Abstract: Imaging methods, imaging apparatuses and image processing devices are provided. In one aspect, an imaging method includes: scanning a subject to obtain a photon-counting sequence output by a photon-counting detector of a photon-counting CT system; determining, by using a photon-counting model and the photon-counting sequence, a target material distribution parameter value of the subject, and performing imaging based on the target material distribution parameter value. The photon-counting model is created by at least one of a charge sharing model, an energy resolution model, or a pulse pileup model. The charge sharing model is configured to eliminate energy spectrum distortion and counting loss caused by charge sharing. The energy resolution model is configured to eliminate energy spectrum distortion and counting loss caused by energy resolution. The pulse pileup model is configured to eliminate energy spectrum distortion and counting loss caused by pulse pileup.

Abstract: Methods, devices, systems, and apparatus for controlling pulse pileup are provided. In one aspect, a method of controlling pulse pileup includes: obtaining scan protocol parameters of a computed tomography (CT) device, the scan protocol parameters including an exposure voltage, an exposure duration for each revolution of a scanning of an object, and a number of views for each revolution, determining an angle of a radioactive source for an i-th view based on the number of views and an initial position of the radioactive source, obtaining an optimal exposure current for the i-th view under the exposure voltage by minimizing an output value of an objective function for the i-th view, and determining a current view based on the exposure duration for each revolution and a current exposure moment to perform the scanning on the object with the optimal exposure current for the current view.

Abstract: Imaging methods, imaging apparatuses and image processing devices are provided. In one aspect, an imaging method includes: scanning a subject to obtain a photon-counting sequence output by a photon-counting detector of a photon-counting CT system; determining, by using a photon-counting model and the photon-counting sequence, a target material distribution parameter value of the subject, and performing imaging based on the target material distribution parameter value. The photon-counting model is created by at least one of a charge sharing model, an energy resolution model, or a pulse pileup model. The charge sharing model is configured to eliminate energy spectrum distortion and counting loss caused by charge sharing. The energy resolution model is configured to eliminate energy spectrum distortion and counting loss caused by energy resolution. The pulse pileup model is configured to eliminate energy spectrum distortion and counting loss caused by pulse pileup.

Abstract: Methods, devices, systems and apparatus for arranging detector sub-modules in a medical device are provided. In one aspect, a detector includes a housing and a plurality of detector modules arranged in parallel along a direction on the housing and configured to detect rays emitted from a radiation source and attenuated by a subject. Each of the plurality of detector modules includes a support extending in the direction and a plurality of detector sub-modules arranged on the support along the direction. A top surface of each of the plurality of detector sub-modules is tangent to a respective spherical surface of a corresponding target sphere of at least two target spheres having different radiuses, and a respective sphere center of each of the at least two target spheres is substantially overlapped with a focal spot of the radiation source.

Abstract: Methods, devices, systems and apparatus for arranging detector sub-modules in a medical device are provided. In one aspect, a detector includes a housing and a plurality of detector modules arranged in parallel along a direction on the housing and configured to detect rays emitted from a radiation source and attenuated by a subject. Each of the plurality of detector modules includes a support extending in the direction and a plurality of detector sub-modules arranged on the support along the direction. A top surface of each of the plurality of detector sub-modules is tangent to a respective spherical surface of a corresponding target sphere of at least two target spheres having different radiuses, and a respective sphere center of each of the at least two target spheres is substantially overlapped with a focal spot of the radiation source.

Abstract: Methods, devices, systems, and apparatus for controlling pulse pileup are provided. In one aspect, a method of controlling pulse pileup includes: obtaining scan protocol parameters of a computed tomography (CT) device, the scan protocol parameters including an exposure voltage, an exposure duration for each revolution of a scanning of an object, and a number of views for each revolution, determining an angle of a radioactive source for an i-th view based on the number of views and an initial position of the radioactive source, obtaining an optimal exposure current for the i-th view under the exposure voltage by minimizing an output value of an objective function for the i-th view, and determining a current view based on the exposure duration for each revolution and a current exposure moment to perform the scanning on the object with the optimal exposure current for the current view.

