Having a CT is something that all of us have probably experienced, and even if you haven't had a CT, you may have to use it at a later date. advances in CT technology have indeed made a great contribution to human health, but you may have also heard the claim that CT causes cancer. So is this claim right or wrong?

First of all, Dr. Zhang also believes that CT has irreplaceable advantages in diagnosing diseases. If it is medically necessary, I think you should do it with confidence, and you generally will not develop cancer just because you have a CT. But if it's not medically necessary, don't do it. After all, the ionizing radiation brought by CT does have the risk of increasing the incidence of tumors. Here's what Dr. Zhang has to say about CT causing cancer.

1、Why is it said that CT may cause cancer?

A search of the literature reveals that there are indeed some overseas studies on the carcinogenicity of CT, and that the ionizing radiation released by CT may induce unstable changes in certain genomes of the body, and such a possibility does exist. Such destabilizing changes may be passed on to replicating offspring and may be passed on from one generation to the next. Thus, even when no genetic changes have occurred in the irradiated cells themselves, the irradiation has placed the cells in a critical state where they may become cancerous, and in this way the frequency of tumor mutations in the offspring cells is increased. Such changes may increase the incidence of tumors.

2、Why is it only said that CT causes cancer, but no one says that X-ray examination causes cancer?

Because the radiation dose from a CT is hundreds of times greater than that from an X-ray, the ionizing radiation dose from a single X-ray is not elevated enough to cause cancer. However, the ionizing radiation of CT examination is far greater than that of X-ray examination. Therefore, it can be said that the vast majority of ionizing radiation in the field of diagnostic imaging is generated by CT. Foreign studies show that if the radiation dose to the public increases by 1000mSv, the incidence of cancer will increase by 4.1%.

3. What do foreign studies think?

Some experts of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) have argued that 0.6% of the cumulative cancer risk for people over 75 years of age in the United Kingdom is attributable to diagnostic radiation, which is mainly due to CT examinations. In the United Kingdom, the United States and the Netherlands, where the use of CT is the lowest, the amount of diagnostic radiation is also the lowest, so the cumulative incidence of cancer caused by diagnostic radiation is lower, and studies have shown that only about 0.4% of cancer patients can be attributed to diagnostic radiation. Japan, a country that uses more CT examinations and has three times the amount of diagnostic radiation than the United Kingdom and the United States, also has a much higher incidence of radiation-induced cancer than the above countries, at about 3.2%.

4. Is it true that the better the CT, the higher the radiation dose?

With the gradual popularization of 64-slice spiral CT and even higher level CT, the thickness of the examination layer is getting thinner and thinner, the image is getting clearer and clearer, and more and more items can be checked, which is a good thing. However, this is accompanied by a higher and higher dose of radiation received by the examinee.

The above is some related knowledge that Dr. Zhang reviewed the literature and compiled, or suggested that we should do CT when it must be done, and there is no need to take CT for routine checkups when it should not be done. Doing a CT is not carcinogenic, but it is not necessary to do CT can not do, after all, do more CT may increase the risk of tumors.

Many of us have gone to the hospital for a CT scan at one time or another, but at the same time, we know that CT scanning is radioactive to the human body, and we have heard that there is a risk of cancer. However, sometimes this CT examination is one of the programs that must be done in order to diagnose and treat the course of the disease. Therefore, many people want to know, in the end to do a CT examination will produce how much radiation on the human body, on the human body is the probability of cancer? Below I will take you to understand whether this CT examination will have the risk of causing cancer and how we should discharge the radiation in the body.

I. Hazards of CT radiation on the human body

A CT examination done in a hospital is a multi-row spiral CT examination, which uses X-ray source imaging to scan the body's organs and tissues, which means that the area to be examined is divided into countless tiny squares with a volume of less than one cubic millimeter, and the images are composed afterwards. This makes it possible to see more closely and accurately, and to detect even the smallest lesions in the organs and tissues. However, in this process, the body is exposed to ionizing radiation from X-rays, which is also a hazard of CT.

