MRI and CT are two completely different scanning methods, as shown in the following aspects: First, the principle of the two is different. MRI uses magnetic fields, so there is no radiation to the human body, while CT uses radiation, so there is a certain amount of radiation to the human body. Second, the scan time is different, the price is different, MRI scan time is longer, the price is high, while CT scan time is short, the price is low. Although there are some overlaps in some parts of the body, CT is more effective for hemorrhagic brain diseases, lung diseases and fracture diseases. MRI is better for cerebral ischemic diseases, soft tissue, blood vessels, nerves, joints, cartilage, etc. Fourth, the examination has different requirements for patients and different contraindications.