CT examinations are divided into general CT and enhanced CT, which play an important role in diagnosing diseases and observing their development. CT examinations are of high value in the diagnosis of head and neck diseases, chest diseases, central nervous system diseases, abdominal and pelvic diseases, as well as heart and large blood vessel diseases. There will be some rays during the examination, but these rays are very small and the radiation is not enough to cause great harm to the body, so there is no need to panic too much when doing this examination and just relax. However, the contrast agent is usually injected intravenously before the enhanced CT examination, and people who are prone to allergies should be aware that it may cause rash, facial flushing, rapid breathing and other allergic symptoms. For children and elderly people older than 60 years old, a doctor needs to assess the patient’s physical condition before doing CT to prevent any impact on health. This test is not recommended for women during pregnancy because radiation may cause fetal growth and development to be affected.