CT and MRI are two completely different imaging methods, the main differences are as follows: 1. The imaging principle of the two is different, CT uses radiation for tomography of various parts of the body, so it has a certain degree of radiation, while MRI uses hydrogen atoms moving under the action of an applied magnetic field for imaging, so it has no radiation on the human body. 2. CT is mainly used for examination of head, chest, abdomen, bones and other organs, and is mostly used for emergency treatment, while MRI is mainly used for head, breast and soft tissues. 3, the price of the two is different, CT is relatively cheap, usually around 200 yuan, while MRI is relatively high, usually around 500 yuan.