X-ray radiation is usually not very large and patients do not need to worry about it, because studies have shown that the radiation exposure of X-ray patients is usually 0.023 mSv/sec, and its cancer rate is quite low, even minimal, so patients do not need to worry about it and refuse X-ray examinations. CT radiation is far more than that of X-ray, and its radiation unit is usually about eight times that of X-ray, so relatively speaking, its radiation damage is heavier and the chance of causing cancer is relatively higher.