Abstract: A method for correcting projection images in CT image reconstruction is provided. The method may include obtaining a plurality of projection images of a subject. Each of the plurality of projection images may correspond to one of the plurality of gantry angles. The method may further include correcting a first projection image of the plurality of projection images according to a process for generating a corrected projection image. The process may include performing, based on the first projection image and a second projection image of the plurality of projection images, a first correction on the first projection image to generate a preliminary corrected first projection image. The process may also include performing, based on at least part of the preliminary corrected first projection image, a second correction on the preliminary corrected first projection image to generate a corrected first projection image corresponding to the first gantry angle.

Abstract: One or more embodiments of the present disclosure are directed to a transmission mechanism. The transmission mechanism may include a guiding rail, and a slider movably disposed on the guiding rail, wherein the slider may be provided with a rolling part, the rolling part may roll with respect to the guiding rail, and limit the slider in a first direction and a second direction of the guiding rail, and the first direction and the second direction may both be perpendicular to a length direction of the guiding rail, and an angle between the first direction and the second direction may be greater than 0° and less than 180°.

Abstract: A method may include obtaining an image representing a region of interest (ROI) of an object. The ROI may include two or more sub-regions. The method may include determining an average value of quantitative indexes associated with elements in the image corresponding to a first region of the ROI. The method may include determining, for each of the two or more sub-regions of the ROI, a threshold based on the average value; identifying target elements in the image based on the thresholds of the two or more sub-regions. The method may include assigning a presentation value to each of at least some of the target elements based on the average value and the quantitative index of the each target element. The method may include generating a presentation of the image based on the presentation values.

Abstract: The embodiments of the present disclosure provide a state detection method and system for an imaging device. The method includes: obtaining a first background event of a crystal of a detector of the imaging device, the first background event being related to an inherent radiating particle of the crystal; correcting a crystal position look-up table based on the first background event; correcting an energy state of the imaging device; obtaining the second background event of the crystal, the second background event being related to the inherent radiating particle of the crystal; and correcting a state of time of flight of the detector based on the first background event and the second background event.

Abstract: A radiation system is provided. The radiation system may include a bore accommodating an object, a rotary ring, a first radiation source and a second radiation source mounted on the rotary ring and a processor. The first radiation source may be configured to emit a first cone beam toward a first region of the object. The second radiation source may be configured to emit a second beam toward a second region of the object, the second region including at least a part of the first region. The processor may be configured to obtain a treatment plan of the object, the treatment plan including parameters associated with radiation segments. The processor may be further configured to control an emission of the first cone beam and/or the second beam based on the parameters associated with the radiation segments to perform a treatment and a 3-D imaging simultaneously.

Abstract: Some embodiments of the present disclosure may relate to an image processing system and method. The image processing system and method may include: obtaining an initial image; determining, based on the initial image, a plurality of to-be-processed images related to the initial image; and processing the plurality of to-be-processed images based on a processing model to obtain a target image of the initial image.

Abstract: The disclosure provides systems and methods for adjusting a multi-leaf collimator (MLC). The MLC includes a plurality of cross-layer leaf pairs, each cross-layer leaf pair of the plurality of cross-layer leaf pairs includes a first leaf located in a first layer of leaves and a second leaf opposingly located in a second layer of leaves. For at least one cross-layer leaf pair, an effective cross-layer leaf gap to be formed between the first leaf and the second leaf may be determined; at least one of the first leaf or the second leaf may be caused to move to form the effective cross-layer leaf gap; and an in-layer leaf gap may be caused, based on the effective cross-layer leaf gap, to be formed between the first leaf and an opposing first leaf in the first layer. A size of the in-layer leaf gap may be no less than a threshold.

Abstract: A scanning apparatus (110), a medical image obtaining method, and a medical image obtaining system (100) are provided. The scanning apparatus (110) comprises a gantry, a controller, a C-shaped arm, a radiation source (112), and a detector (113). The radiation source (112) and the detector (113) are arranged at both ends of the C-shaped arm. The C-shaped arm is connected to the gantry. The controller is configured to control a motion of the gantry to drive the C-shaped arm to move so as to scan a target object.

Abstract: The present disclosure provides a system for patient monitoring. The system may cause a medical device to perform a treatment or a scan on a patient who remains in a breath-hold status. During the treatment or the scan of the patient, the system may acquire one or more parameter values relating to one or more status parameters that reflect the breath-hold status of the patient using a monitoring device. The system may also predict a breaking point of the breath-hold status based on the one or more parameter value. The system may further adjust the treatment or the scan based on the breaking point of the breath-hold status.