Abstract: A method and a device for processing metal artifacts in a CT image are provided. In an example, the method includes: a first image is obtained before a metal probe is intervened; second raw data and a second image corresponding to the second raw data are obtained after the metal probe is intervened; a third image of a metal region in the second image is obtained; channels corresponding to the metal region are determined; CT values of the metal region in the second image are set to a preset value to obtain a model image and model raw data corresponding to the model image; data at the channels in the second raw data is replaced with data at the channels in the model raw data to obtain a replaced second raw data; and based on the replaced second raw data and the third image, a target image is obtained.

Abstract: Methods, devices and a machine-readable storage medium for denoising a Computed Tomography (CT) image are provided. In one aspect, a method of denoising a CT image includes: generating an original CT image according to raw data which is obtained by scanning a subject, where a pixel count of the original CT image is greater than a preset target pixel count; obtaining a denoised image by denoising the original CT image; and obtaining a target image as a CT image of the subject by compressing the denoised image to the preset target pixel count based on an interpolation algorithm.

Abstract: A filter set of a CT scanning device and control method thereof are provided. An example of the CT scanning device includes a gantry, an X-ray generator, a filter set, a detector, and a drive motor. The filter set includes a disc, a filter disposed on the disc and having a substantially annular groove structure, and a drive shaft connected to the disc. A body thickness of the annular groove structure varies in a circumferential direction and a radial direction. A shaft axis of the drive shaft is parallel to a radiation direction of X-ray. As the drive shaft is driven by the drive motor, the disc rotates around the shaft axis, such that a region of the filter is aligned with the radiation direction of the X-ray, and a body thickness of the region corresponds to a respective X-ray attenuation for an examination region of a subject.

Abstract: Provided is a method of selecting a slice configuration of a medical imaging apparatus. According to an example, an expected scanning time for scanning a region of a scanning length by the medical imaging apparatus with each of candidate slice configurations may be determined, and one or more first slice configurations are selected from the candidate slice configurations in a way that the scanning time of each of the first slice configurations is less than a preset threshold. An expected scanning length and an expected redundant scanning dose for scanning the region by the medical imaging apparatus with each of the first slice configurations may be determined. In this way, for scanning the region by the medical imaging apparatus, a target slice configuration may be selected from the first slice configurations according to the expected redundant scanning dose.

Abstract: Methods, devices and apparatus for reconstructing an image are provided. In one aspect, a method includes: determining an initial angle and a final angle of an X-ray tube and a pitch value when a helical-half-scan is to be performed, obtaining scanning data of each of reconstructing points in a reconstructing position by performing the helical-half-scan on a detected region of a subject based on the determined initial angle, the final angle and the pitch value, determining a respective half-scan-weight and a respective helical weight of each of the reconstructing points in the reconstructing position, obtaining weighted data by performing weighting on the scanning data of each of the reconstructing points with respective the half-scan-weight and the respective helical weight of the reconstructing point, and reconstructing a Computed Tomography (CT) image of the reconstructing position by performing back-projection on the weighted data.

Abstract: A method of selecting a slice configuration of a medical imaging apparatus is provided. The method includes: picking out two or more candidate slice configurations from available slice configurations of the medical imaging apparatus; determining a scan dose corresponding to each of the two or more candidate slice configurations; and selecting a candidate slice configuration corresponding to a minimum scan dose as a target slice configuration, where the target slice configuration is used for a current scan protocol.

Abstract: The present disclosure provides a sampling method and sampling apparatus of a scanning device. In at least one example, the sampling method comprises acquiring a ray attenuation variation at each of a plurality of scanning angles of the scanning device, determining a corrected sampling interval at each of the scanning angles of the scanning device by adjusting an initial sampling interval at each of the scanning angles of the scanning device according to the ray attenuation variation at each of scanning angles, and performing actual sampling according to the corrected sampling interval at each of the scanning angles of the scanning device.

