Nephrography is generally used to find out whether the patient has organic lesions of the urinary tract, whether the ureter is patent or not, whether there is renal tuberculosis and renal tumors, as well as to find out the excretory function of the kidneys. Nephrography, also known as intravenous pyelography, refers to the intravenous injection of contrast medium, which is excreted into the urinary tract through the kidneys to observe the whole urinary tract lesions, and it can indirectly understand the filtration function and concentration function of the kidneys. 1. Organic lesions: usually include ureteral, bladder and renal lesions, and filling defects can be observed after the passage of contrast medium. 2. Whether the ureter is patent or not: nephrography can be used to find out the patency of the ureter, i.e. whether there is any obstruction, and to determine whether there are tumors or stones. 3. Whether there are renal tuberculosis and renal tumors: the destruction of renal pelvis and renal calyces caused by renal tuberculosis, chronic pyelonephritis and renal pelvis tumors also have their characteristic changes. 4. Renal excretory function: intravenous pyelogram can not only find out the abnormality of the urinary tract, but also effectively determine the excretory function of the kidneys. Please go to regular hospitals and follow the doctor’s instruction to have intravenous pyelogram, so as not to affect the diagnosis and treatment.