Introduction: CT is a very advanced medical imaging technology today. CT test is mainly used to help clinicians find out the causes of the disease. For example, cerebrovascular diseases, brain CT can be performed to determine whether there is infarction or bleeding in the brain.
CT can also check whether there are foreign objects in the bronchial and trachea. CT can be divided into many types. For different CT, the purpose is different. Patients need to make choices based on their actual situation and under the guidance of a doctor.
When performing CT tests, some people say that CT tests will have a great impact on the body, because CT tests usually have radiation, and the content of these radiation is very high. Some people even think that CT tests can cause cancer.
Although doctors repeatedly explained that routine CT tests have little impact on health, many patients still do not want to be exposed to CT. After all, no one wants their physical health to be affected.
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First, what is CT?
CT is the abbreviation of Computed Tomography, which is translated into Chinese, meaning computed tomography.
CT has two structural principles: first, it is the physical principle, that is, the characteristics of using X-rays are used to produce different attenuation ray projections of human tissues and organs.
and the other is the mathematical principle, that is, any object can be reproduced from its countless projections. According to these two principles, the CT machine should have an X-ray generation system, a signal reception system and an electronic computer processing system.
Its core equipment is X-ray bulb tube and high-voltage generator (X-ray generation), detectors (signal reception), electronic computers (signal processing and image reconstruction), and auxiliary equipment (monitors, cameras, etc.).
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1 CT scan, how much harm will it cause to the human body? Finally, a doctor is willing to stand up and explain the truth
In fact, as long as CT is not excessive, you don’t have to be overly nervous. The harm of CT mainly comes from ionizing radiation generated by X-rays. Ionizing radiation can destroy some macromolecular structures in the body, damage cells, and thus damage the human body.
In our daily life, we can be exposed to ionizing radiation anywhere, such as aircraft, safety scanning, background radiation.
According to the "Reference Level of Adult Diagnosis in X-ray Computed Tomography" issued by the state, the radiation received by various parts of the human body during the CT examination is:
China's radiation protection standards stipulate that the annual dose limit for radiation workers is 50mSv; the average annual upper limit for receiving radiation within 5 years is 20mSv, which means that the total radiation received will be safe if it is controlled within the safety value.
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So, what is the probability of cancer after CT examination?
was analyzed from animal experiments. Unless long-term and large doses of radiation can cause cancer, the possibility of cancer and myelosuppression is very low, so occasional CT scans do not need to worry too much about the damage to the body by radiation.
Although it is impossible to completely avoid radiation, there are ways to reduce radiation exposure, such as removing metal objects close to the body and preparing before checking.
For example, it is recommended to drink more water during a stomach scan, fill your stomach and work with a doctor. These methods can effectively avoid the adverse effects of certain tests and can also shorten the examination time.
CT is essentially an X-ray machine , which has higher requirements for radiation protection. Unless there are special needs, repeated unnecessary reviews are not allowed.
In general, only multiple CT scans within a short period of time will increase the risk of cancer. As for how many CT scans will cause cancer, there is no standard answer yet.
Due to different parts of the physical examination, the amount of radiation received is also different, so it may take dozens or even hundreds of times to develop into cancer.
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Remind everyone: 4 types of people are not suitable for CT
1. Baby
Generally speaking, babies under one year old cannot undergo CT examinations, because children at this stage are in the growth and development stage of the body. If CT examinations are performed, it is easy to cause X-rays to enter the body and affect the organs. When the baby's organs absorb X-ray radiation, it is easy to cause developmental problems.
2, heart disease patients
Patients with heart disease such as arrhythmia and coronary heart disease cannot undergo CT examination because there are certain risks during the CT examination. If it is not taken seriously, it is easy to cause harm after the examination, which will cause radiation from the CT examination to affect the heart's condition.
3. Allergic
Allergic people must pay attention in their daily life. They should not take some drugs or undergo some examinations casually. They should pay attention to it during CT examinations, especially to enhance CT, which requires the use of contrast agents during the enhancement process, which will cause allergies after entering the body.
4. Patients with renal insufficiency
People with renal insufficiency are prone to produce some toxins in the body due to poor excretion ability. People of this type should pay attention to it. They should not undergo CT examinations in normal times, because the radiation absorbed by CT examination is not easy to be discharged from the body, or when performing enhanced CT examinations, imaging agents will increase the burden on the kidneys.