This harm in the final analysis is that it can cause direct damage to the DNA of human cells, such as destroying the structure of certain macromolecules in the organism, causing protein molecular chain breakage, RNA or DNA breakage, destroying some enzymes important to the metabolism of substances, etc., or even directly damage the cellular structure, and finally may lead to genetic mutation or chromosomal translocation aberrations, thus causing cancer.

Second, how much radiation will you get from a CT scan?

As we have said above, a CT examination is radioactive to the human body, but is the radiation dose of a CT examination within the tolerance range of our body? Is there any risk of cancer? As the saying goes, "It's a joke to talk about toxicity regardless of the dose", let's take a look at some data first.

It has been said on the Internet that the dose of X-rays received by the human body during a CT examination is 5 to 10 times that of an X-ray examination. There is also a claim that a CT scan is equivalent to 400 X-ray examinations. Are these claims true?

I have looked at some data to get some results and we can look at the two charts above, the radiation dose table for a general X-ray and the radiation dose table for a routine CT examination. As we can see from the charts, the average radiation dose received by each part of the body is different. Especially CT examination, it can be done due to the different parts of the radiation dose level is not the same, but in general are higher than 1mSv, such as head CT is about 2mSv, chest CT is 7mSv, and some parts of the body can even reach more than a dozen mSv. So that is to say, the radiation dose of CT is dozens of times or even hundreds of times of the chest radiographs. Let's take chest CT as an example, the radiation of chest ordinary CT examination is almost 7mSv, and the radiation dose of chest low-dose CT examination is also 0.2-0.5mSv, while the radiation dose of chest X-ray is 0.02mSv. that meansA low-dose CT exam is almost the dose of 10 chest x-rays, while a regular CT exam of the chest is about 350 chest x-rays. This shows that all those statements above are true.

Since a CT exam has so much more radiation dose than a chest X-ray, does that mean that every CT exam is very harmful to the human body?

Of course not.Some data show that the annual radiation dose of a person does not exceed 100mSv are relatively safe range, and we often don't reach such high radiation levels with a CT scan.

Third, what is the probability that a CT will cause cancer in humans?

Since the radiation dose of each CT examination is within the safe range, does it mean that we can have a CT examination with no worries? This is not the case either! There is still a cancer risk associated with CT examinations.

Adult abdominal CT examinations with an effective dose of 10 mSv increase the risk of cancer by 1/2000, according to the study.The International Commission on Radiological Protection (I-CRP) has also conducted studies abroad. In addition, there is also research data from abroad showing that the International Commission on Radiological Protection (I-CRP) study confirms that a CT whole-body scanning medical examination.Increases the risk of radiation-induced cancer by about 8%, and the higher the exposure, the greater the likelihood of fatal cancers and hereditary disorders.。

And British researchers have published a study in The Lancet, which claims that X-rays, which are commonly used in hospitals to diagnose illnesses, and CT scans, which are becoming more common, may be the cause of cancer in some people. X-rays are responsible for 0.6% of all cancers diagnosed each year in the United Kingdom; in Japan, where X-rays and CT scans are more prevalent, they are responsible for 3.2% of all new cancers each year; and in Canada, X-rays are responsible for nearly 800 cancers each year.

Finally, a study was also done by U.S. researchers who looked at all patients who had CT scans in 2007 at Brigham and Women's Hospital and the Dana-Farber Cancer Institute.It was found that 7% of patients had a 1% increase in their risk of cancer due to CT scans。

From this, we can see that frequent CT examinations will increase the risk of causing cancer. Some scholars believe that when a patient undergoes a whole-body CT scan, the amount of radiation received is equivalent to the amount of radiation received by people located 2.5 kilometers from the atomic bombing centers of Hiroshima and Nagasaki in Japan.So that means that for every full-body CT scan that people receive, it increases the rate of cancer by 0.08%.

