Spiral CT scanning and image-forming method and system

Abstract

The embodiment of the invention provides a spiral CT scanning and image-forming method and system, and belongs to the technical field of CT scanning. The method comprises the following steps: controlling a detector and a ray source to perform primary spiral scanning motion and enabling a scanning rotary table to perform rotational motion; stopping motion of the ray source and the detector when the motion range of the detected ray source and the detector exceeds preset motion range; controlling the ray source and the detector to horizontally move by preset distance in the preset horizontal-moving direction, and setting starting time for secondary spiral scanning motion of the ray source and the detector according to the deflection angle of the scanning rotary table; controlling the ray source and the detector to perform secondary spiral scanning motion in a direction reverse to the preset motion direction; obtaining projection data by moving the ray source and the detector by N-1 preset distances in the preset horizontal moving direction; re-arranging the projection data; performing CT image re-construction on data, and realizing scanning on large objects through synchronous movement of the ray source and the detector. The spiral CT scanning and image-forming method reduces cost of the detector and improves scanning efficiency.

Description

technical field [0001] The present invention relates to the technical field of CT scanning, in particular to a spiral CT scanning imaging method and system. Background technique [0002] Limited by the size and cost of detectors, the main layout of large-scale high-energy industrial CT equipment is still Generation II, Generation III or Generation II+III. The detectors are basically single-row or multi-row linear array detectors, so the detection The efficiency is low and the cost of detection is high. In order to reduce crosstalk between detectors, high-energy CT generally passes through a "tunnel-type" collimator to collimate the rays before the ray source enters the detector, because each detection unit needs to have a corresponding collimator However, objectively, the number of detectors per unit length is small, the cost of a single detector is high, and large-scale integration cannot be carried out. However, without increasing the detection density, in order to impro...

AI Technical Summary

Problems solved by technology

Generally speaking, the third-generation scanning method of CT has higher scanning efficiency than the second-generation scanning method, but because the detector needs to fully cover the measured object in the third-generation layout method, many detectors need to be arranged to detect large-sized workpieces. unit, which directly leads to an increase in equipment prices

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