X radiation. Basic properties of X-ray radiation

X-rays play a huge role in modern medicine; the history of the discovery of X-rays dates back to the 19th century.

X-rays are electromagnetic waves that are produced with the participation of electrons. When charged particles are strongly accelerated, artificial X-rays are created. It passes through special equipment:

• charged particle accelerators.

History of discovery

These rays were invented in 1895 by the German scientist Roentgen: while working with a cathode ray tube, he discovered the fluorescence effect of barium platinum cyanide. It was then that such rays and their amazing ability to penetrate the tissues of the body were described. The rays became known as x-rays (x-rays). Later in Russia they began to be called X-ray.

X-rays can even penetrate walls. So Roentgen realized that he had made the greatest discovery in the field of medicine. It was from this time that separate sections in science began to form, such as radiology and radiology.

The rays are able to penetrate through soft tissue, but are delayed, their length is determined by the obstacle of the hard surface. The soft tissues in the human body are skin, and the hard tissues are bones. In 1901, the scientist was awarded the Nobel Prize.

However, even before the discovery of Wilhelm Conrad Roentgen, other scientists were also interested in a similar topic. In 1853, French physicist Antoine-Philibert Mason studied a high-voltage discharge between electrodes in a glass tube. The gas contained in it began to release a reddish glow at low pressure. Pumping out excess gas from the tube led to the disintegration of the glow into a complex sequence of individual luminous layers, the hue of which depended on the amount of gas.

In 1878, William Crookes (English physicist) suggested that fluorescence occurs due to the impact of rays on the glass surface of the tube. But all these studies were not published anywhere, so Roentgen had no idea about such discoveries. After publishing his discoveries in 1895 in a scientific journal, where the scientist wrote that all bodies are transparent to these rays, although to very different degrees, other scientists became interested in similar experiments. They confirmed the invention of Roentgen, and subsequently the development and improvement of X-rays began.

Wilhelm Roentgen himself published two more scientific papers on the topic of X-rays in 1896 and 1897, after which he took up other activities. Thus, several scientists invented it, but it was Roentgen who published scientific works on this subject.

Principles of image acquisition

The features of this radiation are determined by the very nature of their appearance. Radiation occurs due to an electromagnetic wave. Its main properties include:

1. Reflection. If a wave hits the surface perpendicularly, it will not be reflected. In some situations, diamond has the property of reflection.
2. Ability to penetrate tissue. In addition, rays can pass through opaque surfaces of materials such as wood, paper, etc.
3. Absorption. Absorption depends on the density of the material: the denser it is, the more X-rays absorb it.
4. Some substances fluoresce, that is, glow. As soon as the radiation stops, the glow also goes away. If it continues after the cessation of the rays, then this effect is called phosphorescence.
5. X-rays can illuminate photographic film, just like visible light.
6. If the beam passes through the air, then ionization occurs in the atmosphere. This state is called electrically conductive, and it is determined using a dosimeter, which sets the radiation dosage rate.

Radiation - harm and benefit

When the discovery was made, the physicist Roentgen could not even imagine how dangerous his invention was. In the old days, all devices that produced radiation were far from perfect and ended up with large doses of released rays. People did not understand the danger of such radiation. Although some scientists even then put forward theories about the dangers of X-rays.

X-rays, penetrating into tissues, have a biological effect on them. The unit of measurement for radiation dose is roentgen per hour. The main influence is on the ionizing atoms that are located inside the tissues. These rays act directly on the DNA structure of a living cell. The consequences of uncontrolled radiation include:

• cell mutation;
• the appearance of tumors;
• radiation burns;
• radiation sickness.

Contraindications to X-ray examinations:

1. The patients are in serious condition.
2. Pregnancy period due to negative effects on the fetus.
3. Patients with bleeding or open pneumothorax.

How does x-ray work and where is it used?

1. In medicine. X-ray diagnostics is used to examine living tissues in order to identify certain disorders within the body. X-ray therapy is performed to eliminate tumor formations.
2. In science. The structure of substances and the nature of x-rays are revealed. These issues are dealt with by such sciences as chemistry, biochemistry, and crystallography.
3. In industry. To detect irregularities in metal products.
4. For the safety of the population. X-rays are installed in airports and other public places to scan luggage.