Although it is said so, we should not worry too much about having a CT examination, it is safer to have a CT examination 1~2 times a year, and the dose received is still within the safe range. Moreover, we face various kinds of radiation from nature in our daily life, such as the building materials of houses, the home appliances we use, and the exposure to sunlight, etc. In particular, the radiation absorbed at high altitude when we take an airplane is 10 times more than that on the ground. Therefore.As long as the human body's tolerable dose is not exceeded, i.e., a person's annual radiation dose does not exceed 100mSv, which is within the relatively safe range。

IV. How to reduce the radiation of CT examination as well as the radiation discharged from the body

The radiation of CT examination can be said to be quite large to the human body, we can only try to avoid doing CT examination, can not do CT examination, do not do, can do X-ray examination do X-ray examination, to be strictly in accordance with the indications for CT examination, we personally do not think that CT is more accurate to ask the doctor to open the CT checklist, so as to reduce the harm of radiation of CT examination to the human body.

In addition, when we have a CT scan, we may want to eat more of these foods, which can help to quickly expel radiation as well as resist it:

:: Honey and pollen: experiments conducted by the Institute of Aerospace Medicine of the Ministry of Nuclear Industry have proved that pollen protects the human immune system from radiation damage, and honey improves the body's resistance to radiation.

● ② carrots: regular consumption of carrots can make the body less vulnerable to radiation and ultraviolet radiation damage. This is because carrots contain a powerful antioxidant, which can effectively protect human cells, thus effectively combating cell cancer caused by radiation.

● ③ Tea: Tea contains anti-radiation substances can have a significant protective effect on the body's hematopoietic function, the scientific investigation found that people who often drink tea by radiation damage is lighter, the incidence of blood diseases is lower, and the mortality rate caused by radiation is also lower.

● ④ Fishweed: Fishweed not only has antibacterial and anti-inflammatory effects, but also has anti-radiation and enhancement of the immune function of the body, especially suitable for those who are often close to sources of radiation.

●⑤ Oranges and strawberries: oranges are rich in antioxidants, which can enhance the body's immunity and inhibit the growth of tumors. And strawberries contain a lot of vitamin E and polyphenol antioxidants, which can resist high-intensity radiation.

In conclusion, although the radiation of CT examination is much higher than that of X-ray examination and there is also the risk of cancer, there are some examinations that cannot be replaced by X-ray examination, and CT examination has its unique advantages, as long as we don't misuse CT examination, and perform CT examination only when necessary, so as to be able to effectively avoid CT radiation.

Author's note: I'm very happy to popularize health-related knowledge for everyone, I'm left-handed to say medical, every day in simple language for you to popularize professional medical knowledge, the code word is not easy, if you like my article, help me to point a praise! If you still have questions, you can leave a message in the comments section, welcome to pay attention to, forward, thank you for your support!

Thanks for the invitation. For this question, let's go straight to the data:

1. According to research, two percent of cancer patients may be caused by CT radiation.

2. A CT scan of the chest can emit 10 to 15 millisieverts of radiation in just one session. Mammography radiation amounts to 3 mSv.

3. If the dose of radiation is not very large, only short-term effects occur, the human body can repair itself, in the human harm is not too great. But if the dose is large, it can cause genetic damage, the formation of a variety of harmful biological effects, and due to increased radiation, can cause people for hematopoiesis, reproduction, development, hormone adjustment and other injuries will become greater. Mostly seen as killing white blood cells, resulting in lower blood diseases. Also, it can be detrimental to the thyroid gland, brain, skin and so on.

4, so do CT in the human body will have an impact. General radiological examination there is radiation, but as a necessary medical means, the amount of radiation is fixed, and in accordance with the principle of a small number of examinations generally will not have a major impact on human health, you can rest assured that the examination. Generally, 1 to 2 times a year, the human body does not have a great impact on the body, will not produce great harm.

Too much CT examination, although it will be detrimental to human health, but there is no definitive answer as to how much carcinogenicity exists. So don't worry too much, the necessary CT examination should still be done.

