Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A technique is provided for improving consistency between slabs in a reconstructed CT image. Candidate sectors associated with an image slab are determined. If the sectors contain sufficient information to reconstruct the image slab, the sector which minimizes inconsistency with projection data for adjacent image slabs is selected for reconstruction. If the sectors do not contain sufficient information to reconstruct the slab, sectors are merged together until a merge group contains sufficient information. The merge group which minimizes inconsistency with projection data for adjacent image slabs is selected for image reconstruction. The selected sectors or merge groups are then reconstructed with the resulting image slabs comprising a reconstructed image with improved consistency between image slabs.

Abstract: One or more techniques are provided for deriving motion data from a set of CT projection data. The techniques calculate moments associated with consistency conditions for the projection data to derive motion data from the projection data. One aspect of the present techniques uses the calculated moments to select projection data sets based upon the presence or absence of motion between the projection data sets. Periodicity information may then be extracted from the selected projection data sets. Another aspect of the present techniques uses projection data acquired by a slowly rotating volumetric CT gantry to allow the separation of a corruptive signal from a desired motion signal. Once separated, the desired motion signal may be used to identify projection data at a desired phase of motion.

Abstract: A technique is provided for reducing motion-related artifacts present in CT images attributable to the dynamic nature of the imaged tissue or the time-varying concentration of a contrast agent. A region of interest that encompasses a structure of diagnostic significance is selected. For projections acquired by the various rows of detectors in a multi-slice CT imaging system, the portions of the projections attributable to the projection of the region of interest are averaged for each view angle. The projections containing these averaged values are then combined with the projections which do not encompass the region of interest. The combined projection set may be reconstructed to form a CT image of the dynamic tissue. In addition, a smoothing step may be performed to interpolate projection values around the region of interest to smooth the visual transition to the unaveraged portions of the image.

Abstract: 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.

Abstract: One or more techniques are provided for deriving motion data from a set of CT projection data. The techniques calculate moments associated with consistency conditions for the projection data to derive motion data from the projection data. One aspect of the present techniques uses the calculated moments to select projection data sets based upon the presence or absence of motion between the projection data sets. Periodicity information may then be extracted from the selected projection data sets. Another aspect of the present techniques uses projection data acquired by a slowly rotating volumetric CT gantry to allow the separation of a corruptive signal from a desired motion signal. Once separated, the desired motion signal may be used to identify projection data at a desired phase of motion.

Abstract: A technique is provided for minimizing or eliminating motion-related artifacts present in CT images due to the dynamic nature of the imaged tissue or the time-varying concentration of a contrast agent used for imaging. The technique allows for the selection of a region of interest that may encompass a structure of diagnostic interest. For projections acquired by the various rows of detectors in a multi-slice CT imaging system, the portions of the projections attributable to the projection of the region of interest within the detector are averaged for each view angle. The projections containing these averaged values are then combined with the projections which do not encompass the region of interest and the combined projection set may be reconstructed to form a CT image of the dynamic tissue. In addition, a smoothing step may be performed to interpolate projection values around the region of interest to smooth the visual transition to the unaveraged portions of the image.

Abstract: A method for imaging a desired coronary artery or desired portion thereof is provided. The method includes reconstructing a first 2D image of a first desired coronary artery branch segment utilizing a first projection dataset acquired during a first desired cardiac phase of a plurality of cardiac cycles to reduce motion artifacts of the first desired coronary artery branch segment, reconstructing a second 2D image of a second desired coronary artery branch segment utilizing a second projection dataset acquired during a second desired cardiac phase of the plurality of cardiac cycles to reduce motion artifacts of the second desired coronary artery branch segment, and reconstructing at least one 3D image of the coronary artery utilizing the first 2D image and the second 2D image.

Abstract: A technique is provided for positioning a reconstruction window in a CT cardiac image data set. The technique uses ECG data, either concurrently acquired or derived from statistical data sets in conjunction with the patient's heart rate, to allow the placement of reconstruction windows at a desired cardiac phase of interest as selected by an operator. The technique can be used in combination with information about the motion or position of a cardiac feature to optimally image the cardiac feature, such as the right coronary artery. In addition, the technique allows unacceptable data from a cardiac cycle to be discarded to improve the final image quality. By using the ECG data to position the reconstruction window, phase misregistration artifacts may be minimized.

Abstract: A technique is provided for improving consistency between slabs in a reconstructed CT image. Candidate sectors associated with an image slab are determined. If the sectors contain sufficient information to reconstruct the image slab, the sector which minimizes inconsistency with projection data for adjacent image slabs is selected for reconstruction. If the sectors do not contain sufficient information to reconstruct the slab, sectors are merged together until a merge group contains sufficient information. The merge group which minimizes inconsistency with projection data for adjacent image slabs is selected for image reconstruction. The selected sectors or merge groups are then reconstructed with the resulting image slabs comprising a reconstructed image with improved consistency between image slabs.

Abstract: An approach to image reconstruction provides enhanced image quality from limited projection data, particularly when the imaging object (or a portion of interest) is in motion during the tomographic projection data collection process. An interpolated projection view is generated from existing projection views between which an additional relationship exists by virtue of being respectively based on data collected in different data acquisition cycles. The present invention provides a technique for combining the existing projection views into an interpolated projection view by interpolation in time. A further aspect of the invention provides an approach for selecting a reconstruction range for projection data representing the imaged object and covering a plurality of projection ranges.

Abstract: A method for imaging a desired coronary artery or desired portion thereof is provided. The method includes reconstructing a first 2D image of a first desired coronary artery branch segment utilizing a first projection dataset acquired during a first desired cardiac phase of a plurality of cardiac cycles to reduce motion artifacts of the first desired coronary artery branch segment, reconstructing a second 2D image of a second desired coronary artery branch segment utilizing a second projection dataset acquired during a second desired cardiac phase of the plurality of cardiac cycles to reduce motion artifacts of the second desired coronary artery branch segment, and reconstructing at least one 3D image of the coronary artery utilizing the first 2D image and the second 2D image.

Abstract: A method for reconstructing an image of a beating heart includes decomposing at least one electrocardiogram (EKG) RR interval, tagging projection data with cardiac phase information based on the decomposition, and reconstructing an image using the tagged data.

Abstract: A method for reconstructing an image of a beating heart in vivo is described. The method includes acquiring projection data for at least one z-location within a projection space, determining peaks in first order spatial moments for the projection space using the projection data, and reconstructing the image utilizing peaks in the first order spatial moments.

Abstract: One embodiment of the present invention provides a method for imaging a selected coronary artery utilizing a computed tomography (CT) imaging system. The method includes utilizing a data compilation of low motion cardiac phases and corresponding coronary artery branch segments to select a cardiac phase corresponding to the selected coronary artery branch segment. A volume of the patient's heart including the selected coronary artery branch segment is scanned to acquire projection data. The projection data includes data acquired during the selected cardiac phase of a plurality of cardiac cycles. Projection data acquired during the selected cardiac phase is selectively utilized to effectively reduce motion artifacts of the selected coronary artery branch segment on a reconstructed image.