Analytic method for eliminating metal artifact of CT image

Abstract

The invention provides an analytic method for eliminating a metal artifact of a CT image. With the method, the iterative operation can be avoided. The method comprises: a metal image is segmented from an image reconstructed based on projection data on the multi-energy-spectrum-ray condition; a projection image is solved; an approximate value of an energy spectrum function is searched; an expression of an artifact function is obtained and an artifact image is obtained; the artifact image is subtracted from an original image to obtain a corrected image as shown in an attached drawing. The method is characterized in that the band shaped artifact can be eliminated and the structural feature of original information can be kept; and no priori knowledge of the energy spectrum and original projection data are needed according to the correction method and the reconstruction speed is fast.

Description

technical field

[0001] The present invention mainly relates to the field of medical X-ray computed tomography (Computed Tomography, referred to as CT), and specifically relates to medical CT detection and imaging. The reconstructed CT image has metal artifacts. Background technique

[0002] CT detection imaging technology can non-destructively obtain tomographic images of objects, and plays an irreplaceable important role in medical aided diagnosis. Ideally, the projection data measured by the scanning system of CT equipment is the line integral of the linear attenuation coefficient of the material, and CT The reconstruction system of the device uses the line integral data for image reconstruction to obtain CT images that can be used for clinical diagnosis. However, in actual CT scans, the projection data obtained by the system usually contain various errors, such as errors caused by metal objects, which It will cause artifacts in the reconstructed image, reduce the image q...

Examples

Embodiment Construction

[0025] The present invention mainly provides a method for reducing metal artifacts in CT images, including obtaining projection data, image reconstruction, segmenting metal objects, re-projection, data processing, artifact image reconstruction and obtaining corrected images. The goal is to eliminate banding Artifacts retain the structural features of the original information, obtain high-resolution CT images, and provide more accurate information for clinical diagnosis. Embodiments of the present invention: first obtain the projection data under the multi-energy spectrum and perform image reconstruction; then perform image segmentation Get the image of the metal object, and find its Radon transformation; process the Radon transformation data through the proposed analytical method, and reconstruct the processed data to obtain the artifact image; subtract the artifact image from the original image to obtain the corrected CT Image; give embodiment at last. Concrete steps are as fo...

technical field

[0001] The present invention mainly relates to the field of medical X-ray computed tomography (Computed Tomography, referred to as CT), and specifically relates to medical CT detection and imaging. The reconstructed CT image has metal artifacts. Background technique

[0002] CT detection imaging technology can non-destructively obtain tomographic images of objects, and plays an irreplaceable important role in medical aided diagnosis. Ideally, the projection data measured by the scanning system of CT equipment is the line integral of the linear attenuation coefficient of the material, and CT The reconstruction system of the device uses the line integral data for image reconstruction to obtain CT images that can be used for clinical diagnosis. However, in actual CT scans, the projection data obtained by the system usually contain various errors, such as errors caused by metal objects, which It will cause artifacts in the reconstructed image, reduce the image q...

Examples

Embodiment Construction

[0025] The present invention mainly provides a method for reducing metal artifacts in CT images, including obtaining projection data, image reconstruction, segmenting metal objects, re-projection, data processing, artifact image reconstruction and obtaining corrected images. The goal is to eliminate banding Artifacts retain the structural features of the original information, obtain high-resolution CT images, and provide more accurate information for clinical diagnosis. Embodiments of the present invention: first obtain the projection data under the multi-energy spectrum and perform image reconstruction; then perform image segmentation Get the image of the metal object, and find its Radon transformation; process the Radon transformation data through the proposed analytical method, and reconstruct the processed data to obtain the artifact image; subtract the artifact image from the original image to obtain the corrected CT Image; give embodiment at last. Concrete steps are as fo...

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