Lao Liu is 67 years old this year, and he has to do imaging examinations every year for physical examination, in previous years, because he was afraid that CT would have radiation, he only dared to do ultrasound projects, and later heard that MRI has no radiation hazards, and the light is clearer than CT, so he wanted to do a fine MRI to see how healthy the body is.
Unexpectedly, the doctor looked at his examination results in previous years and learned that it was his first time to do CT, so he politely rejected his idea of wanting a full-body MRI and only recommended an MRI of some organs.
Lao Liu looked puzzled, he didn't understand why MRI was more expensive, but the doctor didn't let it be done easily, could it be that MRI is more harmful than CT? Let's talk about this problem today.
1. How much radiation does CT cause, and does it really affect health?
Common imaging examinations include ultrasound, CT and MRI, etc., and the clarity and price of the examination are also rising, but in reality, there is a strange phenomenon, the cheapest and most expensive ultrasound and MRI are done by many people, and the cost-effective CT is not cared for, which is related to the excessive publicity of the harm of CT radiation.
CT is a common medical imaging examination, which operates X-rays through the human body, and different tissues experience X-rays to produce different decays, reflecting the health status of the body according to the remaining dose of X-rays. The X-rays contain a certain amount of radiation, which may affect the human body.
For example, many people experience nausea and vomiting, lack of energy, dizziness and other discomforts after the first CT scan, or after multiple CT scans in a short period of time, which are related to excessive radiation. There are more people who show up to say it, and everyone gradually thinks that doing CT will damage their health, but they don't like to do it.
But in fact, there is natural radiation in our lives, and the radiation in the air mainly comes from radon, which will enter the human body with breathing and eating. There are statistics:
• Mainland citizens receive approximately 2.4-3.4 mSv of natural radiation per year, with an average of 6.6-9.3 svv per day.
At this level, our body can naturally metabolize and does not have much impact on health. How much radiation does a CT scan produce?
Modern CT technology is well developed, and a routine CT examination of the head has about 2 mSv of radiation, 8 mSv of the chest CT, and 10 mSv of the abdomen. The average upper limit of radiation received per year for 5 years is 20 mSv, which is enough to support the annual medical check-up program.
Therefore, CT examination does cause a certain amount of radiation, but as long as it is controlled within a certain range, the natural metabolism of the human body can withstand it, so there is no need to be too nervous.
2. Is MRI completely harmless? You don't even care about these hidden dangers
Let's talk about MRI again, it has no radiation and shines more clearly, why don't some doctors let it happen?
First of all, NMR is not very cost-effective.
MRI does shine more clearly, but the price is also more expensive, it costs more than 500 yuan to make an ordinary MRI of a part, and if the requirements are more refined, it may reach thousands of yuan. If it is used for routine inspection, it will directly increase the cost of inspection, and the cost performance is not high.
Therefore, MRI is often used as an option for secondary examination, such as relatively cheap ultrasound and CT during physical examination, and it is found that there is an abnormality, but it is not clear to see. At this time, it is necessary to supplement the MRI of some parts of the area to take a closer look at what is going on.
Secondly, there are some "hidden dangers" of MRI that we don't care about.
Nuclear magnetic resonance (NMR) essentially uses the changes in the body's hydrogen atoms in a strong magnetic field to feedback electromagnetic signals to form imaging. When the human body is exposed to this strong magnetic field, it may also cause certain harm.
In the early years, researchers experimented with mice and irradiated them in a strong magnetic field for 2 hours, and found that:
• The vestibular system of mice is dysfunctional.
This shows that long-term and frequent exposure to abnormal magnetic fields may indeed be detrimental to health.
And people who have had an MRI may find that there is a noticeable noise during the examination, which is related to the gradient field of the MRI. MRI needs to rely on gradient field for spatial localization to clarify the position and morphology of organs and tissues for better imaging.
When the gradient field is too strong, our body will not only experience a tingling sensation, but also hear more pronounced, high-pitched noise, which may affect hearing and even cause temporary or permanent deafness in patients with low tolerance.
Therefore, whether you are suitable for doing it, under what circumstances, and what part of the MRI need to be judged by the doctor in order to get the maximum benefit.
3. Do CT and MRI need to be done, and what items do I need to choose for a comprehensive physical examination?
CT and MRI are both imaging examinations, why do some people not have done it, some people have done one, and some people have to do both?
1. Basic items
The basic items refer to the basic items that must be done in the physical examination, such as physical examination, blood routine, stool routine, immune examination, tumor serological examination, and imaging examinations such as electrocardiogram and CT.
Most of them are routine laboratory tests, which are to take some body fluids to test the components and observe the basic condition of the body to determine which organs and tissues may have abnormalities.
There are many options for imaging examinations, such as ultrasound, CT, MRI, etc., and if you are usually healthy, you can choose relatively cheap ultrasound, CT, and you can also check for diseases. If you have health problems, such as coronary heart disease, cerebral thrombosis, etc., it is recommended to supplement more delicate MRI to make it easier to observe the condition.
2. Individualized projects
If you have a medical condition, or if you are entering the age of high incidence of some diseases, you need to supplement the individualized examination.
For example, patients with cardiovascular and cerebrovascular diseases or people with high incidence are recommended to supplement hypersensitive C-reactive protein, high-bright troponin, carotid artery ultrasound, blood lipid omnidirection, cerebrovascular function score and other examinations.
If you want to check for malignant tumors, it is recommended to supplement carcinoembryonic antigen, low-dose spiral, lung cancer autoantibody detection, cervical cancer examination, colorectoscopy and other targeted examinations. For those with metabolism-related diseases, fasting insulin, fasting C-peptide, bone density, blood calcium content, etc. can be investigated in detail.
3. Mental health and physical activity programs
In addition to internal check-ups, we also need to be concerned about athletic ability and mental health.
It is recommended to do a mental health assessment, such as anxiety self-rating scale, depression self-rating scale, stress self-rating scale, sleep quality assessment, etc., to briefly look at your psychological condition.
Exercise ability needs to be evaluated by the doctor, such as whether the body can maintain a normal posture, whether the body shape is healthy during exercise, whether there are abnormalities in the grip of fingers, the bearing capacity of the lower back, the jumping ability of the legs, and the balance of the body, so as to determine whether the motor nerves and muscles are healthy.
4. "Traditional Chinese Medicine Treats Diseases" project
In recent years, the rise of traditional Chinese medicine has gradually incorporated traditional Chinese medicine examinations into the scope of routine examinations.
Traditional Chinese medicine has a great advantage in the treatment of diseases, they believe that the five internal organs of the human body have their own functions, they contain each other, promote each other, in order to maintain the normal function of the body, and most diseases are caused by the decline of the internal organs themselves, which affects other organs.
Therefore, Chinese medicine can regulate the function of the internal organs in advance, help the organs maintain their own balance, and prevent the emergence of a variety of diseases as much as possible, which does not necessarily require taking medicine, but can also be achieved by changing dietary Xi habits and maintaining regular exercise.
Citations:
[1] Luo Chengxiang. How harmful is CT examination[J].Health Guide,2022,28(03):55.)
Electronic Journal of Cardiovascular Diseases,2016,4(34):119.DOI:10.16282/j.cnki.cn11-9336/r.2016.34.201