Modern methods of X-ray studies are classified primarily by the type of hardware visualization of X-ray projection images. That is, the main types of X-ray diagnostics are differentiated by the fact that each is based on the use of one of several existing types of X-ray detectors: X-ray film, fluorescent screen, electron-optical X-ray converter, digital detector, etc.

Classification of X-ray diagnostic methods

In modern radiology, there are general research methods and special or auxiliary ones. The practical application of these methods is possible only with the use of X-ray machines. Common methods include:

• radiography,
• fluoroscopy,
• teleradiography,
• digital radiography,
• fluorography,
• linear tomography,
• CT scan,
• contrast radiography.

Special studies include an extensive group of methods that allow solving a wide variety of diagnostic problems, and there are invasive and non-invasive methods. Invasive ones are associated with the introduction into various cavities (alimentary canal, vessels) of instruments (radio-opaque catheters, endoscopes) for carrying out diagnostic procedures under the control of x-rays. Non-invasive methods do not involve the introduction of instruments.

Each of the above methods has its own advantages and disadvantages, and hence certain limits of diagnostic capabilities. But all of them are characterized by high information content, ease of implementation, accessibility, the ability to complement each other and generally occupy one of the leading places in medical diagnostics: in more than 50% of cases, diagnosis is impossible without the use of X-ray diagnostics.

Radiography

The radiography method is the obtaining of fixed images of an object in the X-ray spectrum on a material sensitive to it (X-ray film, digital detector) according to the principle of inverse negative. The advantage of the method is a small radiation exposure, high image quality with clear detail.

The disadvantage of radiography is the impossibility of observing dynamic processes and the long processing period (in the case of film radiography). To study dynamic processes, there is a method of frame-by-frame image fixation - X-ray cinematography. It is used to study the processes of digestion, swallowing, respiration, blood circulation dynamics: X-ray phase cardiography, X-ray pneumopolygraphy.

Fluoroscopy

The method of fluoroscopy is the obtaining of an x-ray image on a fluorescent (luminescent) screen according to the direct negative principle. Allows you to study dynamic processes in real time, optimize the position of the patient in relation to the X-ray beam during the study. X-ray allows you to evaluate both the structure of the organ and its functional state: contractility or extensibility, displacement, filling with a contrast agent and its passage. The multiprojectivity of the method allows you to quickly and accurately identify the localization of existing changes.

A significant drawback of fluoroscopy is a large radiation load on the patient and the examining physician, as well as the need to conduct the procedure in a dark room.

X-ray television

Telefluoroscopy is a study that uses the conversion of an x-ray image into a television signal using an image intensifier tube or amplifier (EOP). A positive x-ray image is displayed on a TV monitor. The advantage of the technique is that it significantly eliminates the shortcomings of conventional fluoroscopy: radiation exposure to the patient and staff is reduced, image quality (contrast, brightness, high resolution, image magnification) can be controlled, the procedure is performed in a bright room.

Fluorography

The fluorography method is based on photographing a full-length shadow X-ray image from a fluorescent screen onto film. Depending on the film format, analog fluorography can be small-, medium- and large-frame (100x100 mm). It is used for mass preventive studies, mainly of the chest organs. In modern medicine, more informative large-frame fluorography or digital fluorography is used.

Contrast radiodiagnosis

Contrast X-ray diagnostics is based on the use of artificial contrasting by introducing radiopaque substances into the body. The latter are divided into X-ray positive and X-ray negative. X-ray positive substances basically contain heavy metals - iodine or barium, therefore they absorb radiation more strongly than soft tissues. X-ray negative substances are gases: oxygen, nitrous oxide, air. They absorb X-rays less than soft tissues, thereby creating a contrast with respect to the organ being examined.

Artificial contrasting is used in gastroenterology, cardiology and angiology, pulmonology, urology and gynecology, used in ENT practice and in the study of bone structures.