Medical uses of x-ray radiation. In medicine and dentistry, X-rays are widely used for the following purposes:

1. To diagnose diseases.
2. For monitoring metabolic processes.
3. For the treatment of many diseases.

The use of X-rays for medicinal purposes

In addition to detecting bone fractures, X-rays are widely used for therapeutic purposes. The specialized application of x-rays is to achieve the following goals:

1. To destroy cancer cells.
2. To reduce tumor size.
3. To reduce pain.

For example, radioactive iodine, used for endocrinological diseases, is actively used for thyroid cancer, thereby helping many people get rid of this terrible disease. Currently, to diagnose complex diseases, X-rays are connected to computers, resulting in the emergence of the latest research methods, such as computed axial tomography.

These scans provide doctors with color images that show a person's internal organs. To detect the functioning of internal organs, a small dose of radiation is sufficient. X-rays are also widely used in physiotherapy.

Basic properties of X-rays

1. Penetrating ability. All bodies are transparent to the X-ray beam, and the degree of transparency depends on the thickness of the body. It is thanks to this property that the beam began to be used in medicine to detect the functioning of organs, the presence of fractures and foreign bodies in the body.
2. They are capable of causing some objects to glow. For example, if barium and platinum are applied to cardboard, then, after passing through scanning rays, it will glow greenish-yellow. If you place your hand between the X-ray tube and the screen, the light will penetrate more into the bone than into the tissue, so bone tissue will appear brightest on the screen, and muscle tissue less brightly.
3. Action on photographic film. X-rays can, like light, make a film dark, this allows you to photograph the shadow side that is obtained when examining bodies with X-rays.
4. X-rays can ionize gases. This allows not only to find the rays, but also to determine their intensity by measuring the ionization current in the gas.
5. They have a biochemical effect on the body of living beings. Thanks to this property, X-rays have found wide application in medicine: they can treat both skin diseases and diseases of internal organs. In this case, the desired dosage of radiation and the duration of the rays are selected. Prolonged and excessive use of such treatment is very harmful and detrimental to the body.

The use of X-rays has resulted in the saving of many human lives. X-rays not only help to diagnose the disease in a timely manner; treatment methods using radiation therapy relieve patients from various pathologies, from hyperfunction of the thyroid gland to malignant tumors of bone tissue.

X-RAY

X-ray radiation occupies the region of the electromagnetic spectrum between gamma and ultraviolet radiation and is electromagnetic radiation with a wavelength from 10 -14 to 10 -7 m. In medicine, X-ray radiation with a wavelength from 5 x 10 -12 to 2.5 x 10 -10 is used m, that is, 0.05 - 2.5 angstroms, and for X-ray diagnostics itself - 0.1 angstroms. Radiation is a stream of quanta (photons) propagating linearly at the speed of light (300,000 km/s). These quanta have no electrical charge. The mass of a quantum is an insignificant part of an atomic mass unit.

Energy of quanta measured in Joules (J), but in practice they often use a non-systemic unit "electron-volt" (eV) . One electron volt is the energy that one electron acquires when passing through a potential difference of 1 volt in an electric field. 1 eV = 1.6 10~ 19 J. The derivatives are the kiloelectron-volt (keV), equal to a thousand eV, and the megaelectron-volt (MeV), equal to a million eV.

X-rays are produced using X-ray tubes, linear accelerators and betatrons. In an X-ray tube, the potential difference between the cathode and the target anode (tens of kilovolts) accelerates the electrons bombarding the anode. X-ray radiation occurs when fast electrons are decelerated in the electric field of the atoms of the anode substance (bremsstrahlung) or during the restructuring of the inner shells of atoms (characteristic radiation) . Characteristic X-ray radiation has a discrete nature and occurs when the electrons of the atoms of the anode substance transfer from one energy level to another under the influence of external electrons or radiation quanta. Bremsstrahlung X-rays has a continuous spectrum depending on the anode voltage on the X-ray tube. When braking in the anode substance, electrons spend most of their energy on heating the anode (99%) and only a small fraction (1%) is converted into X-ray energy. In X-ray diagnostics, bremsstrahlung radiation is most often used.

