Intravenous urography (IVP) is mainly used for urinary stones and urinary tuberculosis, etc. IVP is a common examination method in urology and gynecology, which is characterized by low pain and high diagnostic efficiency, especially for urinary stones and urinary excretory function, and has authoritative diagnostic value. After intravenous injection, almost all of the organic iodine solution is filtered through the glomerulus and enters the renal tubules, and finally discharges into the renal calyces and renal pelvis to make it visible. It can not only show the anatomical form of the renal calyces, renal pelvis, ureter and bladder lumen, but also understand the excretory function of the two kidneys. Unsuitable groups: 1. Patients with renal failure Because of the low concentration of contrast agent in the urine, poor visualization, and possible toxicity to the kidneys, resulting in deterioration of renal function, this test is not recommended for patients with renal failure. 2. Patients with positive iodine allergy Patients with positive iodine allergy or a history of previous iodine allergy should not undergo this test. Even if the iodine allergy test is negative, there is still a possibility of allergic reaction, and the patient should be closely observed during the imaging process. 3. Pregnant women In order to avoid the influence of X-rays on embryonic development, pregnant women need to be strictly controlled. For women of childbearing age, the imaging examination should be performed within 10 days after menstruation. 4.Multiple myeloma When patients with this disease do intravenous urography, urinary closure may occur, especially in patients with oliguria, so this examination should not be performed. 5, fever and serious liver, cardiovascular and cerebrovascular diseases The above conditions are contraindicated for this examination.