The differences between spiral CT and ordinary CT are as follows: 1. The power supply method of spiral CT adopts slip ring technology, while the power supply method of ordinary CT is traditional cable power supply; 2. The scanning method of ordinary CT is reciprocal rotation, while the scanning method of spiral CT is continuous rotation in one direction, while the subject moves continuously and uniformly in one direction through the scanner; 3. The image reconstruction algorithm is also different between conventional CT and spiral CT. The normal CT scanning frame rotates for one week and the data collected is the projection data of a certain tomography in all directions. Spiral CT, on the other hand, acquires scan data during the process of continuous movement of the subject, and each time the data is acquired from a different plane; 4. Spiral CT scans faster than ordinary CT, with significantly higher clarity than ordinary CT, and can detect substantial lesions of 2mm or more, while spiral CT can understand the size, shape, and characteristics of lesions in three dimensions, greatly improving the probability of disease diagnosis. The radiation dose of spiral CT is also relatively low, which greatly reduces the possibility of radiation hazards to patients during the examination.