A method of generating a tomographic image includes radiating X-rays onto an object and acquiring X-ray data by detecting the X-rays passed through the object; generating a first tomographic image by reconstructing the X-ray data; identifying, in the first tomographic image, a first region corresponding to a metal particle included in the object; generating a second tomographic image by changing a pixel value of the first region to a predetermined value; acquiring first projection data by performing forward projection on the second tomographic image; generating second projection data by performing interpolation on first signal intensity values corresponding to the first region, based on the first projection data; generating reconstruction data by subtracting the first projection data from the second projection data; generating a third tomographic image based on the reconstruction data; and generating a fourth tomographic image based on the third tomographic image and the first tomographic image.

A method for the reduction of streak artifacts in an image data set reconstructed from projection images of an X-ray device is provided. The method includes determining a first interim data set by applying a non-linear low-pass filter to pixels that satisfy a selection condition. A second non-linear, high-pass-filtered interim data set is determined by pixel-by-pixel subtraction of the first interim data set from the image data set. The second interim data set is Fourier transformed in order to obtain a spatial frequency data set. Frequency portions attributable to artifacts in the spatial frequency data set are removed, and the processed spatial frequency data set is inverse Fourier transformed, such that a third interim data set is obtained. An artifact-reduced result data set is determined by addition of the third interim data set and the first interim data set.

Methods for reconstruction of a volume radiographic image acquire 2-D projection images of a subject at a plurality of acquisition angles and generate an initial 3-D volume image formed of image voxels according to the acquired 2-D projection images. An initial 3-D reconstruction metal mask is formed from voxels that have attenuation to x-rays indicative of metal. At least one voxel is removed from the initial 3-D reconstruction metal mask to form a refined 3-D reconstruction metal mask according to a distribution of pixel values that contribute to the corresponding data value for the at least one voxel. One or more 2-D projection images are modified according to the distribution of pixel values. A refined 3-D volume image is generated according to the modified 2-D projection images. A rendering of the refined 3-D volume image displays that includes at least a portion of the refined 3-D reconstruction metal mask.

A method for artifact correction in computed tomography, the method including: (1) acquiring a plurality of data sets associated with at least one low X-ray energy, and at least one high X-ray energy; (2) generating a plurality of preliminary images from the plurality of data sets; (3) identifying sources of an artifact source image; (4) forward projecting the artifact source image to produce artifact source data; (5) selecting and combining the plurality of data sets acquired in order to produce a new subset of data associated with the artifact, whereby to produce artifact reduced data; (6) generating a repaired data set to keep data sets associated with the low X-ray energy in artifact-free data and to introduce data sets associated with the high X-ray energy in regions impacted by an artifact; and (7) generating a final reduced artifact image from the repaired data set.

A method for reducing metal artifacts in a volume radiographic image acquires a first set of projection images of an object on a radiographic detector at different acquisition angles. An initial estimate of the volume that includes the object using the acquired projection images is generated. The estimated volume is updated by one or more iterations of generating a second set of scatter-corrected projection images using the acquired first set of projection images and the estimated volume; generating a third set of estimated projection images using forward ray-tracing through the estimated volume; and reconstructing the estimated volume according to a signal quality factor obtained from analysis of the detector signal and used in a comparison of the second set of scatter-corrected projection images with the third set of estimated projection images. One or more images rendered from the updated estimated volume are displayed.

A production method for test X-ray includes preparation (S10) of first CT data (B) of an inspection object, second CT data (BM) for metal portions of the inspection object, and third CT data (TM) for metal portions of a target object, transformation (S20) of the first, second, and third CT data (B, BM, TM) from the image space (BR) into corresponding first sinogram data (SB), second sinogram data (SBM), and third sinogram data (STM) in the radon space (RR), calculation (S30, S40) of the artifact sinogram data (SA), back-transformation (S50) of the artifact sinogram data (SA) from the radon space (RR) into the image space (BR) in CT artifact data (A) for the artifacts that are to be inserted, and insertion of the CT artifact data (A) into the first CT data (B).

A method is for metal artifact reduction in CT image data, the CT image data including multiple 2D projection images acquired using different projection geometries and suitable to reconstruct a 3D image data set of a volume of an imaged object. In an embodiment, the method includes a metal artifact reduction process including at least, acquiring, using a multi-energy CT technique, energy-resolved CT image data associated with multiple energy ranges. At least one result of the multi-energy technique is used in at least one aspect of the metal artifact reduction process.

A medical image processing apparatus and a medical image processing method that can reduce the noise bias of a corrected image in which high absorber artifacts included in a reconstructed image are corrected. The medical image processing apparatus has an arithmetic unit for correcting high absorber artifacts. The arithmetic unit comprises: a projection data generating section that generates projection data corresponding to a high absorber area in a reconstructed image with high absorber artifacts; a noise image generating section that generates a noise image using the projection data; and a weighted combining section that makes a weighted combining of the noise image with a corrected image in which high absorber artifacts are corrected.

A low-dose imaging method includes receiving a sparse image set of a portion of a patient's anatomy; up-sampling the sparse image set, in the sinogram domain and using a first neural network, to yield an up-sampled sinogram; generating, from the up-sampled sinogram, an initial reconstruction; and removing, from the initial reconstruction and using a second neural network, one or more artifacts in the initial reconstruction to yield a final output volume.

A method for determining image values in marked pixels of at least one projection image is provided. The at least one projection image is part of a projection image set provided for reconstruction of a three-dimensional image dataset and acquired in each case using a projection geometry in an acquisition procedure. The image values are determined through evaluation of at least one epipolar consistency condition that is to be at least approximately fulfilled, that results from the projection geometries of the different projection images of the projection image set, and that requires the agreement of two transformation values in transformation images determined from different projection images by Radon transform and subsequent derivation as a condition transformation.