Cone-beam CT beam hardening calibration method based on registration model emulation

Abstract

The utility model discloses a beam hardening correction method of cone beam CT based on registration model simulation, which acquires multi-color projection data through circle locus cone beam CT scanning to a spare part. After acquiring CT images of sequence slices by cone beam CT reconstitution to the multi-color projection, the contour of certain pieces of the images are extracted so that a measurement point formed a plurality of closed contour lines is acquired. Projection simulation is processed after the registration of the measurement point and the CAD model of the part, and then the length of the part passing through the part at every imaging point is acquired. A hardening curve that passes through the original point is acquired by nonlinear fitting and a straight line that passes through the original point is acquired by linear fitting. The beam hardening constructed defect of the cone beam CT is corrected according to the hardening curve and the rectifying straight line. The utility model is flexible in application, and can approximately corrected through multi-color projection to unique color projection, and the beam hardening artifacts is reduced obviously after correction.

Description

technical field [0001] The invention relates to a cone-beam CT beam hardening correction method, which belongs to the technical field of CT. Background technique [0002] Cone-Beam Computed Tomography (CBCT) uses a cone-beam ray source and an area array detector to collect projection data of the measured object. It is a three-dimensional CT technology developed in recent years. Compared with traditional two-dimensional CT, cone-beam CT has a very high scanning speed, and the reconstructed slice images record the distribution of physical parameters such as material and density of each point inside the object, and have continuous slice sequence, intra-slice and inter-slice With the characteristics of the same spatial resolution and high precision, it has shown broad application and development prospects in the fields of reverse engineering and industrial internal vision. [0003] In the cone-beam CT system, the X-rays emitted by the ray source have a certain range of energy d...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the deficiencies of the existing technology that is not flexible enough to be applied effectively to cone beam CT, the present invention provides a new method for beam hardening correction of cone beam CT based on registration model simulation, so as to apply cone beam CT to the actual non-destructive Effectively correct for beam hardening problems that occur during inspections

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