The radiation dose varies according to the different scanning sites, the size of the scanning range, and the exposure time. According to the scanning site, scope and time, the dose is calculated as follows: 1, the average dose of the head is 2mSv, which is equal to about 100 chest films; 2, the average dose of the neck is about 3mSv, which is equal to 150 chest films; 3, the average dose of the chest is about 7mSv, which is equal to 350 chest films; 4, the average dose of the abdomen is about 8mSv, which is equal to 400 chest films; 5, the average dose of the pelvis The average dose of pelvis is around 6mSv, which is equivalent to 300 chest films; 6. The average dose of liver three-phase dynamic enhancement scan is around 15mSv, which is equivalent to 750 chest films; 7. The average dose of spine scan is around 6mSv, which is equivalent to 300 chest films; 8. The average dose of coronary CT base is around 16mSv, which is equivalent to 800 chest films.