The basic properties of X-rays are characteristic of all electromagnetic radiation, but there are some special features. X-rays have the following properties:

- invisibility - sensitive cells of the human retina do not respond to X-rays, since their wavelength is thousands of times shorter than that of visible light;

- straight propagation – rays are refracted, polarized (propagated in a certain plane) and diffracted, like visible light. The refractive index differs very little from unity;

- penetrating power - penetrate without significant absorption through significant layers of substances opaque to visible light. The shorter the wavelength, the greater the penetrating power of x-rays;

- absorption capacity - have the ability to be absorbed by body tissues; all x-ray diagnostics are based on this. The absorption capacity depends on the specific gravity of the tissue (the higher, the greater the absorption); on the thickness of the object; on the radiation hardness;

- photographic action - decompose silver halide compounds, including those found in photographic emulsions, which makes it possible to obtain X-ray images;

- luminescent effect - cause luminescence of a number of chemical compounds (luminophores), the X-ray transillumination technique is based on this. The intensity of the glow depends on the structure of the fluorescent substance, its quantity and distance from the X-ray source. Phosphors are used not only to obtain images of objects under study on a fluoroscopic screen, but also in radiography, where they make it possible to increase the radiation exposure to the radiographic film in the cassette due to the use of intensifying screens, the surface layer of which is made of fluorescent substances;

- ionization effect - have the ability to cause the disintegration of neutral atoms into positively and negatively charged particles, dosimetry is based on this. The effect of ionization of any medium is the formation in it of positive and negative ions, as well as free electrons from neutral atoms and molecules of the substance. Ionization of the air in the X-ray room during operation of the X-ray tube leads to an increase in the electrical conductivity of the air and an increase in static electric charges on cabinet objects. In order to eliminate such undesirable effects, forced supply and exhaust ventilation is provided in X-ray rooms;

- biological effect - have an impact on biological objects, in most cases this impact is harmful;

- inverse square law - for a point source of X-ray radiation, the intensity decreases in proportion to the square of the distance to the source.

They are emitted with the participation of electrons, in contrast to gamma radiation, which is nuclear. Artificially, X-rays are created by strongly accelerating charged particles and by electrons passing from one energy level to another, releasing large amounts of energy. The devices that can be used are X-ray tubes and charged particle accelerators. Its natural sources are radioactively unstable atoms and space objects.

History of discovery

It was made in November 1895 by Roentgen, a German scientist who discovered the fluorescence effect of barium platinum cyanide during operation of a cathode ray tube. He described the characteristics of these rays in some detail, including their ability to penetrate living tissue. Scientists called them X-rays; the name “X-ray” took root in Russia later.

What is this type of radiation characterized by?

It is logical that the features of this radiation are determined by its nature. An electromagnetic wave is what X-rays are. Its properties are as follows:

X-ray radiation - harm

Of course, at the time of its discovery and for many years after, no one realized how dangerous it was.

Where are X-rays used?

1. Medicine. X-ray diagnostics is the “examination” of living organisms. X-ray therapy affects tumor cells.
2. The science. Crystallography, chemistry and biochemistry use them to reveal the structure of matter.
3. Industry. Detection of defects in metal parts.
4. Safety. X-ray equipment is used to detect dangerous items in luggage at airports and other places.

1. 
   High penetrating ability - able to penetrate certain media. X-rays penetrate best through gaseous media (lung tissue); they penetrate poorly through substances with high electron density and high atomic mass (in humans, bones).
2. 
   Fluorescence - glow. In this case, the energy of X-ray radiation is converted into the energy of visible light. Currently, the principle of fluorescence underlies the design of intensifying screens designed for additional exposure of X-ray film. This allows you to reduce the radiation load on the body of the patient being studied.
3. 
   Photochemical – the ability to induce various chemical reactions.
4. 
   Ionizing ability - under the influence of X-rays, atoms are ionized (decomposition of neutral molecules into positive and negative ions that make up an ion pair.
5. 
   Biological – cell damage. For the most part, it is caused by the ionization of biologically significant structures (DNA, RNA, protein molecules, amino acids, water). Positive biological effects - antitumor, anti-inflammatory.

1. 
   Beam tube device

X-rays are produced in an X-ray tube. An X-ray tube is a glass container with a vacuum inside. There are 2 electrodes - cathode and anode. The cathode is a thin tungsten spiral. The anode in the old tubes was a heavy copper rod with a beveled surface facing the cathode. A plate of refractory metal was soldered onto the beveled surface of the anode - a mirror of the anode (the anode gets very hot during operation). In the center of the mirror is X-ray tube focus- This is the place where X-rays are produced. The smaller the focus value, the clearer the contours of the subject being photographed. Small focus is considered to be 1x1 mm, or even less.

