X-ray examination is a common clinical examination method, which has the advantages of simplicity, effectiveness and economy and is widely used in clinical practice. Its indications are as follows: 1. chest X-ray examination: mainly used to check lung inflammation, tumor and chest trauma, etc.; 2. urinary system X-ray examination: in addition to ultrasound, X-ray examination is a common examination method in urology, mainly used to check urinary stones; 3. bone and joint X-ray examination: mainly used to check bone and joint degenerative disease, fracture, dislocation, etc.; 4. X-ray imaging examination: including digestive tract Barium meal, intravenous pyelogram, hysterosalpingogram, vasectomy, etc.