1.Gastrointestinal barium contrast examination includes esophageal barium swallow, gastrointestinal barium meal, small intestinal barium enema and colon barium enema examination, and now the highest value is the gas-barium double contrast examination of the above parts. Indications for barium esophageal swallow: patients who suspect esophageal lesions due to dysphagia or painful swallowing and need further examination to confirm the diagnosis or exclude esophageal stenosis and obstruction; mediastinal masses that need to be known to be unrelated to the esophagus; and review of esophagus after surgery. Indications for gastrointestinal barium meal: suspected gastric and duodenal tumors, ulcers, inflammation, etc.; identification of the origin of abdominal masses; review after gastrointestinal surgery. Indications for barium enema of small intestine: suspected inflammation, tumor, vascular malformation, developmental malformation of small intestine, finding the cause of bleeding, etc., and those who fail to detect the lesions in routine gastrointestinal examination or are not sure about the nature of the lesions. Indications for colonic gas-barium double contrast: colonic tumor, colonic inflammation, congenital malformation of the colon, colonic obstruction and so on. Defecography and colon transportation test Defecography Barium sulfate suspension is injected through the anus to fill up the rectum. The subject is made to sit on a special toilet, and the direction of X-ray is parallel to the coronal plane of the human body. Let the subject do the simulated defecation action, take the side image of the rectum and anal canal of different phases of sitting still, lifting the anus, holding back strongly, and discharging forcefully, which is valuable for clarifying the etiology of constipation with outlet obstruction. Colonic transport test To make a better evaluation of the transport function of the colon. Oral granular marker 20, respectively, in 24 hours, 48 hours, 72 hours were taken lying down abdominal plain film, to understand the distribution of markers, colon transportation function should be more than 80% of the normal 72 hours should be discharged. If the colon has normal transportation function, more than 80% of the markers should be excreted in 72 hours. The markers will not be decomposed and absorbed by digestive juices, and the specific gravity is the same as that of feces. 3.Hysterosalpingography is an examination method that injects contrast agent through the cervical opening to show the inner cavity of uterus and fallopian tube. Specific operation is under fluoroscopy through the cervix intubation, injection of 40% iodized oil or water-soluble organic iodine preparation, filling the uterus and fallopian tube cavity, and need to be repeated at certain intervals to take pictures. On the one hand, the morphology of the uterus and fallopian tube and the patency of the fallopian tube can be observed, and on the other hand, the presence or absence of pelvic adhesion and the degree of adhesion can be inferred by observing the dispersion of the contrast agent in the pelvis, especially around the ovaries. Intravenous urography is a method of injecting organic iodine preparation into the venous blood vessels, reaching the renal artery through blood circulation, and concentrating the iodine preparation in the renal pelvis and calyces after glomerular filtration, so as to understand the morphology and structure of the renal pelvis and calyces, the ureter and the bladder, and the function of the kidneys in general. Indications: to understand the cause site of urinary tract obstruction; to understand the cause of hematuria; to understand whether urinary tract irritation is caused by tuberculosis or pyelonephritis; to understand whether renal colic is caused by negative stones or the degree of fluid accumulation caused by stones; to understand the renal function in case of severe fluid accumulation or renal hypertension. 5.Retrograde urethrography The method of inserting a catheter into the ureter or renal pelvis under cystoscopy and injecting contrast medium to show the morphology of the renal pelvis and ureter, the cause of obstruction and stenosis, as well as the location and degree of obstruction. 6.Cholangiography is divided into oral cholangiography, intravenous cholangiography, trans-“T”-drainage tube cholangiography and retrograde cholangiopancreatography through fiberoptic duodenoscope and other different ways. The main purpose is to check whether there are stones, tumors and stenosis in the bile duct, and to understand the cause, location and degree of biliary obstruction and dilatation. 7, body photography The basic principle is that when X-ray exposure X-ray tube and film along a branch point to the opposite direction of the movement, the level of the lesion to be examined is located in the moving line of the central axis point. This method can clearly show the image of the plane of the fulcrum, so that the other levels of the image blurred. Body radiography is used to visualize bronchial and intrapulmonary lesions, or lesions in overlapping areas of other organs. Because of its poor image density resolution, with the popularization of multilayer spiral CT and the progress of post-processing technology, body layer photography is basically replaced by CT. 8. Vertebral canalography and arthrography The contrast agent is injected into the subarachnoid space of the spine through lumbar puncture, and the flow of the contrast agent in the subarachnoid space of the vertebral canal is observed by fluoroscopy and radiography, so as to diagnose the location and cause of the space-occupying lesions in the vertebral canal, as well as the location and degree of the obstruction of the vertebral canal. Arthrography involves percutaneous puncture of the joint cavity under X-ray and injection of contrast material to form an artificial contrast to facilitate observation of the structures in the joint cavity, including changes in the articular cartilage disk, synovium, joint capsule and intra-articular ligaments. Since the above examination is invasive, it is basically replaced by magnetic resonance imaging. Bronchography is a method to visualize the bronchial tubes by injecting a contrast agent into the bronchial tubes. The common contrast agent is 40% iodized oil with appropriate amount of sulfonamide powder, and organic iodine contrast agent can also be used, which is mainly used for checking bronchial dilatation and benign and malignant tumors of bronchial tubes. Due to the emergence of fiberoptic bronchoscopy and multi-row spiral CT, it basically replaces this examination technique. 10.Salivary gland imaging The salivary gland is intubated through the mouth of the salivary gland, and the contrast agent is injected to observe the cause of salivary gland enlargement and abnormal salivary gland secretion.