Abstract: A method for delivering radiation treatment may include defining a preliminary trajectory including a plurality of control points. Each control point may be associated with position parameters of a gantry and a couch. The method may also include generating a treatment plan based on the preliminary trajectory by optimizing an intensity and position parameters of a collimator and MLC leaves for each control point. The method may also include decomposing the treatment plan into a delivery trajectory including the plurality of control points. Each of the plurality of control points may be further associated with the optimized intensity, the optimized position parameters of the collimator and the MLC leaves, an output rate, and a motion parameter of each of the gantry, the couch, the collimator, and the MLC leaves. The method may further include instructing a radiation delivery device to deliver the treatment plan according to the delivery trajectory.

Abstract: A multi-leaf collimator is provided. The multi-leaf collimator may include a plurality of leaves configured to shield radiation beams. At least two leaves of the plurality of leaves may be movable in a direction parallel to each another. Each leaf of at least some of the plurality of leaves may be configured to be movable between at least two positions. At least one of the at least two positions may be adjustable.

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: A radiation system may include a treatment assembly including a first radiation source, a second radiation source, and a first radiation detector. The first radiation source may be configured to deliver a treatment beam covering a treatment region of the radiation system, and the treatment region may be located in a bore of the radiation system. The second radiation source may be configured to deliver a first imaging beam covering a first imaging region of the radiation system, and may be mounted rotatably on a first side of the treatment assembly. The first radiation detector may be configured to detect at least a portion of the first imaging beam, and may be mounted rotatably on a second side of the treatment assembly. The treatment assembly, the second radiation source, and the first radiation detector may be positioned such that the treatment region is addressable for the radiation system.

Abstract: A multi-leaf collimator is provided. The multi-leaf collimator may include a plurality of leaves configured to shield radiation beams. At least two leaves of the plurality of leaves may be movable in a direction parallel to each another. Each leaf of at least some of the plurality of leaves may be configured to be movable between at least two positions. At least one of the at least two positions may be adjustable.

Abstract: A radiation treatment system may include a gantry configured to rotate around an object, a treatment head moving with the gantry, a plurality of imaging radiation sources configured to emit imaging beams toward the object, and one or more first detectors configured to detect at least a portion of the imaging beams. When the treatment head is delivering a treatment beam to the object, the plurality of imaging radiation sources and the one or more first detectors may be positioned outside at least a portion of a maximum treatment radiation region so as not to interfere with the treatment beam. At least one of the plurality of imaging radiation sources and the one or more first detectors may be positioned at or near an edge of the maximum treatment radiation region.

Abstract: A system, medium, and method including obtaining a plurality of positions for multiple components defined by a plan; obtaining a set of constraints that express limitations for the multiple components at the plurality of positions, the constraints being applicable to a plan where the multiple components synchronously change their positions with time to traverse a prescribed sequence of the plurality of positions, at least one of the multiple components being further constrained to change its position over time by staying within a predefined tolerance to a predefined smooth function of position over time between different positions; determining a trajectory of position and a minimum duration in which the multiple components completely synchronously traverse the prescribed sequence of positions while satisfying the constraints for the multiple components; and generating a record of the determined trajectory of position and the minimum duration for the plurality of components.

Abstract: A system and method for adapting treatment plan are provided. The method may include: obtaining a planning image of a region of interest relating to a first treatment fraction of a first treatment plan; obtaining a first image of the region of interest relating to a first scan of the region of interest with a first dose level; comparing the planning image with the first image to generate a first comparison result; determining whether the first comparison result satisfies a first replanning condition; causing, in response to a determination that the first comparison result satisfies the first replanning condition, one or more scanners to perform a second scan with a second dose level to provide a second image; and generating a second treatment plan according to the second image, wherein the second dose level is higher than the first dose level.

Abstract: A target assembly for generating radiation may comprise a target, a substrate and a window. The target may be capable of generating first radiation when impinged by a beam. The window may be at least partially permeable to the beam. The window and the substrate may form at least part of a hermetically sealed chamber and the target may be positioned in the chamber. The chamber may be filled with air having a normal or reduced content of oxygen.

Abstract: The present disclosure is related to systems and methods for isocenter calibration. The method includes providing a phantom including a first member and a second member with a fixed position relationship. The method includes acquiring, using a first device, at least one first image of the first member of the phantom. The method includes determining, based on the at least one first image, a first position relationship between a first isocenter of the first device and the first member. The method includes acquiring, using a second device, at least one second image of the second member of the phantom. The method includes determining, based on the at least one second image and the fixed position relationship, a second position relationship between a second isocenter of the second device and the first member. The method includes determining, based on the first position relationship and the second position relationship, a third position relationship between the first isocenter and the second isocenter.

Abstract: A system for limited view imaging is provided. The system may obtain a reference image of an object. The system may identify, from the reference image, one or more critical boundaries between a target organ of the object and one or more adjacent organs of the target organ. The system may determine an imaging angle range of the object based on the one or more critical boundaries. The system may further cause an imaging device to scan the object based on the imaging angle range, the object being in a breath-hold state during the scan.

