What is spiral CT?

Spiral CT uses slip ring technology to synchronize the rotation of scanner with the movement of scanning table. When the X-ray tube rotates continuously around the patient's body, the examination table moves smoothly in the scanning frame, and the movement track of the tube is spiral, so it is named spiral CT. The sampling method of spiral CT is volume scanning, so it can collect three-dimensional information of the detected part and reconstruct multiple cross-sectional images of human body. Compared with previous CT, spiral CT has the following outstanding advantages: ① The scanning speed is fast, and the patient can complete the whole scan in one breath. ② There is a large amount of information in the image, and three-dimensional reconstruction, surface reconstruction and CT endoscopy can be carried out on this basis. (3) The image resolution is high, and it can be reconstructed by CT with arbitrary slice and thickness. ④ Combined with contrast examination, we can not only know the ct manifestations of the examined parts at different times, but also perform morphological and functional examinations such as CT angiography and CT perfusion imaging.