X线radiation dose：0.2mSv

chest X-rayradiation dose：1.1mSv

CTRadiation dose: 2-15mSv: head 2mSv; chest 8mSv; abdomen 10mSv

angiographyRadiation dose: 15mSv

For the general population, the normal annual intake of radiation due to environmental background radiation for the average person is 1 to 2 mSv per year.

Radiation-related workers are exposed to a maximum of 5mSv a year, and also need to be checked regularly, and if they exceed that they need to stop working immediately. It's this little box.

If we go by this standard, the number of head CTs a year should ideally be limited to 2 or less.

That's why it is said that CT should be done as little as possible! Especially for children, pregnant women who are frequently exposed to CT after a disease, many will be advised not to have children for a while.

However, there are times when a disease poses a far greater danger to a person than having a CT, and the trade-off is that it should be done. For example, in the case of a craniocerebral injury, where life is at stake, CT can detect bleeding in the skull within a minute and cannot be replaced by other tests.

If your doctor tells you to have a CT, it's basically a weighed choice, with little to no concern about the hospital making money with it.

Because a CT is getting cheaper and cheaper now, the most basic head CT may only cost $200 or so, and it will also be covered by health insurance. Hospitals don't have much room for profit.

Reading the comments, a lot of people say they had expensive CTs, most of which were probably enhanced scans or added multiple areas.

The state now has price limits, so check with your local price office to see what the CT limits are.

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CT, or computed tomography, utilizes the strong penetration of X-rays to scan the human body in layers of axes, and then uses computers to process the signals to produce a clear image of the diseased area as a whole, so as to diagnose the disease.

We all know that CT scanning has a high radiation dose, the average radiation dose is 6.6mSV, while doing a chest X-ray is only about 0.05mSV, so a CT scan is equivalent to doing more than 130 times a chest X-ray, and hospitals usually recommend that we only do a chest X-ray once every six months. So, is a CT scan with such a high radiation dose actually harmful to the human body? Will it cause cancer?

A review of relevant scientific studies published in international journals shows that CT scanning does have a certain relationship with the occurrence of certain cancers, and that CT causes cancer is not an empty rumor:

In 2009, Rebecca Smith-Bindman, Jafi Lipson, Ralph Marcus et al. published an article in the journal < Archives of internal medicine>: They assessed the cancer risk of 1,119 patients in the San Francisco, California, area who had CT scans between January and May 2008, and found that the risk of developing cancer after a CT scan was 1/270 in women and 1/600 in men, all at the age of 40 years. They found that for 40-year-old women, the risk of developing cancer after a CT scan was 1/270, compared with 1/600 for men.

And another 2013 study of CT and cancer risk rates in Australian teenagers (Bmj 346, f2360, 2013) also found:

The incidence of cancer was 24% higher in those who had a CT scan than in those who did not, especially for some solid cancers (e.g., cancers of the digestive organs, melanoma, soft tissues, female genitals, urinary tract, brain, and thyroid), leukemia, myelodysplasia, and other lymphoid cancers, which had a significantly higher incidence. The incidence of cancer was higher in the group that had a CT than in the group that did not, about 9.93 per 100,000 people.

So, having a CT still increases the risk of cancer. However, this article also mentions that as technology advances, CT radiation is becoming less and less and the technology is becoming more and more optimized, perhaps lowering the cancer risk rate even more.

Although CT increases the cancer risk rate to some degree, this risk rate is not high, not even as high as if you smoked and drank. If there are some diseases that are at the point where CT is a must, you still need to have a CT scan, which is more beneficial than detrimental.

Of course, if it's not necessary to do it, diseases that can be diagnosed using tests with minimal radiation such as MRIs and ultrasounds are better left alone if you can, after all.Radiation is real radiation.The medicine wouldn't know if it's good or not.

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Carcinogenicity definitely stems from radiation, and at one time it was recommended that CT exams be included in the annual medical checkup program in order to rule out diseases such as lung cancer, which is actually absolutely not recommended at this point in time!

What is the probability that a single CT will cause cancer in humans?

