When is an intravenous pyelogram necessary? Intravenous pyelogram is a common technique for clinical diagnosis. High doses of intravenous urographic contrast can clearly show the anatomical pattern of the renal pelvis and calyces. An iodine allergy test must be performed before imaging. (1) Urinary tract disorders with abnormal changes in clinical or laboratory tests and the need for imaging for a definitive diagnosis are optional. For example, patients with suspected pyelonephritis and polycystic kidney. (2) All abdominal or retroperitoneal tumors have indications for intravenous urography. (3) Certain diseases with urological lesions, such as gout, diabetes, hypercalcemia, pelvic disorders, Hodgkin’s disease, lymphosarcoma and other diseases, may be examined. (4) Certain clinical manifestations, suspected from urological diseases, such as hypertension, anemia, unexplained fever, etc. (5) If urinary stones are suspected, but there is no positive finding on abdominal plain film, contrast examination can be performed. What are the contraindications to intravenous pyelogram? (1) Renal failure: This test is contraindicated in 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. (2) Iodine allergy: Patients who are allergic to iodine should apply desensitizing drugs before imaging. If the iodine allergy test is negative, there is still a possibility of allergic reaction and close observation is required during the imaging procedure. (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 intravenous urography is performed in patients with this disease, urinary closure may occur, especially in patients with oliguria, so this examination should not be performed. Preparation for urography Generally, three days before the imaging, you should abstain from gas-producing foods, such as milk, soy products, pasta, sugar, etc. The night before the imaging, cite the laxative prescribed by the doctor – senna leaves as if it were a tea, preferably with several cups, and have the stool expelled at any time. Its purpose is to expel the residue from the intestine and cleanse the intestine. An iodine allergy test should also be done before the examination. Drinking water is prohibited for 12 hours before imaging, and no breakfast is allowed that morning, while the breakfast mentioned here is dripping water. Gas in the intestine is mainly swallowed, and swallowing things and talking can cause gas to enter the intestine. Therefore, it is important to talk less and walk more to facilitate the expulsion of gas. Before imaging, you need to urinate and defecate to make the intestine and bladder empty. Procedure: I. The doctor will inform the patient of the indications and risks of intravenous pyelography (IVP), especially the need for the patient to have this test and sign it, and inform the radiology department of the appointment time. The patient will be prepared for bowel cleansing the night before, and the first iodine allergy test will be done if ionized contrast is used. Third, go to the radiology department on the same day to observe the effect of bowel preparation under fluoroscopy, if not, a cleansing enema is needed, and if feasible, you are ready to start. Some hospitals require another iodine allergy test before the official start. Of course, the radiology department must also sign a consent form. Fourthly, take a conventional supine abdominal plain film (KUB), prepare the abdominal compression belt, inject 20ml of contrast agent intravenously (76 compound pantopamine, the maximum dose should not exceed 40ml, nowadays, we usually choose non-ionic contrast agent iodophoresis), pressurize the abdomen at the same time (the specific pressure varies from person to person), keep the intravenous access after the injection and start the timing (the intravenous access is kept in case of an allergic reaction, so that we can provide first aid). Take pictures at 15, 25 and 35 minutes respectively, paying special attention to the kidney area, and take KUB again immediately after decompression. V. Ask the patient to drink more water. The harm of intravenous pyelogram is mainly due to X-ray radiation and nephrotoxicity of the contrast agent, but the harm of X-ray is insignificant compared with the significance of the examination.