How an x-ray machine works

State Autonomous Professional

Educational institution of the Saratov region

"Saratov Regional Basic Medical College"

Course work

The role of the paramedic in preparing patients for X-ray methods of examination

Specialty: Medicine

Qualification: paramedic

Student:

Malkina Regina Vladimirovna

Supervisor:

Evstifeeva Tatyana Nikolaevna

Introduction………………………………………………………………… 3

Chapter 1. The history of the development of radiology as a science………………… 6

1.1. Radiology in Russia…………………………………………….. 8

1.2. X-ray methods of research……………………….. 9

Chapter 2. Preparing the patient for X-ray methods

Research…………………………………………………………….. 17

Conclusion………………………………………………………………. 21

List of used literature……………………………………... 22

Applications……………………………………………………………… 23

Introduction

Today, X-ray diagnostics is getting a new development. Using centuries of traditional radiological techniques and armed with new digital technologies, radiology continues to lead the way in diagnostic medicine.

X-ray is a time-tested and at the same time quite modern way of examining the internal organs of a patient with a high degree of information content. Radiography can be the main or one of the methods of examining a patient in order to establish the correct diagnosis or identify the initial stages of certain diseases that occur without symptoms.

The main advantages of X-ray examination are called the availability of the method and its simplicity. Indeed, in the modern world there are many institutions where you can do x-rays. It mostly does not require any special training, cheapness and the availability of images that can be consulted by several doctors in different institutions.

The disadvantages of x-rays are called obtaining a static image, radiation, in some cases, the introduction of contrast is required. The quality of images sometimes, especially on outdated equipment, does not effectively achieve the goal of the study. Therefore, it is recommended to look for an institution where to make a digital X-ray, which today is the most modern method of research and shows the highest degree of information content.

If, due to the indicated shortcomings of radiography, potential pathology is not reliably detected, additional studies may be prescribed that can visualize the work of the organ in dynamics.

X-ray methods for studying the human body are one of the most popular research methods and are used to study the structure and function of most organs and systems of our body. Despite the fact that the availability of modern methods of computed tomography is increasing every year, traditional radiography is still in great demand.

Today it is hard to imagine that medicine has been using this method for just over a hundred years. Today's doctors, "spoiled" by CT (computed tomography) and MRI (magnetic resonance imaging) find it difficult to even imagine that it is possible to work with a patient without the opportunity to "look inside" a living human body.

However, the history of the method really dates back only to 1895, when Wilhelm Conrad Roentgen first discovered the darkening of a photographic plate under the action of X-rays. In further experiments with various objects, he managed to obtain an image of the bone skeleton of the hand on a photographic plate.

This image, and then the method, became the world's first method of medical imaging. Think about it: before that, it was impossible to obtain an image of organs and tissues in vivo, without an autopsy (not invasively). The new method was a huge breakthrough in medicine and instantly spread throughout the world. In Russia, the first x-ray was taken in 1896.

Currently, radiography remains the main method for diagnosing lesions of the osteoarticular system. In addition, radiography is used in studies of the lungs, gastrointestinal tract, kidneys, etc.

aim This work is to show the role of the paramedic in preparing the patient for x-ray research methods.

A task of this work: To reveal the history of radiology, its appearance in Russia, to talk about the radiological research methods themselves, and the features of training in some of them.

Chapter 1.

Radiology, without which it is impossible to imagine modern medicine, was born thanks to the discovery by the German physicist V.K. X-ray penetrating radiation. This industry, like no other, has made an invaluable contribution to the development of medical diagnostics.

In 1894, the German physicist V. K. Roentgen (1845 - 1923) begins experimental studies of electrical discharges in glass vacuum tubes. Under the action of these discharges in conditions of highly rarefied air, rays are formed, known as cathode rays.

Studying them, Roentgen accidentally discovered the glow in the dark of a fluorescent screen (cardboard coated with barium platinum cyanide) under the action of cathode radiation emanating from a vacuum tube. To exclude the impact on the crystals of barium platinum-cyanide of visible light emanating from the included tube, the scientist wrapped it in black paper.