Abstract: Systems and methods for determining an offset of a position of a focal point of an X-ray tube is provided. The methods may include obtaining at least one parameter associated with an X-ray tube during a scan of a subject. The methods may further include determining a target offset of a position of a focal point based on the at least one parameter and a target relationship between a plurality of reference parameters associated with the X-ray tube and a plurality of reference offsets of reference positions of the focal point. The methods may further include causing, based on the target offset, a correction on the position of the focal point of the X-ray tube.

Abstract: A method may include obtaining first image data relating to a region of interest (ROI) of a first subject. The first image data corresponding to a first equivalent dose level may be acquired by a first device. The method may also include obtaining a model for denoising relating to the first image data and determining second image data corresponding to an equivalent dose level higher than the first equivalent dose level based on the first image data and the model for denoising. In some embodiments, the method may further include determining information relating to the ROI of the first subject based on the second image data and ecording the information relating to the ROI of the first subject.

Abstract: The present disclosure relates to systems and methods for image storage. The methods may include obtaining a first image of a subject. The methods may further include obtaining a second image of the subject. The second image may include scan status information of the subject. The scan status information may be associated with a status of the subject when the first image is acquired. And The methods may also include storing the second image correspondingly with the first image.

Abstract: A method for driving a leaf of a multi-leaf collimator (MLC) is provided. The method may include obtaining a target position of the leaf; identifying a current position of the leaf; generating a first control signal based on the target position of the leaf and the current position of the leaf; generating a second control signal based on at least one of a target velocity of the leaf, a target acceleration of the leaf, or a current angle of the leaf; generating a third control signal based on the first control signal and the second control signal; and/or causing a drive circuit to generate a driving signal for driving the leaf to move towards the target position by providing the third control signal to the drive circuit.

Abstract: The present disclosure may provide a system. The system may obtain a first image of a first region of a subject and a second image of a second region of the subject. The first region and the second region may have an overlapping region. The system may generate a first corrected image by correcting the first image based on the second image and a second corrected image by correcting the second image based on the first image. The system may generate a combined image by combining the first corrected image and the second corrected image.

Abstract: Systems and methods for determining one or more target examination parameters is provided. The methods may include obtaining target examination information of a subject and generating one or more initial examination parameters based on the target examination information. The methods may further include obtaining one or more historical examination parameters associated with the subject and updating at least one of the one or more initial examination parameters based on the one or more historical examination parameters to obtain one or more target examination parameters. The one or more target examination parameters may be used for performing a target examination on the subject.

Abstract: The present disclosure is related to systems and methods for image evaluation. The method may include obtaining an original image including a representation of at least one subject. The method may include generating a plurality of target positioning results for each of the at least one subject by inputting the original image into a prediction model. The prediction model may include a plurality of branches. Each of the plurality of target positioning results may correspond to a branch of the plurality of branches. The method may include determining an evaluation result corresponding to the original image based on the plurality of target positioning results.

Abstract: The present disclosure may provide a magnetic resonance (MR) system. The MR system may include a magnet assembly, a gradient coil assembly, and a shim assembly. The magnet assembly may be configured to generate a main magnetic field. The magnet assembly may include a magnet and a cryostat configured to cool the magnet located inside the cryostat. The cryostat may form a bore. The gradient coil assembly may be configured to generate a gradient magnetic field. The gradient coil assembly may be located inside the bore. The shim assembly may be configured to at least partially shield a stray field which is generated by the gradient coil assembly and to which the magnet is subjected. The shim assembly may be located outside the gradient coil assembly.

Abstract: The present disclosure relates to systems and methods for image reconstruction. The systems and methods may obtain an initial image to be processed. The systems and methods may also generate a reconstructed image by performing a plurality of iteration steps on the initial image. At least one of the plurality of iteration steps may include a first optimization operation and a second optimization operation. The first optimization operation may include receiving an image to be processed in the iteration step and determining an updated image by preliminarily optimizing the image to be processed. The second optimization operation may include determining, using an optimizing model, an optimized image based on the updated image and designating the optimized image as a next image to be processed in a next iteration step or designating the optimized image as the reconstructed image.

Abstract: The present disclosure relates a multi-leaf collimator. The multi-leaf collimator may include a plurality of leaves. At least two leaves of the plurality of leaves may be movable parallel to each another. For each leaf of at least some of the plurality of leaves, at least one portion of the leaf may have thicknesses varying along a longitudinal direction of the each leaf. The each leaf may have a first end and a second end along the longitudinal direction of the each leaf.

Abstract: The present disclosure relates to a cavity of a medical device. The cavity may include a bore and an accommodating cavity configured to provide an accommodating space for at least a portion of a couch in a radial direction of the bore. The accommodating cavity may be disposed on an inner wall of the bore and extend along an axial direction of the bore, and the accommodating cavity may be configured to form, with the bore, a connected space in which the at least a portion of the couch is allowed to move along an axial direction of the bore.