CT and MRI are two different examination methods with different focus on diseases. MRI examination has no radiation, so fetus can undergo MRI examination, while CT examination has a certain radiation dose, and fetus absolutely cannot undergo CT examination. CT for general lung diseases is clearer and more accurate than MRI, while MRI is better than CT for soft tissue diseases, orthopedic diseases, joint cavity diseases, and neurological diseases, such as brain hemorrhage, early brain infarction, and cerebrovascular abnormalities, etc. For neurological diseases, MRI is better than CT. Therefore, for different diseases and different examination sites, the necessary examinations should be performed in conjunction with the clinician’s billing.