In modern X-ray machines, electrodes are made from refractory metals. Typically tubes with a rotating anode are used. During operation, the anode is rotated using a special device, and electrons flying from the cathode fall on the optical focus. Due to the rotation of the anode, the position of the optical focus changes all the time, so such tubes are more durable and do not wear out for a long time.

How are X-rays produced? First, the cathode filament is heated. To do this, using a step-down transformer, the voltage on the tube is reduced from 220 to 12-15V. The cathode filament heats up, the electrons in it begin to move faster, some of the electrons leave the filament and a cloud of free electrons forms around it. After this, a high voltage current is turned on, which is obtained using a step-up transformer. Diagnostic X-ray machines use high voltage current from 40 to 125 kV (1 kV = 1000 V). The higher the voltage on the tube, the shorter the wavelength. When the high voltage is turned on, a large potential difference is obtained at the poles of the tube, electrons “break away” from the cathode and rush to the anode at high speed (the tube is the simplest accelerator of charged particles). Thanks to special devices, electrons do not scatter to the sides, but fall into almost one point of the anode - the focus (focal spot) and are decelerated in the electric field of the anode atoms. When electrons are decelerated, electromagnetic waves arise, i.e. X-rays. Thanks to a special device (in old tubes - a beveled anode), X-rays are directed at the patient in the form of a diverging beam of rays, a “cone”.

1. 
   Obtaining an X-ray image

X-ray film is a layered structure, the main layer is a polyester composition up to 175 microns thick, coated with a photoemulsion (silver iodide and bromide, gelatin).

1. 
   Developing the film - silver is restored (where the rays passed through - blackening of the area of ​​the film, where they lingered - lighter areas)
2. 
   Fixer - washing out silver bromide from areas where the rays passed through and did not linger.

1. 
   Construction of a modern X-ray room

1. The X-ray room itself, where the machine is located and patients are examined. The area of ​​the X-ray room must be at least 50 m2

2. The control room, where the control panel is located, with the help of which the x-ray technician controls the entire operation of the device.

3. A darkroom where film cassettes are loaded, photographs are developed and fixed, they are washed and dried. A modern method of photographic processing of medical X-ray films is the use of roll-type developing machines. In addition to undoubted ease of use, developing machines provide high stability of the photo processing process. The time for a complete cycle from the moment the film enters the developing machine until a dry radiograph is obtained (“from dry to dry”) does not exceed several minutes.

4. Doctor's office, where the radiologist analyzes and describes the radiographs taken.

1. 
   Methods of protection for medical personnel and patients from X-ray radiation

3 main methods of protection: protection by shielding, distance and time.

1 .Shielding protection:

Special devices made of materials that absorb X-rays well are placed in the path of X-rays. It can be lead, concrete, barite concrete, etc. The walls, floors, and ceilings in X-ray rooms are protected and made of materials that do not transmit rays to adjacent rooms. The doors are protected with lead-lined material. The viewing windows between the X-ray room and the control room are made of leaded glass. The X-ray tube is placed in a special protective casing that does not allow X-rays to pass through and the rays are directed at the patient through a special “window”. A tube is attached to the window, limiting the size of the X-ray beam. In addition, an X-ray machine diaphragm is installed at the exit of the rays from the tube. It consists of 2 pairs of plates perpendicular to each other. These plates can be moved and pulled apart like curtains. This way you can increase or decrease the irradiation field. The larger the irradiation field, the greater the harm, so aperture- an important part of protection, especially in children. In addition, the doctor himself is exposed to less radiation. And the quality of the pictures will be better. Another example of shielding is that those parts of the subject’s body that are not currently subject to filming should be covered with sheets of leaded rubber. There are also aprons, skirts, and gloves made of special protective material.

2 .Time protection:

The patient should be irradiated during an X-ray examination for as little time as possible (hurry, but not to the detriment of diagnosis). In this sense, images give less radiation exposure than transillumination, because Very short shutter speeds (time) are used in the photographs. Time protection is the main way to protect both the patient and the radiologist himself. When examining patients, the doctor, all other things being equal, tries to choose a research method that takes less time, but not to the detriment of diagnosis. In this sense, fluoroscopy is more harmful, but, unfortunately, it is often impossible to do without fluoroscopy. Thus, when examining the esophagus, stomach, and intestines, both methods are used. When choosing a research method, we are guided by the rule that the benefits of the research should be greater than the harm. Sometimes, due to the fear of taking an extra photo, errors in diagnosis occur and treatment is prescribed incorrectly, which sometimes costs the patient’s life. We must remember about the dangers of radiation, but do not be afraid of it, it is worse for the patient.

