Calibration method of geometric position relationship between X-ray machine and detector based on tomography

Abstract

The invention provides a method for calibrating the geometric position relationship between an X-ray machine and a detector, which includes: placing at least two small balls in the imaging area, and recording the distance d between the two small balls and the distance between the two small balls and the detector respectively. The distance between the planes of the X-ray machine; choose one of the digital X-ray projection pictures arbitrarily, and record the projection positions C and D corresponding to the position information of the two small balls A and B; estimate the initial X coordinate P of the X-ray machine x and the Y coordinate P y , and calculate the Z coordinate P of the X-ray machine according to the geometric imaging relationship z ;According to the geometric imaging relationship and the Z coordinate P of the X-ray machine z , calculate the X and Y coordinates A of the two balls x 、A y and B x , B y ; Utilize the three-dimensional coordinates of the two small balls A, B and the projections C, D of the two small balls A, B, and obtain the position of the X-ray machine in all digital X-ray projection diagrams according to the imaging geometric relationship.

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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