Abstract: The present disclosure relates to systems and methods for positioning a region of interest (ROI). The systems may obtain an image of an object captured by an imaging device. The systems may extract image information of the image. The systems may obtain feature information of a region of interest (ROI) in the object. The systems may determine position information of the ROI in the image using a positioning model based on the image information of the image and the feature information of the ROI.

Abstract: The present disclosure relates to a device and methods for clock synchronization. The device may include a first synchronization component and one or more second synchronization components. The first synchronization component may be configured to transmit a first synchronization signal to the one or more second synchronization components. Each second synchronization component of the one or more second synchronization components may be configured to generate a second synchronization signal based on the first synchronization signal and transmit the second synchronization signal to one or more detectors. The second synchronization signal may be configured to reset a clock of a detector of the one or more detectors corresponding to the each second synchronization component.

Abstract: A method for attenuation map generation may include obtaining first PET data relating to first background events occur during a first PET scan, which is performed by a PET scanner with no subject within a detection tunnel of the PET scanner; obtaining second PET data relating to second background events occur during a second PET scan, which is performed by the PET scanner with a subject within the detection tunnel; generating, based on the first PET data and the second PET data, a target attenuation map of the subject, wherein the first background events and the second background events may occur when a first particle and a second particle are detected by crystal units of the PET scanner within a background coincident window, and the first particle and the second particle may be different types of particles produced by a radioactive decay of a crystal material of the PET scanner.

Abstract: The present disclosure may provide a method. The method may include obtaining a PET dataset relating to a subject acquired, based on a tracer species in the subject, by a PET device. The PET dataset relating to the subject may be acquired for a time period when the subject moves by moving a couch on which the subject is supported. The time period may include a first time segment and a second time segment. The method may also include determining an activity distribution set of the tracer species in the subject within the time period. The activity distribution set may include a plurality of segment activity distributions. Further, the method may include determining an offset of the couch within the second time segment with respect to the first time segment based on the activity distribution set of the tracer species.

Abstract: A system for radiation therapy may obtain a plurality of sets of motion data each of which corresponds to one of a plurality of motion phases of a subject. A set of motion data corresponding to a motion phase may include first physiological motion data and second physiological motion reflecting a physiological motion during the motion phase. The first physiological motion data and the second physiological motion data may be collected via a medical imaging device and a first motion sensor, respectively. The system may also direct a radiotherapy device to deliver a radiation treatment to the subject according to a treatment plan. During the radiation treatment, the system may obtain target physiological motion data reflecting the physiological motion of the subject, the target physiological motion data being collected via a second motion sensor; and adjust the treatment plan to adapt to the physiological motion of the subject.

Abstract: Systems and methods for digital radiography are provided. The method may be implemented on the implemented on a DR system including an imaging device and a computing device. The computing device may include at least one processor and at least one storage device. The method may include directing multiple dose sensors to detect a dose of radiation rays emitted from a radiation source of the imaging device. The multiple dose sensors may correspond to multiple imaging detectors, respectively. The method may also include determining the dose of the radiation rays. The method may further include directing, based on the dose of the radiation rays, at least one imaging detector of the multiple imaging detectors to proceed to detect the radiation rays for generating an image of a target object to be examined.

Abstract: The present disclosure provides systems and methods for medical imaging. The system may obtain a scout image of a subject lying on a scanning table. The scanning table may include N portions corresponding to N bed positions of a target scan, and an ith portion of the N portions may correspond to an ith bed position of the N bed positions. For the ith bed position, the system may determine one or more body parts of the subject located at the ith portion of the scanning table based on the scout image; and determine at least one scanning parameter or reconstruction parameter corresponding to the ith bed position based on the one or more body parts of the subject.

Abstract: Systems and methods for MRI are provided. The methods may include for each slice of a plurality of slices of a subject to be scanned, determining a plurality of radiofrequency (RF) parameters, the plurality of RF parameters including at least one channel parameter corresponding to each of a plurality of channels; determining a slice group based at least in part on the RF parameters corresponding to the plurality of slices, the slice group including at least two slices selected from the plurality of slices; and directing at least a portion of the plurality of channels to excite the slice group based on RF parameters corresponding to the slice group.

Abstract: The present disclosure relates to systems and methods for image processing. The method may include obtaining a first image and a second image of a first modality of a target object. The first image may correspond to a first state of the target object, and the second image may correspond to a second state of the target object. The method may include obtaining a third image of a second modality of the target object. The third image may correspond to the first state of the target object. The method may further include determining, based on the first image, the second image, the third image, and an image processing model, a fourth image of the second modality of the target object under the second state.

