MRI and CT have their own advantages, MRI has high resolution for soft tissue and CT has high resolution for tissue density. In the clinical examination of the main nuclear magnetic resonance examination, is the use of a strong magnetic field so that hydrogen ions in the pulse effect of magnetic resonance phenomenon carried out by the imaging technology, the advantages of this examination is no radiation, will not cause damage to the human body, mainly on the soft tissue of the higher resolution, can be used as a central nervous system and joints within the lesions of the examination. CT examination in the clinical use of X-ray tomography to show small foci and microstructure and reconstruction of imaging, CT examination has a certain degree of ionizing radiation, will cause radiation damage to the human body, CT has a higher density resolution, in the density resolution of CT has a higher advantage, such as for the resolution of bone fracture, cerebral hemorrhage and so on is more convenient. Therefore, MRI and CT have their own advantages and disadvantages, according to the nature of the disease to choose a different examination method.