摘要:
Methods and systems for controlling x-ray exposure during a dynamic pitch helical scan using a translatable table are provided. The system includes a collimator positioned between an x-ray source and an object to be scanned configured to shutter an x-ray fan beam generated by the x-ray source to at least one of translate the x-ray fan beam along a z-axis of the scan and vary the width of the x-ray beam along the z-axis, and a collimator controller configured to dynamically position the collimator using at least one of predetermined trajectory of the translatable table and a current position of the translatable table.
摘要:
A method for reconstructing image data from acquired tomographic projection data measurements is provided. The projection data measurements comprise one or more missing data measurements. The method comprises generating a coarse-resolution projection data set from the acquired projection data measurements and performing an iterative reconstruction on the coarse-resolution projection data set to generate a coarse-resolution reconstructed data set. Then, the method comprises reprojecting the coarse-resolution reconstructed data set to obtain one or more estimates for the one or more missing data measurements. The one or more estimated missing data measurements are then recombined with the acquired projection data measurements, to generate a recombined data set. Then, a direct reconstruction algorithm is applied to the recombined data set to generate the reconstructed image data.
摘要:
A technique is provided for improving z-axis coverage and/or reducing cone beam artifacts during CT imaging. Multiple X-ray emission points are provided along the z-axis. Some or all of the emission points may be concurrently active. X-rays from concurrently active emission points are collimated so that X-rays from two or more emission points do not overlap on the detector. In addition, different groups of concurrently activated emission points may be sequentially or alternately activated, in conjunction with collimation, to prevent the overlap of X-rays from different emission points on the detector. In this manner, The X-rays may be timed and collimated such that the respective streams of radiation become adjacent at different locations, such as at the detector, the isocenter, or edge of the field of view.
摘要:
Configurations for stationary imaging systems are provided. The configurations may include combinations of various types of distributed sources of X-ray radiation, which generally include addressable emitter elements which may be triggered for emission in desired sequences and combinations. The sources may be ring-like, partial ring-like, or line-like (typically along a Z-axis), and so forth. Combinations of these are envisaged. Corresponding detectors may also be full ring detectors or partial ring detectors associated with the sources to provide sufficient coverage of imaging volumes and to provide the desired mathematical completeness of the collected data.
摘要:
A system and method for ascertaining the identity of an object within an enclosed article. The system includes an acquisition subsystem, a reconstruction subsystem, a computer-aided detection (CAD) subsystem, and an alarm resolution subsystem. The acquisition subsystem communicates view data to the reconstruction subsystem, which reconstructs it into image data and communicates it to the CAD subsystem. The CAD subsystem analyzes the image data to ascertain whether it contains any area of interest. A feedback loop between the reconstruction and CAD subsystems allows for continued, more extensive analysis of the object. Other information, such as risk variables or trace chemical detection information may be communicated to the CAD subsystem to dynamically adjust the computational load of the analysis.
摘要:
A method for imaging an object is provided. The method includes acquiring image data of the object, wherein the image data includes a plurality of original voxels, and identifying, using a processing device, a first subset of voxels from the acquired image data. The method also includes performing a principal component analysis (PCA) on the first subset of voxels and determining whether sheet-like material is present in the object based on the results of the performed PCA on the first subset of voxels.
摘要:
A method for imaging an object is provided. The method includes acquiring image data of the object, wherein the image data includes a plurality of original voxels, and identifying, using a processing device, a first subset of voxels from the acquired image data. The method also includes performing a principal component analysis (PCA) on the first subset of voxels and determining whether sheet-like material is present in the object based on the results of the performed PCA on the first subset of voxels.
摘要:
A method and system for selective resolution improvement in computed tomography (CT) scanning. The method includes receiving scan data representative of a scanned object from a CT scanner and reconstructing the scan data using a first algorithm to create a first set of reconstructed data. A region of interest is identified within the first set of reconstructed data. A portion of the scan data corresponding to the region of interest is reconstructed using a second algorithm to create a second set of reconstructed data. The first set of reconstructed data and the second set of reconstructed data are combined to create combined reconstructed data.
摘要:
A technique is provided for the temporal interpolation of a projection data set acquired of a dynamic object, such as a heart. The projection data set is acquired using a slowly rotating gantry and a distributed X-ray source. The projection data may be interpolated at each view position to a selected instant of time, such as relative to a cardiac phase. The resulting interpolated projection data characterize the projection data at each view location at any instant in time. The set of interpolated projection data may then be reconstructed to generate images and/or volume with improved temporal resolution.
摘要:
One or more techniques are provided for adapting a reconstruction process to account for the motion of an imaged object or organ, such as the heart. In particular, projection data of the moving object or organ is acquired using a slowly rotating CT gantry. Motion data may be determined from the projection data or from images reconstructed from the projection data. The motion data may be used to reconstruct motion-corrected images from the projection data. The motion-corrected images may be associated to form motion-corrected volume renderings.