3 .Protection by distance:

According to the quadratic law of light, the illumination of a particular surface is inversely proportional to the square of the distance from the light source to the illuminated surface. In relation to x-ray examination, this means that the radiation dose is inversely proportional to the square of the distance from the focus of the x-ray tube to the patient (focal length). When the focal length increases by 2 times, the radiation dose decreases by 4 times, and when the focal length increases by 3 times, the radiation dose decreases by 9 times.

During fluoroscopy, a focal length of less than 35 cm is not allowed. The distance from the walls to the X-ray machine must be at least 2 m, otherwise secondary rays are formed, which occur when the primary beam of rays hits surrounding objects (walls, etc.). For the same reason, unnecessary furniture is not allowed in X-ray rooms. Sometimes, when examining severely ill patients, the staff of the surgical and therapeutic departments helps the patient stand behind the X-ray screen and stand next to the patient during the examination, supporting him. This is acceptable as an exception. But the radiologist must ensure that nurses and nurses helping the patient wear a protective apron and gloves and, if possible, do not stand close to the patient (protection by distance). If several patients come to the X-ray room, they are called into the treatment room one person at a time, i.e. There should be only 1 person at the moment of the study.

1. 
   Physical foundations of radiography and fluorography. Their disadvantages and advantages. Advantages of digital over film.

When performing diagnostic radiography, it is advisable to take pictures in at least two projections. This is due to the fact that an x-ray is a flat image of a three-dimensional object. And as a consequence, the localization of the detected pathological focus can be established only using 2 projections.

The quality of the resulting x-ray image is determined by 3 main parameters. The voltage supplied to the X-ray tube, the current strength and the operating time of the tube. Depending on the anatomical formations being studied and the patient’s weight and dimensions, these parameters can vary significantly. There are average values ​​for different organs and tissues, but it should be borne in mind that the actual values ​​will differ depending on the machine where the examination is performed and the patient for whom the radiography is performed. An individual table of values ​​is compiled for each device. These values ​​are not absolute and are adjusted as the study progresses. The quality of the images taken largely depends on the ability of the radiographer to adequately adapt the table of average values ​​to a specific patient.

The most common way to record an X-ray image is to record it on X-ray sensitive film and then develop it. Currently, there are also systems that provide digital recording of data. Due to the high cost and complexity of manufacturing, this type of equipment is somewhat inferior to analog in terms of prevalence.

X-ray film is placed in special devices - cassettes (they say the cassette is charged). The cassette protects the film from visible light; the latter, like X-rays, has the ability to reduce metallic silver from AgBr. Cassettes are made of a material that does not transmit light, but allows x-rays to pass through. Inside the cassettes there are intensifying screens, the film is placed between them; When taking an image, not only the X-rays themselves fall on the film, but also the light from the screens (the screens are coated with fluorescent salt, so they glow and enhance the effect of the X-rays). This makes it possible to reduce the radiation dose to the patient by 10 times.

When taking an image, X-rays are directed to the center of the object being photographed (centration). After shooting in the darkroom, the film is developed in special chemicals and fixed (fixed). The fact is that on those parts of the film on which X-rays did not hit during shooting or only a small number of them hit, the silver was not restored, and if the film is not placed in a solution of a fixer (fixer), then when examining the film, the silver is restored under the influence of visible light. Sveta. The entire film will turn black and no image will be visible. When fixing (fixing), unreduced AgBr from the film goes into the fixer solution, so there is a lot of silver in the fixer, and these solutions are not poured out, but are handed over to X-ray centers.

A modern method of photographic processing of medical X-ray films is the use of roll-type developing machines. In addition to undoubted ease of use, developing machines provide high stability of the photo processing process. The time for a complete cycle from the moment the film enters the developing machine until a dry radiograph is obtained (“from dry to dry”) does not exceed several minutes.
X-ray images are an image made in black and white – a negative. Black – areas with low density (lungs, gas bubble of the stomach. White – areas with high density (bones).
Fluorography- The essence of FOG is that with it, an image of the chest is first obtained on a fluorescent screen, and then a picture is taken not of the patient himself, but of his image on the screen.

