The present invention relates to spectral correction. A spectral correction apparatus is described that is configured to identify a voltage fluctuation in the X-ray tube and to parameterize the high voltage fluctuation to correct the effective X-ray spectrum per individual frame.

In general, an X-ray imaging apparatus according to one embodiment includes an X-ray tube, an X-ray detector, and processing circuitry. The processing circuitry is configured to obtain correction-target data that includes component deterioration resulting from a transient response of the X-ray detector, and to output, based on the obtained correction-target and a model that outputs data in which component deterioration resulting from a transient response is reduced based on an input of data that includes component deterioration resulting from a transient response, corrected data in which the component deterioration resulting from the transient response of the X-ray detector is reduced.

A medical imaging system is provided. Imaging detector columns are installed in a gantry to receive imaging information about a subject. Imaging detector columns can extend and retract radially as well as be rotated orbitally around the gantry. The system can automatically adjust setup configuration and an imaging operation based on subject shape estimation information.

A method of determining at least one x-ray scanning system geometric property includes the steps of positioning a calibration device inside a scanning chamber of the scanning device, the chamber being intersected by at least one fan beam of x-rays during a scanning operation, measuring a distance between the calibration device and at least one inner wall of the chamber, scanning the calibration device to produce an image of the calibration device, identifying pixels representing the a geometric feature of the calibration device in the image, determining a position and orientation of the pixels representing the geometric feature in the image and, determining a scanning system property based on the position and orientation of the pixels representing the geometric feature in the image. The position and orientation of the feature in the scanning chamber and the x-ray scanning system property may be determined simultaneously.

A method for estimating motion of an X-ray focal spot is provided. The acts of the method include acquiring image data by causing X-rays to be emitted from the X-ray focal spot of an X-ray source toward a radiation detector comprising multiple channels, wherein a subset of the channels each have a collimator blade positioned above the respective channel. The acts of the method also include independently estimating X-ray focal spot motion in an X-direction for the X-ray focal spot relative to an isocenter of the radiation detector and in a Y-direction along a direction of the X-rays for the X-ray focal spot relative to the isocenter based on respective channel gains for a first channel and a second channel of the subset of the channels.

A radiation imaging system comprises: an image obtaining unit including a radiation detecting unit in which pixels configured to output signals according to a dose of irradiated radiation are arranged in a two-dimensional area, and configured to obtain a radiation image based on the signals; a correction unit configured to correct the radiation image using an input/output characteristic of a pixel, which represents a relationship between the dose of radiation on the pixel and the signal output from the pixel and is obtained using gain data based on a plurality of gain images obtained under different doses; and an updating unit configured to update the gain data using an updating coefficient obtained based on the gain data and a gain image newly obtained by the image obtaining unit.

The application provides a three-dimensionally heterogeneous PET system comprising at least two heterogeneous detector modules, each comprising at least two kinds of crystal strips closely arranged to form different detection performances levels for different kinds of crystal strips and same detection performances levels for same kind of crystal strips. Parameters of detection performances of crystal strips comprise energy resolution, density, size and light output, wherein different detection performances levels for crystal strips comprise one or more of parameters of detection performances of crystal strips being in different levels. Compared with a high spatial resolution PET system, the application effectively reduces manufacturing costs of a PET system without significantly reducing spatial resolution thereof. Compared with an ordinary spatial resolution PET system, it improves spatial resolution of a PET system by slightly increasing its cost, and can also provide imaging field of view with high spatial resolution in radial direction.

Disclosed herein is a medical instrument (100, 300, 400, 500) comprising: a memory (110) storing machine executable instructions (120) and a tomographic data assessment module (122) and a processor (106) configured for controlling the medical instrument. Execution of the machine executable instructions causes the processor to receive (200) measured tomographic data (124). The measured tomographic data is configured for being reconstructed into a tomographic image (308) of a subject (418). Execution of the machine executable instructions further causes the processor to receive (202) an image quality indicator (126, 126′, 126″) by inputting the measured tomographic data into the tomographic data assessment module. The tomographic data assessment module is configured for generating the image quality indicator in response to inputting the measured tomographic data. Execution of the machine executable instructions further causes the processor to provide (204) the image quality indicator to an operator using an operator signaling system (108).

An apparatus, for dose measurement designed for use in an x-ray device, is disclosed. In an embodiment, the apparatus includes a mirror element designed to inject a light field into an x-ray beam penetrating through the mirror element; and a measuring device to measure radiation-induced changes to a carrier material. The carrier material is part of the mirror element and/or another component of the apparatus, which lies in the radiation field of the x-ray device when used normally in an x-ray device. A corresponding method for dose measurement and to an x-ray device is also disclosed.

Provided in the invention is a method and a device of Correction of a ring artifact in a CT image and a computer program medium. The method of correction comprises: pre-processing original detection data; marking a bad detector according to data in the pre-processed original sinogram; acquiring a replacing detection value corresponding to the bad detector by means of a first averaging processing; and performing a CT image reconstruction using a sinogram data after the first averaging processing. The device comprises: a pre-processing unit configured to pre-process original detection data; a marking unit configured to mark a bad detector according to data in the pre-processed original sinogram; a first averaging processing unit configured to acquire a replacing detection value corresponding to the bad detector by means of a first averaging processing; and an image reconstruction unit. The invention is able to effectively eliminate the ring artifact in the CT image, and at the same time ensure that there is little loss of the spatial resolution of the CT image.