X-ray is the most basic radiological imaging measure, it is through the body’s different absorption of X-ray to distinguish different densities, bone is high density, appearing as white, fat and water is low density, appearing as black. CT imaging is a further upgrade based on X-ray, which can do tomography, with horizontal sections, so that each organ of the patient, at each level, can be detected. It can clearly determine the location and size of the lesion, and further enhancements can be made to determine the nature of the lesion. MRI is fundamentally different from X-ray and CT because it uses magnetic fields to image. The patient’s body cells contain positive and negative ions, which create a weak magnetic field. The magnetic field of MRI will be arranged differently, and different signals will be displayed. Magnetic resonance is not called high density and low density, but low signal or high signal. For ischemic lesions, it shows better than CT, while hemorrhagic lesions are inferior to CT. For relatively small tumors or other diseases, the positive rate of magnetic resonance findings will be higher, and magnetic resonance has no radiation and is less damaging to the body.