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: 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 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: 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 periodical 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: 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: A method and an apparatus for scanning with a lowered dose are provided. The method includes: determining a dynamic changing model of a prepatient collimator according to a rotation angle of a tube in a scanning mode; in a case that the scanning mode is a normal scan, controlling an opening angle of the prepatient collimator according to the dynamic changing model of the prepatient collimator at an initial stage and an end stage of the normal scan; and in a case that the scanning mode is a scan with phase control, controlling an opening angle of the prepatient collimator according to the dynamic changing model of the prepatient collimator at an initial stage and an end stage of a phase of the scan with phase control.

Abstract: A method and apparatus of image compensation are provided. The method may include: calculating an overlapping position between two adjacent scannings; obtaining two images at the overlapping position of the two adjacent scannings, and calculating mutual information of the two images by using a three dimensional non-rigid registration method; and acquiring a corresponding transformational matrix when the mutual information reaches a threshold, and compensating one of the two scans which needs to be compensated by using the transformational matrix. Images at the overlapping position of two neighboring scannings can be used to find a motion law at an identical z position of the two adjacent scannings and to obtain a corresponding match factor. Thus inconsistence of images caused by a patient's movement can be compensated.

Abstract: A method for collecting multi-energy CT data is provided. A method of reconstruction from multi-energy CT scan is further provided, in which data collection is performed on the first-class object at voltage values of m sampling points of the first-class voltage varied periodically, to obtain n sets of multi-energy first-class scan data {yi}; and a data collection is performed on a double-cylinder correction phantom at the voltage values of m sampling points to obtain combination coefficients, and thus obtaining corresponding combination coefficients Cifirstand Cisecondcorresponding to the case that the first-class scan data is collected in the ith projection angle at the first-class voltage; and the image vectors Xfirst and Xsecond are obtained by calculating a minimum value of the difference between the first-class scan data {yi} and the combination projection data CifirstPi*Xfirst+CisecondPi*Xsecond.

Abstract: A method and an apparatus for scanning with a lowered dose are provided. The method includes: determining a dynamic changing model of a prepatient collimator according to a rotation angle of a tube in a scanning mode; in a case that the scanning mode is a normal scan, controlling an opening angle of the prepatient collimator according to the dynamic changing model of the prepatient collimator at an initial stage and an end stage of the normal scan; and in a case that the scanning mode is a scan with phase control, controlling an opening angle of the prepatient collimator according to the dynamic changing model of the prepatient collimator at an initial stage and an end stage of a phase of the scan with phase control.

Abstract: A method and apparatus of image compensation are provided. The method may include: calculating an overlapping position between two adjacent scannings; obtaining two images at the overlapping position of the two adjacent scannings, and calculating mutual information of the two images by using a three dimensional non-rigid registration method; and acquiring a corresponding transformational matrix when the mutual information reaches a threshold, and compensating one of the two scans which needs to be compensated by using the transformational matrix. Images at the overlapping position of two neighboring scannings can be used to find a motion law at an identical z position of the two adjacent scannings and to obtain a corresponding match factor. Thus inconsistence of images caused by a patient's movement can be compensated.

Abstract: A method for collecting multi-energy CT data is provided. A method of reconstruction from multi-energy CT scan is further provided, in which data collection is performed on the first-class object at voltage values of m sampling points of the first-class voltage varied periodically, to obtain n sets of multi-energy first-class scan data {1}; and a data collection is performed on a double-cylinder correction phantom at the voltage values of m sampling points to obtain combination coefficients, and thus obtaining corresponding combination coefficients Cfirsti and Csecondi corresponding to the case that the first-class scan data is collected in the ith projection angle at the first-class voltage; and the image vectors Xfirst and Xsecond are obtained by calculating a minimum value of the difference between the first-class scan data {yi} and the combination projection data CfirstiPi*Xfirst+Csecondi*Xsecond.