Method for iterating and reconstructing double-energy-spectrum CT image

Abstract

The invention discloses a method for iterating and reconstructing a double-energy-spectrum CT image. The method is used for reconstructing a base material density image of a measured object and comprises the following steps of (1) selecting a calibration model body containing tow types of different base materials according to the size of a material of the measured object; measuring the model body through a double-energy-spectrum CT system, and calibrating a double-energy-spectrum multi-color orthographic projection equation presenting a curvilinear relationship between a multi-color projection value and base material thickness combination; (2) collecting double-energy-spectrum multi-color projection data of the measured object by utilizing the double-energy-spectrum CT system; (3) constructing a iterative scheme according to the calibrated multi-color orthographic projection equation, and iterating and reconstructing the double-base-material density image of the measured object through comparison with the practically measured multi-color projection data and addition of a physical constraint condition. Compared with the existing method, the method for iterating and reconstructing the double-energy-spectrum CT image has the advantages that the high energy spectrum and the low energy spectrum of the double-energy-spectrum CT system and an attenuation coefficient of the base materials do not need to be detected in advance, and meanwhile the method is applied to the situation that the high energy spectrum and the low energy spectrum are matched with each other or not in geometry.

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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