The glow continued, as when the scientist moved the screen almost two meters away from the tube, since it was assumed that the cathode rays penetrate only a few centimeters of air. Roentgen concluded that either he managed to obtain cathode rays with unique abilities, or he discovered the action of unknown rays.

For about two months, the scientist was engaged in the study of new rays, which he called X-rays. In the process of studying the interaction of rays with objects of different density, which Roentgen substituted along the course of radiation, he discovered the penetrating power of this radiation. Its degree depended on the density of the objects and manifested itself in the intensity of the glow of the fluorescent screen. This glow either weakened or intensified and was not observed at all when the lead plate was substituted.

In the end, the scientist put his own hand along the path of the rays and saw on the screen a bright image of the bones of the hand against the background of a weaker image of its soft tissues. To capture the shadow images of objects, Roentgen replaced the screen with a photographic plate. In particular, he received on a photographic plate an image of his own hand, which he irradiated for 20 minutes.

Roentgen was engaged in the study of X-rays from November 1895 to March 1897. During this time, the scientist published three articles with an exhaustive description of the properties of X-rays. The first article "On a new type of rays" appeared in the journal of the Würzburg Physico-Medical Society on December 28, 1895.

Thus, a change in the photographic plate under the influence of X-rays was registered, which laid the foundation for the development of future radiography.

It should be noted that many researchers were engaged in the study of cathode rays before V. Roentgen. In 1890, an X-ray image of laboratory objects was accidentally obtained in one of the American laboratories. There is evidence that Nikola Tesla was engaged in the study of bremsstrahlung and recorded the results of this study in his diary entries in 1887. In 1892, G. Hertz and his student F. Lenard, as well as the developer of the cathode ray tube V. Crooks, noted in their experiments the effect of cathode radiation on the blackening of photographic plates.

But all these researchers did not attach serious importance to the new rays, did not study them further and did not publish their observations. Therefore, the discovery of X-rays by V. Roentgen can be considered independent.

The merit of Roentgen also lies in the fact that he immediately understood the importance and significance of the rays discovered by him, developed a method for obtaining them, created the design of an x-ray tube with an aluminum cathode and a platinum anode for the production of intense x-rays.

For this discovery in 1901 W. Roentgen was awarded the Nobel Prize in Physics, the first in this category.

The revolutionary discovery of Roentgen revolutionized diagnostics. The first X-ray machines were created in Europe already in 1896. In the same year, KODAK opened the production of the first X-ray films.

Since 1912, a period of rapid development of X-ray diagnostics began throughout the world, and X-ray began to occupy an important place in medical practice.

Radiology in Russia.

The first X-ray picture in Russia was made in 1896. In the same year, at the initiative of the Russian scientist A.F. Ioffe, a student of V. Roentgen, the name "X-rays" was first introduced.

In 1918, the world's first specialized radiological clinic opened in Russia, where radiography was used to diagnose an increasing number of diseases, especially those of the lungs.

In 1921, the first X-ray dental office in Russia began its work in Petrograd. In the USSR, the government allocates the necessary funds for the development of the production of X-ray equipment, which reaches the world level in terms of quality. In 1934, the first domestic tomograph was created, and in 1935, the first fluorograph.

“Without the history of the subject, there is no theory of the subject” (N. G. Chernyshevsky). History is written not only for educational purposes. Revealing the patterns of development of X-ray radiology in the past, we gain the opportunity to build the future of this science better, more correctly, more confidently, more actively.

X-ray methods of research

All the numerous methods of X-ray examination are divided into general and special.

General methods include techniques designed to study any anatomical areas and performed on general-purpose X-ray machines (fluoroscopy and radiography).

A number of methods should also be referred to the general ones, in which it is also possible to study any anatomical regions, but either special equipment is required (fluorography, radiography with direct image magnification), or additional devices for conventional x-ray machines (tomography, electroroentgenography). Sometimes these methods are also called private.

