(1) X-ray examination of the kidney: ① Urograms: should include the kidney, ureter and bladder, routine orthopantomogram can be performed, if necessary, frontal and lateral films are needed to distinguish gallstones from kidney stones, and should be prepared to clean the intestinal contents before examination. ② excretory urography: in addition to bowel preparation, fasting and abstaining from water 12 hours before routine dose imaging (except for young children and those with renal failure). Direct urography: retrograde pyelogram: direct injection of contrast, which can clearly show the renal pelvis and calyces and is not limited by renal function; percutaneous perforated pyelogram: its application has been gradually promoted in recent years, and is suitable for those with bladder twisting, urethral stricture, and children who are not suitable for retrograde imaging; excretory cystourethrography: only 100~200ml is needed for ordinary cystogram, and it is necessary to increase the amount of contrast agent when performing this examination After extubation, the patient should be instructed to urinate and take a whole urinary tract film at the same time. ④ Renal angiography: abdominal aortogram and renal arteriogram. In selective renal arteriography, a catheter with a bendable tip is inserted into the renal artery and contrast is injected to visualize the renal artery. (2) CT examination of kidney: CT examination can directly display the tomographic image of kidney with high resolution of soft tissue, clear image, and clear anatomical relationship, and the detection rate and correct diagnosis rate of disease are higher than ordinary X-ray examination. (3) Ultrasound examination of kidney: Ultrasound examination can show the location, size, morphology and internal structure of the kidney, and can observe various lesions in and around the kidney, especially ultrasound examination is painless and non-invasive, and is not affected by kidney function, rapid and reproducible, which is a more ideal examination method. (4) MRI examination of kidney: it can show multi-level images of kidney, i.e., transverse, sagittal or coronal cross-sectional images, etc., which can show the structure of kidney more clearly, especially for the diagnosis of renal parenchymal lesions can further improve the accuracy of imaging examination.