The accuracy of MRI in determining some tumors, such as cavernous hemangiomas, malignant tumors, and uterine fibroids, can reach 100%. However, the accuracy of MRI will be affected if some tumors may have atypical presentation or wrong examination method. For example, the doctor only sees thickening of the stomach wall, but there are many reasons for thickening of the stomach wall, such as inflammation, tumor, esophageal varices, etc. However, if the patient does enhancement, especially doing MRI T2-weighted image and diffusion-weighted image, the diffusion limitation of tumor gastric wall thickening can be seen, i.e. leather stomach. At this time, it is easier to make the diagnosis of gastric cancer or gastric lymphoma. If the patient does not have an enhancement examination and simply sees thickening, an accurate diagnosis cannot be made. In contrast, pulmonary ground glass nodules may be infiltrative lung cancer. If it is infiltrative lung cancer, CT examination can clearly diagnose it, but MRI cannot diagnose it.