Special techniques include those that allow you to get an image on special installations designed to study certain organs and areas (mammography, orthopantomography). Special techniques also include a large group of X-ray contrast studies, in which images are obtained using artificial contrast (bronchography, angiography, excretory urography, etc.).

General methods of X-ray examination

Fluoroscopy- a research technique in which an image of an object is obtained on a luminous (fluorescent) screen in real time. Some substances fluoresce intensely when exposed to x-rays. This fluorescence is used in X-ray diagnostics using cardboard screens coated with a fluorescent substance.

Radiography- This is a technique of X-ray examination, in which a static image of an object is obtained, fixed on any information carrier. Such carriers can be X-ray film, photographic film, digital detector, etc. An image of any anatomical region can be obtained on radiographs. Pictures of the entire anatomical region (head, chest, abdomen) are called overview. Pictures with the image of a small part of the anatomical region, which is of most interest to the doctor, are called sighting.

Fluorography- photographing an x-ray image from a fluorescent screen onto photographic film of various formats. Such an image is always scaled down.

Electroradiography is a technique in which a diagnostic image is obtained not on an x-ray film, but on the surface of a selenium plate with transfer to paper. A plate uniformly charged with static electricity is used instead of a film cassette and, depending on the different amount of ionizing radiation that has hit different points on its surface, is discharged differently. A finely dispersed coal powder is sprayed onto the surface of the plate, which, according to the laws of electrostatic attraction, is distributed unevenly over the surface of the plate. A sheet of writing paper is placed on the plate, and the image is transferred to the paper as a result of coal powder sticking. A selenium plate, unlike a film, can be used repeatedly. The technique is fast, economical, does not require a darkened room. In addition, selenium plates in an uncharged state are indifferent to the effects of ionizing radiation and can be used when working under conditions of an increased radiation background (X-ray film will become unusable under these conditions).

Special methods of X-ray examination.

Mammography- X-ray examination of the breast. It is performed to study the structure of the mammary gland when seals are found in it, as well as for a preventive purpose.

Techniques using artificial contrast:

Diagnostic pneumothorax- X-ray examination of the respiratory organs after the introduction of gas into the pleural cavity. It is performed in order to clarify the localization of pathological formations located on the border of the lung with neighboring organs. With the advent of the CT method, it is rarely used.

Pneumomediastinography- X-ray examination of the mediastinum after the introduction of gas into its tissue. It is performed in order to clarify the localization of pathological formations (tumors, cysts) identified in the images and their spread to neighboring organs. With the advent of the CT method, it is practically not used.

Diagnostic pneumoperitoneum- X-ray examination of the diaphragm and organs of the abdominal cavity after the introduction of gas into the peritoneal cavity. It is performed in order to clarify the localization of pathological formations identified in the images against the background of the diaphragm.

pneumoretroperitoneum- a technique for X-ray examination of organs located in the retroperitoneal tissue by introducing gas into the retroperitoneal tissue in order to better visualize their contours. With the introduction of ultrasound, CT and MRI into clinical practice, it is practically not used.

Pneumoren- X-ray examination of the kidney and adjacent adrenal gland after the introduction of gas into the perirenal tissue. Currently, it is extremely rare.

Pneumopyelography- study of the cavitary system of the kidney after filling it with gas through the ureteral catheter. It is currently used mainly in specialized hospitals for the detection of intrapelvic tumors.

Pneumomyelography- X-ray examination of the subarachnoid space of the spinal cord after gas contrasting. It is used to diagnose pathological processes in the area of ​​the spinal canal, causing narrowing of its lumen (herniated discs, tumors). Rarely used.

Pneumoencephalography- X-ray examination of the cerebrospinal fluid spaces of the brain after contrasting with gas. Once introduced into clinical practice, CT and MRI are rarely performed.

