Method for reestablishing conical bundle CT of three-source saddle line track accurately

Abstract

The invention discloses a three-source saddle line trajectory cone beam CT accurate reconstruction method in the field of biomedical imaging technology, which adopts the structure of three X-ray sources and three detectors, and each X-ray source is carried out along its own saddle line trajectory Scanning, the corresponding detector collects projection data, and multiple saddle line trajectories have intersections with each other. These intersections divide the collected projection data into several intervals, and the data in each interval is Hilbert filtered according to the set direction. Finally, back-projection reconstruction is performed on the filtered data to obtain the reconstructed image. The present invention has high reconstruction precision and fast imaging speed, and the algorithm has a shift-invariant property when filtering projection data, that is, when the projection data on the detector is subjected to Hilbert filtering, it is only related to the position of the current X-ray source, and is related to The measured object is irrelevant; the projection data acquisition speed is fast, and the data acquisition time is only one-third of that of single-source CT.

Description

technical field [0001] The invention relates to an imaging method in the technical field of image processing, in particular to a multi-source saddle line trajectory cone beam CT accurate filter back projection reconstruction method. Background technique [0002] The working principle of cone-beam CT is as follows: the X-ray tube emits cone-beam X-rays at one point. After passing through the object to be measured, the attenuated X-rays are detected by the detector on the opposite side, and the X-rays are converted into electricity. The signal is sent to the computer's analog-to-digital converter and data collector, converted into a digital signal and stored in the computer. This is just one exposure and acquisition process. In order to obtain the projection data needed to reconstruct the measured object, the X-ray source needs to scan along a certain trajectory, and complete an exposure and data acquisition process at each position. From the point of view of the scanning tra...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the acquisition speed of projection data is slow. Since there is only a single X-ray source, the image of the measured object can be completely reconstructed only after it completes a cycle of scanning along the saddle line.

In some occasions, the state of the measured object changes rapidly with time, and the data acquisition speed of single-source CT cannot meet the needs at this time, resulting in serious motion artifacts in the reconstructed image

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