摘要:
The present invention is directed to a method of MR imaging whereby a k-space blade extending through a center of k-space from a subject in motion is acquired. A high-pass convolution of the k-space blade with a reference k-space blade is then determined and converted to a δ function. In-plane motion of the subject during data acquisition of the k-space is then determined from the δ function.
摘要:
The present invention is directed to a method of MR imaging whereby a k-space blade extending through a center of k-space from a subject in motion is acquired. A high-pass convolution of the k-space blade with a reference k-space blade is then determined and converted to a δ function. In-plane motion of the subject during data acquisition of the k-space is then determined from the δ function.
摘要:
A method for processing digital images includes acquiring a phase difference image which includes one or more phase wraps, creating a modulated phase difference image from the phase difference image, comparing the modulated phase difference image to the phase difference image to locate areas in the phase difference image to be unwrapped, and unwrapping the phase difference image based on the areas located in the comparing step. The unwrapping step is performed by replacing wrapped pixels in the phase difference image with pixels in the modulated phase difference image plus an integer multiple of &pgr;. The integer multiplier is computed by comparing overlapping pixels in the image segments. This has a smoothing effect causing the wrapped pixels in the phase difference image to become unwrapped. As a result of this pixel replacement process, an image of improved quality and information content is produced compared with conventional methods.
摘要:
The present invention is a directed to method and system of TCT imaging whereupon data associated with unmeasured or inadmissible transducer locations is determined from data acquired at measured or admissible transducer locations. The invention analyzes measured TCT data associated with several transducer locations to provide an estimate of unmeasured data so as to complete a full data set for image reconstruction. In this regard, by measuring TCT data at many points on the surface of a hemispherical bowl or sphere in which an imaging object is placed, mathematical coefficients may be determined for the TCT data as a function of transducer location. From these coefficients, the unmeasured transducer locations may be evaluated such that data associated with the unmeasured transducer locations may be estimated and utilized for image reconstruction to improve image quality as well as improve the diagnostic sensitivities or capabilities of the TCT system.
摘要:
To perform cone beam reconstruction by using projection data correctly corresponding to X-ray beam having passed through each pixel in the reconstruction area, data D1 is obtained which is plane projected to a plane based on projection data D0. Then, plane projection data D1 to the projection plane pp is projected to the reconstruction area in the direction of X-ray transmission to obtain back projection pixel data D2. Thereafter, back projection pixel data D2 will be added for each corresponding pixel for all views to obtain back projection data D3. The present invention provides reconstruction by device of projection data correctly corresponding to the X-ray beam having passed through the reconstruction area. Through the plane projection to a plane the operation will become simplified and faster.
摘要:
The present invention is directed to a method and system of TCT imaging whereupon an exact inversion formula is used for reconstruction of TCT data. The present invention utilizes inversion formulae that are of the filtered backprojection and ρ-filter types.
摘要:
A method for reconstructing an image of an object utilizing a computed tomographic (CT) imaging system is provided. The CT system includes a radiation source and a multislice detector array on a rotating gantry, with the radiation source configured to project a beam of radiation through an object and towards. the multislice detector array. The multislice detector array is configured to sense attenuation of the radiation passing through the object. The method for reconstructing an image includes helically scanning an object with a computed tomographic imaging system to acquire a plurality of views of projection data at a plurality of gantry angles and a plurality of cone angles, generating a plurality of cone angle dependent weights that are inversely correlated to an absolute value of a cone angle, and weighting the projection data using the cone angle dependent weights.
摘要:
The present invention is, in one embodiment, a method for multi-slice, computed tomography imaging. The method includes steps of moving an x-ray source through a trajectory; projecting an x-ray cone beam from the moving x-ray source through an object towards a curved detector; and determining contributions of segments along the trajectory to voxels in a reconstruction volume of the object, including compensating the determined contributions for curvature of the detector and x-ray cone beam geometry.
摘要:
The present invention is in one embodiment a method of processing projection data collected in a helical scan performed along a helical trajectory relative to an object being scanned. The method includes steps of defining a coordinate system to parameterize the data and generating estimates of projection data not on the helical trajectory by solving ultrahyperbolic equations in the defined coordinate system.