An “upper urinary tract exam” is a test your doctor performs on your kidneys and ureters. The innermost layer of the bladder is the uroepithelium, which extends to the inner surface of the kidneys and ureters, so the latter two may also develop uroepithelial cancer at the same time. You may receive different tests depending on your doctor’s habits and the programs the hospital conducts. Patients with bladder cancer need to have this test regularly after surgery, even if their preoperative upper urinary tract test results are negative. Patients with low-grade tumors of the bladder have a low risk of also having upper urinary tract tumors (about 2%), while with high-grade tumors and diffuse carcinoma in situ, patients have up to a 40% chance of having upper urinary tract tumors. What are the means of upper urinary tract screening? Ultrasound is the simplest and most economical means of examination and is often the first choice. Ultrasound technology generates sound waves that detect the echoes of internal structures of the organs and form a sonogram. Ultrasound can be used in obstetrics to observe the fetus. Because of the absence of radiation, ultrasound is excellent for detecting tumors and stones inside the kidneys, as well as hydronephrosis due to ureteral obstruction, but it is not useful for smaller tumors in the renal pelvis or ureter, and other tests are needed to assist. An intravenous pyelogram (IVP) is an X-ray test that shows the general outline of the kidney and shows the details of the collecting system more clearly than ultrasound. The X-ray contrast is injected through an IV, filtered and concentrated through the kidneys, and the images are taken on X-ray a few minutes after the injection. A small tumor or stone in the collecting system shows up as a filling defect on the image. IVP can be used quite safely in every patient unless renal function has been severely impaired or there is an allergy to the contrast agent. the quality of the IVP shot is closely related to the bowel preparation, and gas-producing foods such as milk, soy products, pasta, and sugar should generally be abstained from three days prior to the imaging. Laxatives need to be taken the night before the imaging, the purpose of which 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 the imaging, and no breakfast is allowed on the morning of the same day, 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. Urination and defecation are required before imaging to make the intestine and bladder empty. CT can use X-rays to show the details of internal organs. The scanner receives a large number of x-ray signals at one time, which are then synthesized into one image by a computer. When examining the kidneys, two scans are usually required. Once without contrast, the kidney can be detected for stones. The second time with contrast, it can detect tumors in the kidney or collecting system, and the images are much clearer than IVP. It can also look at the abdomen, other organs in the pelvis and lymph nodes to help with clinical staging and to rule out any co-morbidities. Patients with medical conditions in the kidneys or patients with allergies to contrast are better off undergoing tests that do not require contrast, such as MRI or retrograde pyelogram. MRI (magnetic resonance imaging) uses magnets to align molecules in the body, and when the magnets are turned off, the molecules in the body revert to their normal state of random orientation. As they revert, weak electrical signals are generated that are detected by the MRI machine, and these signals are then processed into very fine images. MRI has advantages over CT in some cases, but MRI is more expensive and some hospitals do not have MRI equipment, so it is not a routine test of the upper urinary tract. Patients with surgical implants, such as cerebral angioma clips, cochlear implants, and insulin pumps, are not good candidates for MRI. the main advantage of MRI is that it can be used in patients with kidney disease or allergies to contrast media. Retrograde pyelogram is a procedure in which the urologist performs a cystoscopy by extending a catheter into the ureter, injecting contrast through the catheter to fill up the ureter and renal pelvis, and then taking X-rays, which gives a good picture of the entire upper urinary tract. This test does not require intravenous contrast, so it can also be used for patients who are allergic to contrast or have kidney disease that prevents them from undergoing intravenous imaging. However, retrograde pyelogram requires some special equipment that is not needed for other tests. Therefore, it is often used in patients who are unable to undergo intravenous pyelography or who have unclear contrast findings, or who have had abnormal findings on a previous exam. Ureteroscopy provides the most definitive examination. Much like a cystoscope, but with a smaller lens, it is typically performed in the operating room. Careful insertion of the ureteroscope into the ureter enables the urologist to clearly visualize the interior of the ureter and follow the ureteral lumen all the way up into the kidney. Similar to a cystoscope, there are hard and soft ureteroscopes. A soft ureteroscope allows visualization of almost all corners within the pelvic calyx collecting system. For suspicious areas, a biopsy can also be performed for analysis and testing by a pathologist. Ureteroscopy provides the best view of the collecting system, but requires anesthesia for the procedure and has the potential to damage the kidneys and ureters; therefore, it is only used in patients with existing abnormalities in the upper urinary tract examination that require further management.