Fluorography (FLG) or X-ray fluorography is a type of X-ray examination. It consists in photographing organs and tissues on a film from a fluorescent screen and displaying the image on a monitor or picture. The method is based on the fact that the density of various organs (heart, blood vessels, lungs) is not the same, therefore, when x-rays pass through them, negatives are obtained - dark and light areas. The process resembles photography and is projected onto film. Another name for FLG is radio photography.
In the pictures, the cavities with air are black, the bones are white, and the soft tissues are different shades of gray. The results of the received image on a computer are processed to give an opinion. The radiation dose during lung fluorography during such a survey is equal to that which a person will receive when using home appliances at home for 2 weeks.
X-ray concept
This is the electromagnetic radiation of ionized particles in the spectrum between gamma and ultraviolet. It is the basis for the diagnosis of many diseases. X-rays are unique in that they are not refracted or reflected. The fluorography exposure dose corresponds to a continuous weekly exposure to the sun.
Is there any harm from x-rays to the body
Many patients are concerned about the negative effects of x-rays on the body. When passing through the human body, the rays ionize it. Tissues and organs absorb them to varying degrees, then they talk about their susceptibility. At the same time, the structure of molecules and atoms changes - they simply charge. This can lead to somatic disorders, in women - genetic disorders of the offspring.
X-rays affect organs in different ways. To account for such manifestations, there is a concept - the coefficient of radiation risk for the corresponding organ or tissue. It determines the likelihood of harm after radiation. A high coefficient is a high susceptibility of tissue. And, consequently, the damage from radiation is also higher. The most susceptible are hemopoietic organs, especially red bone marrow. Therefore, in this system, pathologies arise primarily. With minor exposure, they are reversible; with more - red blood cells and hemoglobin decay.
There may be leukemia, erythrocytopenia, leading to organ hypoxia, a decrease in platelets. Cells of the outer layer of the vessel wall are also damaged.
The lungs, heart and nerves of an adult are quite radio-stable. Children and adolescents have not yet completed their development and their cells are actively dividing, so the mutational effect of x-rays increases. Fluorography is allowed only from the age of 15. Also, the procedure is not done for pregnant and lactating women.
Other possible pathologies:
- development of oncology;
- early aging
- cataract with damage to the lens of the eye.
And what in practice? In medical equipment, a beam of short duration and energy is used, therefore, even with repeated exposure during examinations, there is no harm to the body. For example, a single exposure during radiography will increase the risk of oncology in the distant future by only 0.001%. Judge for yourself how much it is.
Radioactive rays cease to function after the device is turned off immediately. Why? Because they are electromagnetic waves, in fact. They do not accumulate, do not form other radioactive substances that could be sources of independent radiation.
Conclusion: there is no need to take drastic measures to reduce radiation after an X-ray examination, but do not resort to other medical procedures.
Roentgenography
It is highly informative, affordable and has been leading the way in diagnostics for over 100 years. The method is highly informative. In the picture of the lungs, shadows are detected even about 2 mm. FLH does not reveal them.
Film fluorography
Gives an x-ray image in a noticeably reduced size. The maximum is 10 cm, the minimum is 2.5 cm. There is no need to speak about the quality of the image. In practice, this is only a copy of a small chest image. The image is fixed on a photosensitive film.
Film FLG is an outdated method and is not used in developed countries. It requires a lot of conditions:
- for the manifestation of the picture it takes time and special equipment;
- the quality of the pictures is so low that to conclude the doctor must use a magnifying glass when examining them.
And the biggest minus of this method is that with digital fluorography, the radiation dose is higher here.
Digital fluorography
Modern technologies allow research with a much lower radiation dose, and the quality of the image is high. The image is transferred to electronic media. When working with digital fluorography, exposure to power can be changed in latitude from 10 to 50 mR at the discretion of the doctor.
Digital equipment allows you to quickly carry out any large-scale research. Primary processing of images is very fast by software. Research results can be stored on a computer for an unlimited time. The only drawback of digital FLG is the high cost of equipment. In this regard, not every hospital can use the method.
The safest and most modern way is to scan the chest, which makes a digital scanning fluorograph. With this method, the emitter and the reception detector move along the body of the person under study. Image line up computer. Radiation load is reduced by 30 times. In addition, the image quality is higher due to the use of a narrow beam of energy, which minimizes the effect of scattered radiation. This becomes relevant when examining patients with increased weight.
The information content of scanned images reaches 80%, and additional radiography after them is not required. This further reduces the radiation dose in summation.
Units
In X-ray diagnostics, X-ray and sievert are used. The x-ray machine gives the level of penetrating radiation in x-rays (P). They measure the total radiation. The response of biological tissues is measured in sievert (Sv).
Sievert is a unit of measurement of doses of ionizing radiation in the International System of Units (SI), which was introduced since 1979. Sievert (in honor of the Swedish radiophysicist R. Sievert) is, in fact, the amount of energy equal to the effect of the absorbed dose of gamma radiation of 1 Gray per 1 kg of biological tissue. Simply put, this is the dose a person receives.
Sievert is approximately equal to 100 x-rays. 1 P is approximately equal to 0.0098 Sv (0.01 Sv).
Due to the fact that the radiation doses in medical X-ray equipment are much lower than those indicated, thousandths (milli) and millionths of (micro) Sievert and X-ray are used to express them.
