Radiation dose from X-ray: 0.2mSv. Radiation dose from chest X-ray: 1.1mSv. Radiation dose from CT: 2-15mSv: Head 2mSv; Chest 8mSv; Abdomen 10mSv. Radiation dose from angiography: 15mSv. There is no radiation from magnetic **** vibration or ultrasound! For the general population, the normal annual background radiation intake due to the environment for the average person is 1 to 2mSv per year. Radiation-related workers have a maximum radiation dose of 5mSv per year, and also need regular checkups.
CT, that is, computed tomography, which is the use of accurate collimated X-ray beams, γ-rays, ultrasound, etc., with a very sensitive detector around a part of the human body for a cross-section of one after another scanning, with a fast scanning time, image clarity and other characteristics, can be used for a variety of diseases; according to the use of the ray can be divided into: X-ray CT (X-CT) and γ-ray CT (γ-CT) and so on.
CT's working procedure is like this: it is based on the different tissues of the human body on the X-ray absorption and transmission rate of different, the application of highly sensitive instruments on the human body for measurement, and then the measurement of the data obtained by inputting electronic computers, electronic computers to process the data, can be taken down the human body to be examined by the part of the cross-section or three-dimensional image, to find the body of any part of the small lesions.
Reference:Baidu Encyclopedia-CT