Abstract: Methods and devices for reconstructing dual-energy CT images are provided. In one aspect, CT scan is performed with a high energy and a low energy periodically and alternatively changed on a scanning target, reconstruction data for a high-energy image of a current reconstruction position is obtained based on whether a circle of high-energy scan closest to the current reconstruction position of the scanning target is a full circle of scan, the high-energy image of the current reconstruction position is reconstructed according to the reconstruction data of the high-energy image; reconstruction data for a low-energy image of the current reconstruction position is obtained based on whether a circle of high-energy scan closest to the current reconstruction position of the scanning target is the full circle of scan, the low-energy image of the current reconstruction position is reconstructed according to the reconstruction data of the low-energy image.

Abstract: Methods, devices, systems and apparatus for arranging detector sub-modules in a medical device are provided. In one aspect, a detector includes a housing and a plurality of detector modules arranged in parallel along a direction on the housing and configured to detect rays emitted from a radiation source and attenuated by a subject. Each of the plurality of detector modules includes a support extending in the direction and a plurality of detector sub-modules arranged on the support along the direction. A top surface of each of the plurality of detector sub-modules is tangent to a respective spherical surface of a corresponding target sphere of at least two target spheres having different radiuses, and a respective sphere center of each of the at least two target spheres is substantially overlapped with a focal spot of the radiation source.

Abstract: The disclosure includes: judging whether a center line of an object to be scanned is deviated from a rotation axis of a gantry of a CT scanning device; determining a first distance by which the center line of the object to be scanned is deviated from the rotation axis in a case that the center line of the object to be scanned is deviated from the rotation axis; determining according to the first distance a second distance by which the shape filter is to be translated in each projection angle; and controlling the shape filter to make it translate by the second distance in each corresponding projection angle.

Abstract: A method for optimizing CT scanning parameter is disclosed. A target group may be generated from a plurality of reference information samples. Each of the reference information samples may include subject information, information indicating a scanning protocol, one or more scanning parameter values and information indicating reconstructed image quality; the target group can consist of one or more reference information samples with the same subject information and the same scanning protocol. A scanning parameter optimization may be performed according to reconstructed image qualities and scanning parameter values of reference information samples in the target group, so as to acquire a target scanning parameter value of the target group. And according to the target scanning parameter value, a reference X-ray irradiation dose corresponding to the scanning protocol and the subject information of the target group may be determined.

Abstract: Methods of reconstructing a CT image and CT devices are provided in examples of the present disclosure. In one aspect, scanning parameters for a CT device is obtained to perform a scan on a subject, a target reference detector is determined from the reference detectors according to the scanning parameters; the scan is performed on the subject according to the scanning parameters to obtain detection data outputted by the detector and reference detection data outputted by the target reference detector; energy data of the original X-rays emitted by the bulb tube with the scanning parameters is determined according to the reference detection data outputted by the target reference detector; the detection data outputted by the detector is corrected based on the energy data of the original X-rays to obtain scanning data; and the CT image of the subject is reconstructed by performing image reconstruction based on the scanning data.

Abstract: A method and a device for providing reference information for a scan protocol are provided. The method includes: obtaining first basic information and a first pilot image of a patient to be scanned as index information; retrieving a second pilot image that matches the index information from a preset scan protocol database; and outputting a second pilot image, and a second reconstructed image and a second scan protocol in the preset scan protocol database which correspond to the second pilot image as reference information. If the second pilot image matches the index information, the physical condition of a scanned patient corresponding to the second pilot image is similar to that of the patient to be scanned, and the second pilot image, and the second reconstructed image and the second scan protocol in the preset scan protocol database which correspond to the second pilot image are outputted as reference information.

Abstract: A method and a device for processing metal artifacts in a CT image are provided. In an example, the method includes: a first image is obtained before a metal probe is intervened; second raw data and a second image corresponding to the second raw data are obtained after the metal probe is intervened; a third image of a metal region in the second image is obtained; channels corresponding to the metal region are determined; CT values of the metal region in the second image are set to a preset value to obtain a model image and model raw data corresponding to the model image; data at the channels in the second raw data is replaced with data at the channels in the model raw data to obtain a replaced second raw data; and based on the replaced second raw data and the third image, a target image is obtained.