There is no doubt that the amount of radiation from one CT is equivalent to the radiation dose that would give you more than 400 regular X-rays!Because ordinary X-ray is equivalent to the same as we go to take a picture of a person, purely a surface shot, and CT is equivalent to dividing the person into several layers, and then take a shot, have several shots, look at them in layers, and really don't get it yet, think of a lasagna cake or a slice of bread!

But with more radiation than X-rays, it's still widely used in clinical practice, and there's a reason why you can't get away from it!In addition to it is clearer than ordinary X-ray, the most important thing is that it is layered, especially in some brain diseases such as tumors, hemorrhage and infarction as well as abdominal liver, kidneys own chest lungs and other parenchymal organs such as occupying lesions and so on the examination of the effect is better!

However, widespread use does not mean abuse, do a CT on the human body can be said to be extremely low probability of cancer, and even can say that at present have not found a do a must on cancer cases!But do more, the longer you do it, the amount of radiation your body is exposed to is certainly proportional, especially for some of the body is already relatively weak, a bit like chronic suicide, soOverseas, in fact, CT examination is very useful for some patients who are really suspected of having related diseases, and it is not recommended for healthy people, not to mention that it is treated as an "annual medical checkup program"!

But for the radiation of CT examination, we have to know a common sense, pay attention to the friends may find that in the hospital radiology department to take pictures of the door waiting for when theYou'll find a few big words on your door warning "Beware of Ionizing Radiation", and note, note, note, the culprit is "Ionizing Radiation".In fact, it is not the same as our usual life said radiation, life in the network, cell phones, wifi, telecom base stations and so on is belong to the "electromagnetic radiation".The biggest difference is: the harmful is ionizing radiation, not electromagnetic radiation, because ionizing radiation is related to radioactive elements, otherwise you think the hospital's "radiology" name is blindly taken it!And electromagnetic radiation is ubiquitous throughout the universe, is harmless I remember as a child the best example of this was the then indiscriminately blown radiation protection clothing worn by pregnant women, which typically later proved to be a scam!

So.Do not have nothing to do to go to the next house's network cable unplugged, that is harmless, something should have something to do should feel that they should take a CT check, tell the doctor that this quasi, up to a certain dose is really harmful!

Many people will come up with data to tell you how much radiation a CT is and how much a chest X-ray is, then compare them, and tell you that a chest CT is about 100 times more radioactive than a chest X-ray, or even 400 times more radioactive than a chest X-ray. In other words, one CT is equivalent to hundreds of chest X-rays.

It looks scary. It's actually not that scary.

Yes, radiation can cause cancer, there is nothing wrong with that. In the beginning, when we first discovered X-rays, we found that this light could take pictures, for example, a picture of a hand, and we could clearly see the bones (because different tissues have different densities), and it was very exciting, and the imaging doctors kept doing X-rays on their patients. It did help the clinic, but some people started to think something was wrong, because how come so many imaging doctors got cancer? It was only after careful analysis that we realized it was the X-rays that affected the imaging doctors, causing a genetic mutation and the development of cancer, which is more than one level higher than in the general population.

So people started working on protective materials and trying to reduce the dose of radiation, otherwise there would be no one working in imaging now.

However, a person who has a CT once a year, which is not a high frequency, will generally not be affected too much, but I believe there is no such exhaustive data on what the exact rate of cancer is, because when a person has cancer, you don't know whether it is caused by the radiation of the CT this time or something else, right? Some people even have one CT in their lifetime, which doesn't affect us significantly.

To summarize, the CT should be done, and don't be afraid of the radiation. Otherwise, it's just choking.

I'm an imaging physician who has been in a CT position for seven or eight years, and I can answer this question.

One type of damage to the human body from X-rays is called a deterministic effect. One is an indeterminate effect. And the main thing we usually protect against is to stop the deterministic ones and minimize the random effects.