In numbers, this is expressed as follows: 1 sievert (Sv) = 1000 millisievert (mSv) = 1,000,000 microsievert (μSv).
The same goes for x-rays. There is also the concept of dose rate - the amount of radiation per unit time (hour, minute, second). It is measured, for example, in Sv / h (sievert hour), etc.
How many sievert do people get
Sievert measures the amount of radiation passing through the body per unit time, usually in an hour. Then they accumulate throughout life.
Since 2010, SanPiN 2.6.1.2523-09 "Radiation Safety Standards NRB-99/2009" has been in force in the Russian Federation. According to him, the maximum dose for a year should normally not exceed 1 thousand μSv.
If during treatment there is a need for repeated x-rays, a radiation passport is made for the patient, which must be strictly stored in an outpatient card. It should note all radiation doses received during treatment.
Diagnostic irradiation
The dose for x-ray and chest x-ray diffraction differs in favor of x-ray: 0.3 mSv, which is less than with x-ray.
But it is worth considering that when an X-ray of the lungs, the picture is usually taken in two projections, and then the radiation dose doubles.
In a digital study, the exposure rate is 0.04 mSv. Film fluorography gives an exposure dose of 0.5-0.8 mSv, lung X-ray - 0.1-0.2 mSv.
The radiation dose for CT, which is prescribed for suspected cancer and tuberculosis, ranges from 2 to 9 mSv, which is much higher than fluorography.
The radiation doses for fluorography, X-ray and MSCT (multispiral computed tomography) are different, for example, the radiation dose in the latter method is 30% lower than CT. The images in this examination are layered, so even the smallest tissue disorders that are not available in a conventional radiograph are detected.
Ultrasound and MRI do not irradiate the body.
How to reduce x-ray damage
Physicists in radiation recommend 3 methods:
- reduce the time spent;
- increase the distance from the emitter;
- apply protective shields with a layer of lead.
If the residence time can still be changed, then the distance cannot be adjusted. Safety shields can protect human gonad cells. They are made in the form of "skirts". When conducting x-ray examination of the patient is protected with a lead apron. Children undergo a full film adaptation of the body with a window of the local shooting area.
Research dose rates
When passing FLG annually, the radiation dose is 50-80 μSv. If the maximum per year should not exceed 1000, here the supply is large, and with the digital FLG method the indicator 4-15 μSv is even larger.
The radiation dose during fluorography on a conventional apparatus is on average 0.3 mSv, and when using digital technology it will be only 0.05 mSv. The difference is noticeable, especially if the x-ray has to be repeated repeatedly. Therefore, recording on the picture, it is better to clarify the radiation dose. After the procedure, pay attention to the numbers indicated by the radiologist. It is advisable to save data so as not to exceed the permitted total annual dose.
What is available fluorography
The FLG procedure is prophylactic. Many pathologies do not manifest themselves for a long time, and early diagnosis will increase the chance of recovery. Preventive examinations allow you to diagnose:
- tuberculosis;
- oncology;
- inflammation
- condition of the bronchi;
- pneumo- or hydrothorax;
- vascular sclerosis;
- fibrosis.
In this case, early diagnosis can be combined with other types of research by specialized specialists.
What is preferable x-ray or FLG
What is the radiation dose for fluorography? The maximum values were observed with film FLG, amounting to 50% of the recommended norm in the case of a single examination, i.e. 0.5 mSv. In digital imaging, these values are only 3% of the annual dose, i.e. 0.03 mSv.
The exposure dose for fluorography in μSv in the digital version is 30. In reality, these average values can fluctuate in any direction.
What is done in clinics and why
So, if the safe radiation dose for fluorography is 1 mSv / year, FLG without fear can be passed 2 times a year. And if you have to do it again, for example, if you suspect any pathology, the dose will exceed the permissible norm. But is repetition always necessary? For a sanitary book, enough once a year.
Fresh data is needed only when obtaining a driver’s license. But there are certain categories of citizens and professions in which the FLG is appointed once every 6 months.
The radiation dose for fluorography and radiography of the lungs looks like this: 5 mSv and 0.16 mSv, respectively. If you have been prescribed fluorography, perhaps there is a safer way to diagnose this outpatient clinic, even if it’s paid. You can choose.
Fluorography is the leader in demand in medical institutions due to the low cost compared with MRI and CT. Even despite the fact that her conclusions give only generalized data on the state of the heart and lungs, compared with x-rays. Why are doctors stubbornly sending everyone to the FLG, radiation more dangerous and less informative? Moreover, any appeal to the clinic, not even in the case of a cold, rests on the appointment of a doctor for FLH.
Just an informative x-ray - the procedure is more expensive. And let the radiation dose for fluorography is higher than for radiography. The reasons most often rest on the following:
- there is no digital device in the hospital;
- radiography is paid, and a physical examination should be free;
- device on the road;
- X-ray does not work.
In addition, FLG is much cheaper. Costly X-ray films contain silver and are not suitable for mass screening. This is too expensive a pleasure for large-scale research. Examination should be carried out every year. The cost of the procedure becomes a priority for the state.
FLG brings tremendous savings to the government on supplies and is available in remote areas, enabling massive research. This is a screening diagnostic method. The procedure takes about a minute and the throughput is 150 people per day. In this regard, FLG is indispensable.