Contrast examination belongs to a common medical diagnostic technique, which mainly refers to the use of a contrast agent that is higher or lower than the density of human soft tissues to perfuse the examination site. The contrast agent perfused tissues and organs have obvious density differences from the surrounding areas, so that local morphological and functional abnormalities can be displayed by the instrument. The contrast examination can enhance the effect of image contrast and increase the accuracy of imaging diagnosis, which is helpful for doctors to judge the degree of the patient’s condition and provide a basis for treatment. A wide range of imaging procedures are involved, including gastrointestinal imaging, hysterosalpingography, angiography, cardiography, urography, bronchography, and salivary gland imaging. Gastrointestinal imaging usually requires oral barium, while vascular-related imaging usually requires injection of the appropriate iodine-containing contrast agent. Since some people have certain adverse reactions to contrast agents, such as headache, nausea, vomiting, etc., it is recommended to consult with the relevant physician before the imaging examination to determine whether you have any allergic symptoms, and to drink more water after the examination to facilitate the excretion of contrast agents. In addition, because some patients have little understanding of contrast examination technology, they tend to have anxiety, nervousness and anxiety, which increases the difficulty of the examination and even makes it impossible to complete the examination successfully, so many contrast examination items have been replaced by CT and MRI, etc. Even with other technologies, imaging is still an important adjunctive test. Gastrointestinal angiography, hysterosalpingography, angiography, etc., are still common imaging modalities and widely accepted by patients as they have the advantages of safety, as well as high sensitivity and accuracy, and can help doctors clearly diagnose the size and nature of various lesions.