Abstract: The present disclosure provides a system and method for medical imaging. The method may include obtaining a treatment plan, a planning image, and one or more treatment images of the subject, wherein the one or more treatment images are generated by performing at least a portion of the treatment plan including delivering at least a radiation beam towards the subject using a radiation device. The method also includes determining primary images of the subject based on the one or more treatment images, and determining inversely-attenuated primary images of the subject by inversely attenuating the primary images to a plane located between the subject and a collimator assembly of the radiation device. The method may further include estimating machine parameters of the radiation device corresponding to the inversely-attenuated primary images.

Abstract: A system and method for generating augmented segmented image set obtain are provided. The method may include: obtaining a first image including a first anatomical structure of a first object; determining first feature data of the first anatomical structure; determining one or more first transformations related to the first anatomical structure, wherein a first transformation includes a transformation type and one or more transformation parameters related to the transformation type; applying the one or more first transformations to the first feature data of the first anatomical structure to generate second feature data of the first anatomical structure; and generating a second image based on the second feature data of the first anatomical structure.

Abstract: A radiation treatment device may include a first dosimeter and a second dosimeter. Quantum efficiency of the first dosimeter may be lower than quantum efficiency of the second dosimeter. A method for monitoring beam energy may include receiving a first signal generated by a first dosimeter, receiving a second signal generated by a second dosimeter, receiving a third signal generated by the first dosimeter and receiving a fourth signal generated by the second dosimeter. The first signal and the second signal may be associated with a first radiation beam. The second signal and the fourth signal may be associated with a second radiation beam. The method may also include determining whether there is a difference between the beam energy of the first radiation beam and the second radiation beam based on at least one of the first signal, the second signal, the third signal or the fourth signal.

Abstract: The present disclosure relates to systems and methods for pulse parameter modulation. The systems may perform the methods to obtain information related to a treatment plan; determine a backward window based on the information related to the treatment plan, within which one or more radiation pulses have been transmitted; determine backward information associated with the backward window based on the information related to the treatment plan and the backward window; determine a forward window based on the information related to the treatment plan, within which one or more radiation pulses are to be transmitted; determine forward information associated with the forward window based on the information related to the treatment plan, the backward information, and the forward window; and determine one or more pulse parameters of the forward window based on the forward information.

Abstract: A system, medium, and method including obtaining a plurality of positions for multiple components defined by a plan; obtaining a set of constraints that express limitations for the multiple components at the plurality of positions, the constraints being applicable to a plan where the multiple components synchronously change their positions with time to traverse a prescribed sequence of the plurality of positions, at least one of the multiple components being further constrained to change its position over time by staying within a predefined tolerance to a predefined smooth function of position over time between different positions; determining a trajectory of position and a minimum duration in which the multiple components completely synchronously traverse the prescribed sequence of positions while satisfying the constraints for the multiple components; and generating a record of the determined trajectory of position and the minimum duration for the plurality of components.

Abstract: A method and system for using in a two-modality apparatus. The two-modality apparatus comprises a couch with a table top, a first modality unit and a second modality unit. A second image of a target portion of an object when the table top is at a second working position of the second modality unit may be acquired. A second sag of the table top at a second measurement point of the table top according to the second image may be determined based on the image. A difference between a first sag of the table top at a first measurement point of the table top and the second sag may be estimated based on the second sag and standard data. The standard data provides a relationship relating to a sag of the table top positioned between the first modality unit and second modality unit.

Abstract: A system and method for generating augmented segmented image set obtain are provided. The method may include: obtaining a first image including a first anatomical structure of a first object; determining first feature data of the first anatomical structure; determining one or more first transformations related to the first anatomical structure, wherein a first transformation includes a transformation type and one or more transformation parameters related to the transformation type; applying the one or more first transformations to the first feature data of the first anatomical structure to generate second feature data of the first anatomical structure; and generating a second image based on the second feature data of the first anatomical structure.

Abstract: A multi-leaf collimator is provided. The multi-leaf collimator may include a plurality of leaves configured to shield radiation beams. At least two leaves of the plurality of leaves may be movable in a direction parallel to each another. Each leaf of at least some of the plurality of leaves may be configured to be movable between at least two positions. At least one of the at least two positions may be adjustable.

Abstract: A radiation treatment device may include a first dosimeter and a second dosimeter. Quantum efficiency of the first dosimeter may be lower than quantum efficiency of the second dosimeter. A method for monitoring beam energy may include receiving a first signal generated by a first dosimeter, receiving a second signal generated by a second dosimeter, receiving a third signal generated by the first dosimeter and receiving a fourth signal generated by the second dosimeter. The first signal and the second signal may be associated with a first radiation beam. The second signal and the fourth signal may be associated with a second radiation beam. The method may also include determining whether there is a difference between the beam energy of the first radiation beam and the second radiation beam based on at least one of the first signal, the second signal, the third signal or the fourth signal.