CT relies on radiographic imaging, ultrasound imaging through sound waves, CT and ultrasound in the diagnostic accuracy of different diseases have their own advantages, clinicians will be based on the needs of patients to select the appropriate examination. 1, CT full name of computerized X-ray tomography, according to the X-ray in different tissues of the human body through the rate and absorption of different, the application of extremely sensitive computer to receive signals to achieve the purpose of measurement of the human body, you can get extremely fine photographs to reflect the shape of the organs, tissues, organs within the body, and to find any part of the body of the small lesions. Therefore, it plays an important role in acute cerebral hemorrhage, cerebral infarction, bone fracture, joint lesions and tumors. 2, ultrasound is a kind of ultrasound examination, the use of sound waves on different texture objects produce different echoes, so as to produce different levels of images, used to reflect the morphology and structure of the internal organs. Although ultrasound is not as fine as CT, it is important for the early diagnosis of heart, liver, gastrointestinal and other diseases and its diagnosis of gallbladder-related diseases can be used as the gold standard, because of its non-radiation and no side effects, it has an indispensable position in the diagnosis of maternal and fetal. Warm reminder: all kinds of physical examination programs have their own targeted significance, in the need for examination when the doctor selects the examination suitable for the patient.