December 8, 2023

Medical Trend

Medical News and Medical Resources

Will a CT scan be harmful to the body and cause cancer?

Will a CT scan be harmful to the body and cause cancer?


Will a CT scan be harmful to the body and cause cancer?

How harmful is a CT scan to the body? Can it cause cancer? Do 4 points to reduce damage


“There is no radiation in the MRI, why did the doctor ask me to do a CT scan? What if the CT causes lung cancer?”

This is a very interesting question. MRI and CT are both important examination methods in hospitals.

The difference is that one has radiation and the other does not.

Why do doctors recommend using radiation CT for lungs Ministry inspection?


1. The MRI is clear and there is no radiation. Why do doctors recommend CT?

CT, or electronic computed tomography, is one of the modern imaging diagnostic methods.

The product of combining electronic technology, computer technology and X-ray imaging technology can be used for the examination of organs in any tissue part of the body.

CT equipment generally includes three parts: scanning part, image reconstruction system, image display and storage system.


CT imaging is a type of tomographic imaging, which is equivalent to dividing the human body into layers to observe lesions.

The X-ray beam is projected along a certain section of the human body from multiple directions, and the X-ray signals of the multi-row detectors with extremely high sensitivity are used to make the information provided in the display of diseases more abundant.


Many people wonder: MRI can also “image” the inside of the body, why is CT with radiation more recommended for lung examination?


In this regard, the expert explained that although MRI and CT belong to the same category of imaging, there are essential differences between the two.

Magnetic resonance imaging has high resolution on soft tissues such as blood vessels, nerves, muscles, ligaments and hyaline cartilage, while the lungs are mainly gas, and the magnetic resonance imaging effect is poor, which is more suitable for examination by CT.


Will a CT scan be harmful to the body and cause cancer?



2. There is radiation in lung CT, can it really cause lung cancer?

CT has always given the impression that the radiation is large and harmful to the body.

The American College of Radiology has conducted a comprehensive evaluation of the amount of radiation, whether CT radiation will cause cancer, and let’s see some details.


According to the test, the radiation dose of a lung CT is 1.5mSv , which is equivalent to the radiation dose we are exposed to in normal life for 6 months.

Let ‘s take a look at the radiation dose of chest CT, which is 7mSv , which is equivalent to our normal daily life exposure to radiation for 2 years.


Liu Biao, director of the testing center of Xinjiang Center for Disease Control and Prevention, said that the radiation dose level of CT varies with different types, but these are strictly regulated by the state.

The amount of radiation is not so terrible, and the body’s own repair ability can expel part of the radiation from the body .


A prospective, uncontrolled observational study in the United States showed that CT screening was also beneficial in reducing lung cancer mortality.

The study found that annual CT screening for 3 consecutive years reduced lung cancer mortality by 20% in smokers. It can be seen that for high-risk groups, it is still necessary or recommended to do it once.




3. Is it safe to do CT several times a year?

Some people’s misunderstandings about radiation lead to exaggerating their harm. In fact, people are exposed to radiation from nature all the time, such as solar energy, house materials, when flying in an airplane, and so on.


Director Liu Biao said that the annual dose of ionizing radiation absorbed by the human body is less than 100 millisieverts , which is in the safe range and will not cause obvious harm to the body.


Of course, although CT radiation is controlled under safe standards, it cannot be abused. Director Liu Biao suggested that patients should receive necessary examinations under the guidance of doctors.

Frequent unnecessary tests may absorb excess radiation, which can lead to disease. If it is not necessary for clinical diagnosis, it is best not to perform CT more than twice a year .

Children, pregnant women, and other people with high radiation sensitivity should try not to do or do these checks as little as possible.



4. How to reduce damage if doing CT?


Before the examination, do the following points, which can effectively avoid excessive absorption of radiation and cause harm to the body.


1) Follow the doctor’s orders

When performing a CT examination, you should obey the doctor’s orders. Don’t think that you can ignore the doctor’s orders if you know something about the CT examination.



2)Inform in detail

Before the examination, you must tell the doctor truthfully, and you have done several CT scans before to avoid repeated examinations in a short time.

Generally, an occasional CT does little harm to the body, but continuous CT examinations in a short period of time may cause residual radiation to affect the body.


3) Do not bring metal for inspection

Metal objects will interfere with the test results, so all metal objects must be removed before the test to avoid affecting the test results and causing harm to the body.


4) Block unnecessary parts

For parts that do not need to be examined, patients can choose some special radiation-proof coverings to cover, especially the thyroid and sexual organs that are more sensitive to radiation, which are more susceptible to CT damage.


The essence of CT examination is to allow doctors to better observe the lesions, distinguish the lesions, and formulate the most suitable individual treatment plan for the patient.

If it is because of rumors of radiation, the CT examination is avoided, and the final feedback is still on his own body.




(source:internet, reference only)

Disclaimer of

Important Note: The information provided is for informational purposes only and should not be considered as medical advice.