Fluorography provides a reduced image of an object. There are small-frame (for example, 24×24 mm or 35×35 mm) and large-frame (in particular, 70×70 mm or 100×100 mm) techniques. The latter approaches radiography in diagnostic capabilities. FOG is used for preventive examination of the population(hidden diseases such as cancer and tuberculosis are detected).

Both stationary and mobile fluorographic devices have been developed.

Currently, film fluorography is gradually being replaced by digital fluorography. Digital methods make it possible to simplify work with images (the image can be displayed on a monitor screen, printed, transmitted over a network, saved in a medical database, etc.), reduce radiation exposure to the patient and reduce the cost of additional materials (film, developer for films).

A conventional film chest x-ray provides the patient with an average individual radiation dose of 0.5 millisieverts (mSv) per procedure (digital x-ray - 0.05 mSv), while a film x-ray - 0.3 mSv per procedure (digital x-ray - 0 .03 mSv), and computed tomography of the chest organs - 11 mSv per procedure. Magnetic resonance imaging does not carry radiation exposure

Benefits of radiography

1. 
   Wide availability of the method and ease of research.
2. 
   Most tests do not require special patient preparation.
3. 
   Relatively low cost of research.
4. 
   The images can be used for consultation with another specialist or in another institution (unlike ultrasound images, where a repeat examination is necessary, since the resulting images are operator dependent).

1. 
   The static nature of the image makes it difficult to assess organ function.
2. 
   The presence of ionizing radiation that can have a harmful effect on the patient.
3. 
   The information content of classical radiography is significantly lower than such modern medical imaging methods as CT, MRI, etc. Conventional X-ray images reflect the projection layering of complex anatomical structures, that is, their summation X-ray shadow, in contrast to the layer-by-layer series of images obtained by modern tomographic methods.
4. 
   Without the use of contrast agents, radiography is not informative enough to analyze changes in soft tissues that differ little in density (for example, when studying the abdominal organs).

1. 
   Physical foundations of fluoroscopy. Disadvantages and advantages of the method

In modern conditions, the use of a fluorescent screen is not justified due to its low luminosity, which forces research to be carried out in a well-darkened room and after a long adaptation of the researcher to the dark (10-15 minutes) to distinguish a low-intensity image.

Now fluorescent screens are used in the design of an X-ray image intensifier (X-ray image intensifier), which increases the brightness (glow) of the primary image by approximately 5,000 times. With the help of an electron-optical converter, the image appears on the monitor screen, which significantly improves the quality of diagnosis and does not require darkening the X-ray room.

Advantages of fluoroscopy
The main advantage over radiography is the fact of research in real time. This allows you to evaluate not only the structure of the organ, but also its displacement, contractility or distensibility, passage of the contrast agent, and filling. The method also allows you to quickly assess the localization of some changes, due to the rotation of the object of study during X-ray examination (multi-projection study).

Fluoroscopy allows you to monitor the implementation of some instrumental procedures - placement of catheters, angioplasty (see angiography), fistulography.

The resulting images can be placed on a regular CD or in network storage.

With the advent of digital technologies, 3 main disadvantages inherent in traditional fluoroscopy have disappeared:

Relatively high radiation dose compared to radiography - modern low-dose devices have left this disadvantage in the past. The use of pulsed scanning modes further reduces the dose load by up to 90%.

Low spatial resolution - on modern digital devices, the resolution in the copy mode is only slightly inferior to the resolution in the radiographic mode. In this case, the ability to observe the functional state of individual organs (heart, lungs, stomach, intestines) “in dynamics” is of decisive importance.

The impossibility of documenting research - digital image processing technologies make it possible to save research materials, both frame by frame and in the form of a video sequence.

Fluoroscopy is performed mainly for X-ray diagnosis of diseases of internal organs located in the abdominal and thoracic cavities, according to the plan that the radiologist draws up before the start of the study. Sometimes, the so-called survey fluoroscopy is used to recognize traumatic bone injuries, to clarify the area to be radiographed.

