Nephrography can be divided into intravenous urography and nephrography of the arteries. Intravenous urography requires the injection of a contrast agent into a vein, which is filtered through the bloodstream and passes through the kidneys without being absorbed by the kidneys and excreted from the body in its original form. In this process, X-rays are used to monitor the absorption, metabolism and excretion process of the organs by the kidneys, to find out whether there is fluid accumulation in the kidneys and to determine the degree of fluid accumulation in the kidneys, whether there is a filling defect in the renal pelvis, whether there is a filling defect in the ureter, whether the ureter is patent, whether there is any obstructive or occupying disease, etc., and to determine whether there is any disease such as tumors in the renal pelvis. Arteriography of the kidneys is an invasive imaging procedure that requires arterial puncture, placing an imaging tube into the renal artery, and then injecting a contrast medium at high pressure to learn about the distribution of the blood supply to the kidneys. It is often used in trauma to the kidney to determine which blood vessel is bleeding and can be used to seal the vessel under imaging. It can also be applied to renal tumors for arterial perfusion chemotherapy, using contrast to understand the location and blood supply of the tumor, and pumping chemotherapy drugs into the blood supply of the tumor to cure the tumor. It can also be used to know whether there are malformations of renal blood vessels. For some unexplained hematuria, considering the bleeding caused by malformations of renal blood vessels, renal arteriography can be carried out to confirm the diagnosis.