In renal insufficiency, contrast examinations are not recommended. Contrast agents are used in contrast examinations, which are divided into ionic and nonionic contrast agents. Clinically, non-ionic contrast agents are commonly used, mainly iohexol, iodixanol, etc. They have low permeability, even close to plasma, relatively small toxic side effects, high biosafety, low neurotoxicity, well tolerated by the body, and small chance of allergic reactions, and can be used for various angiography and transvascular contrast examinations, but most of the contrast agents are excreted by the kidneys, and when renal insufficiency, it will aggravate The damage of renal function. If the patient’s condition is serious and potentially life-threatening, when contrast examination is necessary, it can be performed under the guidance of a physician. Patients should be fully informed before the operation, sign an informed consent, pay attention to adequate hydration before and after the operation, and pay attention to timely monitoring of renal function.