A positron emission tomography apparatus according to an embodiment includes a plurality of positron emission tomography (PET) detector entities and processing circuitry. The plurality of PET detector entities are arranged in a ring formation. The processing circuitry is configured: to obtain, with respect to each of the plurality of PET detector entities, state information indicating a state of the PET detector entity; to detect an abnormality when an index value indicating a state of any individual or a whole of the plurality of PET detector entities exceeds a threshold value on the basis of the state information; and to detect a state in which the abnormality is not detected on the basis of the state information, but an index value indicating states of at least two of the plurality of PET detector entities is different from an index value indicating states of at least two other PET detector entities.

The present invention provides a method for calibrating a working plane of a medical detection apparatus, which is used for calibrating the working plane of the medical detection apparatus to be parallel with a first reference plane, wherein the working plane has a first point to be calibrated and a second point to be calibrated thereon, the first point to be calibrated is located on the first reference plane, and the first point to be calibrated and the second point to be calibrated are respectively supporting points of a first foot and a second foot for supporting the working plane on the working plane, the above method comprising: receiving at least one first inclination angle value from an angle measuring tool, wherein each first inclination angle value is an angle between a line connecting the first point to be calibrated and the second point to be calibrated and the first reference plane; computing a vertical distance between the second point to be calibrated and the first reference plane as a first magnitude of adjustment according to a pre-stored distance between the first point to be calibrated and the second point to be calibrated and the first inclination angle value; and adjusting a height of the second foot according to the first magnitude of adjustment to allow the second point to be calibrated to be located on the first reference plane.

Systems, devices, and methods are presented for automatic tuning, calibration, and verification of radiation therapy systems comprising control elements configured to control parameters of the radiation therapy systems based on images obtained using electronic portal imaging devices (EPIDs) included in the radiation therapy system.

This X-ray phase imaging system includes a plurality of gratings including a first grating that is irradiated with X-rays from an X-ray source and a second grating that is irradiated with X-rays from the first grating. The X-ray phase imaging system includes an imaging unit that optically images a subject and one or both of the first grating and the second grating.

Methods and systems are provided for boosting the contrast levels in an image reconstructed from projection data acquired at a single energy. In one embodiment, a method comprises modifying projection data corresponding to a material based on an absorption behavior of the material at a selected energy, wherein the projection data is acquired at an energy higher than the selected energy. In this way, contrast levels may be enhanced in an image reconstructed from projection data acquired at a typical single energy as though the image were reconstructed from projection data acquired at a lower energy.

A method for correction of an input dataset is disclosed. In an embodiment, the method includes acquisition of an input dataset comprising at least one data error; determination of a correction function; creation of a corrected output dataset by application of the correction function to the input dataset; and outputting of the corrected output dataset. The correction function is embodied to bring about a reduction of at least two data errors that mutually influence one another in the input dataset.

There is provided an image processing apparatus for reconstructing a tomographic image of a subject based on a plurality of projection images obtained by detecting radiation emitted from a plurality of different positions. The image processing apparatus reconstructs a first tomographic image from the plurality of projection images, extracts a fixed pattern occurring in the first tomographic image due to a radiation detector, and forms a second tomographic image by updating the first tomographic image using a value concerning intensity of the fixed pattern as a regularization term. The image processing apparatus outputs, as the tomographic image of the subject, the second tomographic image obtained by the update.

An apparatus, system and method for calibrating an x-ray apparatus including acquiring sinogram data by scanning a symmetrical phantom using a plurality of detector channels; generating mirror-copied sinogram data by mirror-copying at least one of first sinogram data and second sinogram data of the acquired sinogram data, wherein the first sinogram data and the second sinogram data are generated by dividing the sinogram data at a center detector channel of the plurality of detector channels; outputting a first reconstructed image by reconstructing the mirror-copied sinogram data; and determining a calibration parameter based on the first reconstructed image.

The invention relates to a detection apparatus (12) for detecting photons. The detection apparatus comprises a pile-up determining unit (15) for determining whether detection signal pulses being indicative of detected photons are caused by a pile-up event or by a non-pile-up event, wherein a detection values generating unit (16) generates detection values depending on the detection signal pulses and depending on the determination whether the respective detection signal pulse is caused by a pile-up event or by a non-pile-up event. In particular, the detection values generating unit can be adapted to reject the detection signal pulses caused by pile-up events while generating the detection values. This allows for an improved quality of the generated detection values.

A method and apparatus for estimating a parameter vector including a plurality of parameters of a detector response model of a photon-counting detector. The method includes calculating a modeled spectrum based on an input spectrum and an initial value of the plurality of parameters. For each detector, a difference between the normalized photon count of the measured spectrum and the normalized modeled spectrum is calculated. A root mean square error (RMSE) between the measured and modeled spectra is obtained by squaring the normalized difference and weighting the normalized difference by a weighting factor. The parameter vector is updated until an optimum RMSE value is achieved. Upon determining optimal values of the parameter vector, measured data that is obtained via a patient scan is corrected based on the optimal parameter vector.