There is no definitive data on the dangers of radiation to the human body. But for the known ones, you can check the background radiation of nature, and smokers check the radiation of smoking, the amount of a pack of cigarettes is no less than the amount of ct

For x-ray examination, should be correctly recognized, in order to medical diagnosis of the necessity of imaging examination is necessary. Now emphasize precision medicine, engaged in medical should know, now no matter what disease and case. Almost all of them start with imaging. Even if you are not a medical professional, it is not difficult to find the basis for your own online research.

Please do not say that doctors indiscriminately prescribe imaging tests, because open 100, he can not earn a penny more, to give a simple example, cerebral hemorrhage and cerebral infarction patients, the symptoms are too similar to their own Baidu to check against the good, but the treatment, one is a thrombolytic, while the other needs to stop bleeding, there is no imaging tests, is bound to increase a lot of medical malpractice.

No patient has ever come to the hospital and ended up being shot to death by radiation. Think about our imaging doctors, how many rays do they take every day? How many of them really get sick? We even joke that shooting is healthier.

Face up to the need for imaging tests, put yourself in the shoes of a person, you want to check the disease and then treat it or accept the treatment in a confused manner? In my career, I have encountered patients who are angry that they have spent money for nothing. It's also not unheard of to have a chest CT that didn't find anything and have the patient grind for an afternoon saying I didn't look at it properly. I don't know if you guys think this is a joke or if you think it was indeed wasted.

I am Dr. Shadow, a radiologist. At present, CT is widely popular, many people have heard of CT, and many of them have also done CT. CT examination has radiation, but at present, CT examination has an irreplaceable role in medical activities. Doing CT can quickly diagnose the condition, especially critical illnesses, and win time for patient treatment. This is where CT benefits mankind, but on the other hand, because it has radiation, short-term and multiple examinations, it may cause cancer. However, medical CT is not as scary as people think, and the idea of worrying that you will grow cancer after having two CTs is not necessary.

Radiation dose at common X-ray and CT sites

I'm sure you've all had chest x-rays, and the radiation dose for a chest x-ray is 0.02msv. Let's use the chest x-ray as a reference to see how much radiation you'll get from doing each part of the exam.

As shown in the figure, msv is the unit of radiation dose, and in a routine x-ray, the thoracolumbar spine has the largest dose, at 1 msv, because the vertebrae are bones, and it takes an increased dose to get the bones out.This is the radiation dose of CT routine parts, from the figure can be seen, CT radiation is greater than X-ray, which do CT enhancement or CTA radiation is greater than just do plain scanning, because the plain scanning is just scanning once, while enhancement or CTA need to scan many times, for example, to do CT abdomen, plain scanning only need to scan the abdomen once, but enhancement there are three phases, need to be more than three times scanning, so the dose is increased accordingly.

There are low radiation levels in nature.

Getting a CT scan is not as scary as you might think. Because radiation is everywhere in nature, we are exposed to natural radiation every minute of every day, called natural background radiation, which is usually about 2.0-3.0 mSv/year (mSv is a unit of measurement of radiation dose).

For example, the dose of a 20-hour airplane ride is 0.1mSv; the annual dose of 20 cigarettes smoked per day is 0.5-2mSv; and subway security passengers are likely to receive a dose of <0.01mSv per year. China's basic standards for radiological protection provide that the annual dose equivalent of a radioactive worker exposed to whole-body homogeneous irradiation should not exceed a maximum of 50mSv (5rem). The average annual dose should not exceed 20mSv. Radiation workers are required to wear dosimetric cards for daily work to detect radiation, and are tested quarterly. For members of the public, there are no specialized radiation dose cards.

How do you rationalize a CT exam?

CT examination in will cause harm to the human body, there are deterministic effect and random effect, deterministic effect is that the dose reaches a very large (several hundred msv), will increase the risk of cancer, but medical examination of the CT a few to a dozen msv far less than such radiation. Random effect means that the appearance of cancer is also random, and it does not mean that you will get cancer if you take a picture.

