin-sheet scintillator-based imaging system uses a radio-optical triggering unit (RTU) that detects scattered radiation in a fast-response scintillator to detect pulses of radiation to permit capture of Cherenkov-light or scintillator-light images during pulses of radiation and background images at times when pulses of radiation are not present without need for electrical interface to the accelerator that provides the pulses of radiation. The Cherenkov images are corrected by background subtraction and used for purposes including optimization of treatment, commissioning, routine quality auditing, R&D, and manufacture. The radio-optical triggering unit employs high-speed, highly sensitive radio-optical sensing to generate a digital timing signal which is synchronous with the treatment beam for use in triggering Cherenkov light or scintillator light imaging.

A wide area cosmogenic neutron sensor is used for detecting moisture within a measurement surface. A neutron detector is positioned on a stand structure holding the detector above a measurement surface. A moderator material and neutron shield are positioned around at least a portion of the neutron detector. The neutron shield substantially covers an entirety of a bottom of the neutron detector and is not positioned on a top side of the neutron detector. Wide area cosmogenic neutrons propagating from the measurement surface travel through an air space before arriving at the moderated neutron detector.

A system for evaluating the scan quality of a scanner on a test piece is provided. The system includes a processor and a memory in communication to the processor for storing instructions executable by the processor, such that the processor is configured to receive a scanned image of the test piece from the scanner, display the scanned image, generate a first score value based on the scanned image, display an evaluation input interface configured to receive user evaluation input based on the evaluation of the scanned image, and generate a second score value based on the user evaluation input, such that the first score value and the second score value are utilized to evaluate the scan quality of the scanner. Further, a method for evaluating the scan quality of the scanner is provided.