Tomography-based calibration method of geometric position relationship of X-ray machine and detector

Abstract

The invention provides a calibration method of the geometric position relationship of an X-ray machine and a detector. The calibration method includes: placing at least two small balls in an imaging zone and recording the distance d between the two small balls and the distance between the two small balls and the plane where the detector is located respectively; randomly selecting one from many digital X-ray projection drawings, and recording the projection positions C and D corresponding to the position information of the two small balls A and B; estimating the initial X coordinate Px and the initial Y coordinate Py of the X-ray machine, and calculating the Z coordinate Pz of the X-ray machine according to the geometric imaging relationship; calculating the X coordinates Ax and Bx and the Y coordinates Ay and By of the two small balls according to the geometric imaging relationship and the Z coordinate Pz of the X-ray machine; obtaining the positions of the X-ray machine in the digital X-ray projection drawing according to the geometric imaging relationship by aid of the three-dimensional coordinates and the projections C and D of the two small balls A and B.

Description

technical field [0001] The invention belongs to the field of radiation imaging, in particular to a method for calibrating the relative geometric position relationship between an X-ray machine and a detector based on tomographic imaging. Background technique [0002] X-ray tomographic imaging technology has been widely used in clinical medicine, such as breast tomography, dental tomography and so on. [0003] A typical tomography system is generally composed of X-ray machines, detectors, mechanical transmissions, electronic computers, etc. During the imaging process, the X-ray machines are controlled by mechanical devices to move on specific tracks, and the detectors are generally placed on specific The position is fixed, and after a series of projections are taken, a specific reconstruction algorithm is used to reconstruct the collected data to obtain the three-dimensional structure information of the object. In the process of image reconstruction, apart from the reason of ...

AI Technical Summary

Problems solved by technology

In the process of image reconstruction, apart from the reasons of the algorithm itself, the exact positional relationship between the detector and the X-ray machine will have a great impact on the quality of the reconstructed image

[0004] In a typical tomographic imaging system, although the X-ray machine is fixed and moved on a specific track by a mechanical device, the relative position between the light machine and the detector is often not fixed, which leads to inaccurate accuracy during the imaging process. It is necessary to know the relative positional relationship between the detector and the X-ray machine at each exposure, and this uncertain relationship will directly lead to the inability to obtain ideal reconstructed images

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