Biannual CT checkups are fine, but you should avoid multiple exposures to one area for a short period of time. The human body needs time to repair, and after a month of CT, the body has recovered. Of course it is best if you can do without. Some people may say that hospital patients with serious head injuries are having CT review every day, isn't that too much? If it is medically necessary to do it, it is recommended to do it. Because saving lives is important, this is the time to worry about radiation is more than enough.

A lot of irradiation doesn't necessarily mean you will get cancer, and those who don't get irradiated can get cancer. We as radiology staff, some of the older ones, give ourselves a one-time head, chest and abdomen CT scan every year. as professional radiologists, we are not blindly afraid because we understand.

Also, pregnant women try to avoid CT, especially in the first trimester. When you have a CT, you can use protective clothing to cover non-irradiated areas, especially glandular organs, such as the thyroid and gonads. Children should be especially protected when having the test, which is usually done in hospitals. For family members accompanying the CT examination, protective clothing can be worn. Each examination room, is already equipped with protective clothing, such as lead suits, lead caps and bibs.

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It's been nearly 50 years since doctors began using CT (computed tomography) scans in 1971, which help create more detailed three-dimensional images than traditional x-ray images.But.Researchers have long been concerned that CT medical imaging increases a patient's risk of developing cancer.CT scanners bombard the body with x-rays,...It's a form of ionizing radiation., which may damage DNA and create mutations that increase the probability of cellular cancer.

Radiation dose from CT scans

The radiation dose received by the human body from a CT scan is also 150 to 1,100 times that of a conventional x-ray, or the equivalent of a naturalenvironmentsAbout a year'sradiation dose.. Every person is exposed to ionizing radiation every day, from naturally occurring radioactive materials in the surrounding environment. Over the course of a year, the average person receives a radiation dose of about 3 millisieverts (mSv), compared to 1-10 mSv per CT scan (below).

The probability of cancer in CT scans

Researchers at the National Cancer Institute estimate that 72 million CT scans were performed in the U.S. in 2007, which could be expected to result in 29,000 cancer cases,...The equivalent of 2% of the 1.7 million cancers diagnosed in a year are induced by CT scansIn 2009, a study by the San Francisco Medical Center calculated an even higher risk:Every 400 to 2,000 chest CTs result in one cancer patient.。Some organs are more sensitive to radiation than others, such as the breasts, lungs, thyroid and bone marrow all have rapidly dividing cells, so they are more sensitive than other body parts to radiation.hemispheresMore sensitive, children are generally considered to be higher than adults.

In findings recently published in the Journal of the National Cancer Institute, it was revealed that CT scans may increase the risk of brain cancer. Among children and young adults, the most common malignancies are leukemia and brain tumors. Between 1979 and 2012, a total of 168,394 children in the Netherlands underwent one or more CT scans, and the overall cancer incidence was 1.5 times higher than expected. For brain tumors, the risk of cancer increased to two to four times at the highest doses, but the researchers did not observe an association between CT scans and leukemia. But the researchers warned thatThis CT cancer risk association may be due in part to relationship confounding, as CT scans themselves are sometimes used to identify with tumor risk; the reason these children had CT scans may be related to their cancer risk.

Over the past few decades, theMost scientists' estimates of cancer risk from CT scans rely heavily on cancer rates among long-term survivors of the atomic bombings in World War II.. A few years after the explosion, researchers began tracking the number of illnesses and deaths among the 120,000 survivors. The findings proved that the cancer risk of radiation depended on the dose, and that even very small doses increased the chances of disease. Based on these data, a 2006 report by the National Research Council estimated thatexposureCT scanning of the abdomen (10 mSv) increases the dose of the0.1%Lifetime risk of cancer. Based on the same basic information, FDA concluded that the10 mSv increased the risk of death by 0.05%。

Benefits of CT scans outweigh risks

The natural incidence of cancer over the average person's lifetime is about 20%, so the chances of getting cancer from a CT scan are very low. For most people, a CT scan is worth the risk of exposure to radiation, CT-scans greatly improve diagnostic capabilitiesthat can help doctors detect dangerous health problems in a timely manner, with the benefits outweighing the risks.