A de-convolution process is applied to an MR, CT or other image (25) of a scanned-object (23) to derive the point-spread function (22') at an object-edge and to pin-point from the mid-point of its full-width-half-maximum FWHM, the location (30) of the true image-edge. With the object-image (25') overlying the PSF function (22') in the de-convolution space, sub-pixels which follow location (30) are transferred to before it to re-construct the image-edge (25') for sharper conformity to the object-edge (23). Sharp definition of image-contour (37) facilitates accurate determination of area and volume of image profiles (35) and their segmentation. The accurate image-edge definition enables viable correction of geometrical distortion in stand-alone MR diagnosis and treatment planning.
Three-dimensionally reconstructed images are not ideal due to blur or smear that is caused by various sources in an X-ray CT scanner. In order to substantially minimize the blur in the three-dimensionally reconstructed image, a known PSF is weighed according to a combination of predetermined parameters. The parameters include two types of information. One group of the parameters is related to device characteristics of the scanner device while the other is related to the scanning conditions of a particular scan. The improvement is performed in any combination of the X, Y and Z directions. The improved PSF's are used to de-convolute the three-dimensionally reconstructed CT image. As a result, the blur and smear are substantially removed from the three-dimensionally reconstructed image data for good visualization as well as accurate physical measurements in the scanned image. The improved techniques according to the current invention are applicable to two-dimensional image data.
A method for reconstructing image data from measured sinogram data acquired from a CT system is provided. The CT system is configured for industrial imaging. The method includes pre-processing the measured sinogram data. The pre-processing includes performing a beam hardening correction on the measured sinogram data and performing a detector point spread function (PSF) correction and a detector lag correction on the measured sinogram data. The pre-processed sinogram data is reconstructed to generate the image data.
A super-resolution processor includes a storage section for storing data of point spread functions of an X-ray CT scanner which are acquired using a phantom and a super-resolution processing section performing super-resolution of image data of a sample generated by the X-ray CT scanner using the stored point spread functions.
Methods and devices for improving the machine-to-machine and temporal (e.g., inter and intra-machine) and database consistency of coronary calcium scoring by applying a filtering algorithm that sharpens and/or smoothes the image so as to return a filtered image having a spatial resolution of a certain reference value.
The present invention provides methods and software for improving thresholding of coronary calcium scoring. In exemplary embodiments, the present invention applies an automatic search algorithm to slice images of an image scan to generate an individualized signal threshold for each particular patient. In other embodiments, an individualized signal threshold is generated for each slice image of the image scan.