Abstract: The present disclosure provides systems and methods for motion correction of a positron emission computed tomography (PET) image. The method may include: obtaining scanned images of a scanned object generated at a plurality of time points; and determining a parametric image by performing a correction processing on the scanned images, wherein the correction processing may be configured to correct an influence of a motion of the scanned object on the scanned images.

Abstract: Provided are a system and a method for positron emission computed tomography (PET) image reconstruction. The method may be implemented on a computing device having at least one processor and at least one storage device, comprising: determining correction data based on original PET data (210); determining reconstruction data to be reconstructed based on the correction data (220); and generating, based on the reconstruction data, one or more of a PET reconstruction image and a PET parametric image (230).

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: A system for data synchronization is provided. The system may include a workstation, a user terminal, and a storage device that is accessible to the user terminal and the workstation. The workstation may be configured to generate an identifier relating to a subject. The identifier may point to a data address in the storage device that stores data relating to the subject. The user terminal may be configured to acquire image data of the subject from the data address based on the identifier, receive a user input with respect to the image data of the subject, and update the image data stored in the data address based on the user input.

Abstract: The present disclosure relates to a system for radiation therapy. The system may include a magnetic resonance imaging (MRI) apparatus and a radiation therapy apparatus. The MRI apparatus may be configured to acquire magnetic resonance imaging data with respect to a region of interest (ROI). The radiation therapy apparatus may be configured to apply therapeutic radiation to at least one portion of the ROI when rotating with a gantry. The radiation therapy apparatus may include an eddy current reduction apparatus coupled to the gantry. The eddy current reduction apparatus may include at least one structure, wherein each of the at least one structure may include a plurality of internal structures and at least some of the plurality of internal structures are electrically disconnected from each other.

Abstract: The embodiments of the present disclosure provide a system, a method, and a medical imaging device for acquiring a physiological signal of a target. The system may include a projection module configured to project a structured light to a designated region of the target; an acquisition module configured to acquire a reflected structured light formed by the structured light reaching the designated region; and a processing module configured to determine the physiological signal of the target based on the acquired reflected structured light.

Abstract: A high voltage generator is provided. The high voltage generator includes an inverter bridge including a first bridge leg and a second bridge leg, a first resonant branch coupled in series to the first bridge leg, a transformer coupled in series between the first resonant branch and the second bridge leg, a second resonant branch coupled in series with the transformer, and a rectifier circuit coupled with the transformer for providing an output voltage to an X-ray source.

Abstract: A method and system for metal artifacts correction are provided. The method may include obtaining an image to be processed including metal portion; determining initial projection data by performing data restoration on the metal portion of the image to be processed; determining target projection data by filtering the initial projection data; and determining a target image based on the target projection data.

Abstract: The present disclosure directs to a system and method for configuring a pulse sequence in MRI. The method may include obtaining a preliminary gradient pulse configuration, wherein the preliminary gradient pulse configuration relates to a portion of a pulse sequence to be implemented by one or more coils of an MR scanner, the pulse sequence including a plurality of gradient pulses. The method may also include determining a global peripheral nerve stimulation (PNS) value of the preliminary gradient pulse configuration according to a PNS model. The method may further include determining a target gradient pulse configuration based at least in part on the preliminary gradient pulse configuration, the global PNS value, and a PNS threshold.

Abstract: The present disclosure relates to an insert system for performing positron emission tomography (PET) imaging. The insert system can be reversibly installed to an existing system, such that PET functionality can be introduced into the existing system without the need to significantly modify the existing system. The present disclosure also relates to a multi-modality imaging system capable for conducting both PET imaging and magnetic resonance imaging (MRI). The PET and MRI imaging can be performed simultaneously or sequentially, while the performance of neither imaging modality is compromised for the operation of the other imaging modality.

Abstract: Methods for image processing are provided in the present disclosure. The methods may include obtaining initial k-space data generated by a magnetic resonance imaging device; generating first processed k-space data by padding k space of the initial k-space data with predetermined data; generating second processed k-space data based on the initial k-space data; determining, based on the initial image or the initial k space data, a first weight matrix corresponding to the first processed k-space data and a second weight matrix corresponding to the second processed k-space data, the first weight matrix and the second weight matrix being associated with a quality factor of the initial image; generating target k-space data based on the first processed k-space data, the second processed k-space data, the first weight matrix, and the second weight matrix; and reconstructing a target image based on the target k-space data.