Contrast fluoroscopic examination

Artificial contrast extremely expands the possibilities of fluoroscopic examination of organs and systems where tissue densities are approximately the same (for example, the abdominal cavity, the organs of which transmit X-ray radiation to approximately the same extent and are therefore low-contrast). This is achieved by introducing into the lumen of the stomach or intestines an aqueous suspension of barium sulfate, which does not dissolve in digestive juices, is not absorbed by either the stomach or intestines and is excreted naturally in a completely unchanged form. The main advantage of a barium suspension is that, passing through the esophagus, stomach and intestines, it coats their internal walls and gives on a screen or film a complete picture of the nature of the elevations, depressions and other features of their mucous membrane. The study of the internal relief of the esophagus, stomach and intestines helps to recognize a number of diseases of these organs. With tighter filling, the shape, size, position and function of the organ under study can be determined.

1. 
   Mammography - basics of the method, indications. Advantages of digital mammography over film mammography.

2.differential diagnosis between cancer and benign dyshormonal hyperplasia (FAM) of the mammary gland;

3. assessment of the growth of the primary tumor (single node or multicentric cancer foci);

4. dynamic dispensary monitoring of the condition of the mammary glands after surgical interventions.

The following methods of radiation diagnosis of breast cancer have been introduced into medical practice: mammography, ultrasound, computed tomography, magnetic resonance imaging, color and power Dopplerography, stereotactic biopsy under mammography control, thermography.

X-ray mammography
Currently, in the vast majority of cases in the world, X-ray projection mammography, film (analog) or digital, is used to diagnose female breast cancer (BC).

The procedure takes no more than 10 minutes. For the image to be taken, the breasts should be held between two straps and slightly compressed. The picture is taken in two projections so that the location of the tumor can be accurately determined if it is found. Since symmetry is one of the diagnostic factors, both breasts should always be examined.

MRI mammography

Complaints about retraction or bulging of any part of the gland

Discharge from the nipple, change in its shape

Breast tenderness, swelling, change in size

Benign breast tumors (in particular fibroadenoma)

Inflammatory processes (mastitis)

Mastopathy

Tumors of the genital organs

Diseases of the endocrine glands (thyroid, pancreas)

Infertility

Obesity

History of breast surgery

Advantages of digital mammography over film:

Reducing dose loads during X-ray examinations;

Increasing the efficiency of research, allowing to identify previously inaccessible pathological processes (the capabilities of digital computer image processing);

Possibility of using telecommunication networks to transmit images for the purpose of remote consultation;

Achieving an economic effect when conducting mass research.

Although scientists have only discovered the effect of X-rays since the 1890s, the medical use of X-rays for this natural force has progressed rapidly. Today, for the benefit of humanity, X-ray electromagnetic radiation is used in medicine, academia and industry, as well as to generate electricity.

In addition, radiation has useful applications in areas such as agriculture, archaeology, space, law enforcement, geology (including mining) and many other activities, even cars are being developed using the phenomenon of nuclear fission.

Medical uses of X-rays

In healthcare settings, physicians and dentists use a variety of nuclear materials and procedures to diagnose, monitor, and treat a wide range of metabolic processes and diseases in the human body. As a result, medical procedures using beams have saved thousands of lives by detecting and treating diseases ranging from an overactive thyroid gland to bone cancer.

The most common of these medical procedures involve the use of rays that can pass through our skin. When an image is taken, our bones and other structures appear to cast shadows because they are denser than our skin, and these shadows can be detected on film or a monitor screen. The effect is similar to placing a pencil between a piece of paper and a light. The shadow of the pencil will be visible on the piece of paper. The difference is that the rays are invisible, so a recording element is needed, something like photographic film. This allows doctors and dentists to evaluate the use of X-rays when seeing broken bones or dental problems.

The use of X-ray radiation for medicinal purposes

The use of X-ray radiation in a targeted manner for therapeutic purposes is not only for detecting damage. When used specifically, it is intended to kill cancerous tissue, reduce tumor size, or reduce pain. For example, radioactive iodine (specifically iodine-131) is often used to treat thyroid cancer, a condition that affects many people.

Devices using this property also connect to computers and scan, called: computed axial tomography or computed tomography.

These instruments provide doctors with color images that show the outline and details of internal organs. It helps doctors detect and identify tumors, size abnormalities, or other physiological or functional organ problems.
In addition, hospitals and radiology centers perform millions of procedures annually. In such procedures, doctors release slightly radioactive substances into patients' bodies to look at certain internal organs, such as the pancreas, kidneys, thyroid, liver or brain, to diagnose clinical conditions.