Truth of radiation during the radiology check

Sophe Dai, Ultrasound Physician

In the imaging examination items commonly used in clinical practice, ultrasound and MRI (nuclear magnetic resonance) have no radiation and are harmless to human body. As a result of ionization effect, X-ray and CT will produce certain radiation. Exceeding a certain dose can cause harm to human body. Some patients are reluctant to receive the radiographic examination even when they are sick due to the fear of radiation. In fact, this fear is unnecessary.

Fact 1:The normal radiation dose is not very high

When a routine chest X-ray is taken, only 0.12mSv is given to the lungs, as much as sitting in a plane, about 1/20000 of the single biggest acceptable dose which can cause human body damage. Our body would accept 1 mSv ~ 2 mSv X-ray radiation every year in the natural world. It can be seen that a normal X-ray examination does not cause harm to the human body, and there is no need to worry about it.

Fact 2:CT does have a biological effect on cells

Of course, the fearless attitude to radiation is also undesirable. CT is still an irreplaceable examination for its clear image, fast imaging speed and wide application. But if the examination is more frequent, CT does have a biological effect on human cells.

At present, multi-slice spiral CT (MSCT) can obtain higher quality images in a shorter period of time. As the scanning layer becomes thinner, the required radiation dose will inevitably increase. If the patient’s dose is not controlled, CT radiation dose will be the limiting factor for its wide application. Therefore, the staff of the radiology department has the responsibility to control the radiation dose and avoid the risk caused by the cumulative effect.

Fact 3: Low-dose CT is still safe

Although CT radiation hazard should not be ignored, conventional CT examination dosage is still very small in formal medical institutions. It won’t cause harm to human body in general. Moreover, with the continuous development of medical imaging technology, the radiation dose received by the public has been reduced by 1/2 compared with the past.

Fact 4: “Special groups” should avoid radiation as much as possible

Special groups mainly refer to children and pregnant women, including women who are preparing for pregnancy. Children are more sensitive to radiation, and the risk of ionizing radiation is higher than adults, especially when it comes to thyroid and gonadal tissues. For a fetus within one month, the effect of radiographic imaging drugs is generally “all” or “none”. That is, if the fetus is affected, the pregnant woman will definitely have a miscarriage. Otherwise, there would be no reaction. At the same time, X-rays can also affect the quality of male sperm, which may lead to an increase in the rate of sperm abnormalities. Therefore, if either of the couple has been exposed to x-rays, the pregnancy should be delayed by 3 to 6 months, and the physical factors of the man should not be ignored.

Fact 5:Anti-radiation foods can improve tolerance

Although CT has radiation risk, it is still a necessary and irreplaceable medical method. In order to improve the body’s tolerance to radiation, we can eat more food which is rich in essential fatty acids, vitamin A, K, E, and B vitamins, such as black fungus, black sesame seed, seaweed, kelp, tomatoes, garlic, green tea, etc.

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