A dual-energy CT image iterative reconstruction method

Abstract

The invention discloses an iterative reconstruction method of a dual-energy spectrum CT image, which is used for reconstructing a base material density image of a measured object. The method includes: 1) selecting a calibration phantom containing two different base materials according to the size and material of the measured object; measuring the phantom through a dual-energy spectrum CT system, and calibrating and expressing the polychromatic projection value and the thickness of the base material The dual-energy spectrum polychromatic forward projection equation of the curve relationship between the combinations; 2) use the dual-energy spectrum CT system to scan the measured object, and collect the dual-energy spectrum polychromatic projection data of the measured object; (3) according to the calibrated multi-color The color orthographic projection equation is used to construct an iterative format. By comparing with the measured multi-color projection data and adding physical constraints, iteratively reconstructs the double-base material density image of the measured object. Compared with the existing method, the method of the present invention does not need to pre-determine the high and low energy spectra of the dual-energy CT system and the attenuation coefficient of the base material, and is applicable to the situations where the high and low energy projections are geometrically matched or not matched.

Description

technical field [0001] The invention relates to the technical field of X-ray CT imaging, in particular to a method for iterative reconstruction of a dual-energy spectrum CT image. Background technique [0002] X-ray computed tomography (X-ray CT for short) is a technology that uses the principle of interaction between X-rays and matter to image the internal information of objects. Since the first X-ray medical CT came out in 1967, X-ray CT technology has developed rapidly. Various CT devices have brought revolutionary changes to medical diagnosis and treatment, and have become routine detection methods for many diseases. CT technology has also become an important industrial support technology, widely used in non-destructive testing of key components in industries such as automobiles, ships, aircraft, electronics, and petroleum. Traditional single-energy spectrum X-ray CT uses one X-ray energy spectrum to scan the measured object, and the CT reconstruction images of differe...

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Problems solved by technology

[0004] The present invention provides a dual-energy spectrum CT image iterative reconstruction method, which is used to solve the problem that the quality of the dual-energy spectrum CT image reconstructed by the traditional image domain decomposition method is significantly reduced when the collected high-energy and low-energy spectrum projection geometric parameters are inconsistent in the prior art. The problem

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