Pneumoarthrography- X-ray examination of large joints after the introduction of gas into their cavity. Allows you to study the articular cavity, identify intra-articular bodies in it, detect signs of damage to the menisci of the knee joint. Sometimes it is supplemented by the introduction into the joint cavity

water-soluble RCS. It is widely used in medical institutions when it is impossible to perform MRI.

Bronchography- a technique for X-ray examination of the bronchi after their artificial contrasting of the RCS. Allows you to identify various pathological changes in the bronchi. It is widely used in medical institutions when CT is not available.

Pleurography- X-ray examination of the pleural cavity after its partial filling with a contrast agent in order to clarify the shape and size of pleural encystation.

Sinography- X-ray examination of the paranasal sinuses after their filling with the RCS. It is used when there are difficulties in interpreting the cause of shading of the sinuses on radiographs.

Dacryocystography- X-ray examination of the lacrimal ducts after their filling with the RCS. It is used to study the morphological state of the lacrimal sac and the patency of the lacrimal canal.

Sialography- X-ray examination of the ducts of the salivary glands after their filling with the RCS. It is used to assess the condition of the ducts of the salivary glands.

X-ray of the esophagus, stomach and duodenum- is carried out after their gradual filling with a suspension of barium sulfate, and, if necessary, with air. It necessarily includes polypositional fluoroscopy and the performance of survey and sighting radiographs. It is widely used in medical institutions to detect various diseases of the esophagus, stomach and duodenum (inflammatory and destructive changes, tumors, etc.) (see Fig. 2.14).

Enterography- X-ray examination of the small intestine after filling its loops with a suspension of barium sulfate. Allows you to get information about the morphological and functional state of the small intestine (see Fig. 2.15).

Irrigoscopy- X-ray examination of the colon after retrograde contrasting of its lumen with a suspension of barium sulfate and air. It is widely used to diagnose many diseases of the colon (tumors, chronic colitis, etc.) (see Fig. 2.16).

Cholecystography- X-ray examination of the gallbladder after the accumulation of a contrast agent in it, taken orally and excreted with bile.

Excretory cholegraphy- X-ray examination of the biliary tract, contrasted with iodine-containing drugs administered intravenously and excreted in the bile.

Cholangiography- X-ray examination of the bile ducts after the introduction of the RCS into their lumen. It is widely used to clarify the morphological state of the bile ducts and to identify stones in them. It can be performed during surgery (intraoperative cholangiography) and in the postoperative period (through a drainage tube).

Retrograde cholangiopancreaticography- X-ray examination of the bile ducts and pancreatic duct after the introduction of a contrast agent into their lumen under X-ray endoscopic co. Excretory urography - X-ray examination of the urinary organs after intravenous administration of RCS and its excretion by the kidneys. A widely used research technique that allows you to study the morphological and functional state of the kidneys, ureters and bladder.

Retrograde ureteropyelography- X-ray examination of the ureters and cavitary systems of the kidneys after filling them with RCS through a ureteral catheter. Compared to excretory urography, it allows to obtain more complete information about the state of the urinary tract as a result of their better filling with a contrast agent injected under low pressure. Widely used in specialized urological departments.

Cystography- X-ray examination of the bladder filled with RCS.

urethrography- X-ray examination of the urethra after its filling with the RCS. Allows you to get information about the patency and morphological state of the urethra, identify its damage, strictures, etc. It is used in specialized urological departments.

Hysterosalpingography- X-ray examination of the uterus and fallopian tubes after filling their lumen with the RCS. It is widely used primarily to assess the patency of the fallopian tubes.

Positive myelography- X-ray examination of the subarachnoid spaces of the spinal cord after the introduction of water-soluble RCS. With the advent of MRI, it is rarely used.

Aortography- X-ray examination of the aorta after the introduction of the RCS into its lumen.

Arteriography- X-ray examination of the arteries with the help of RCS introduced into their lumen, spreading through the blood flow. Some private methods of arteriography (coronary angiography, carotid angiography), being highly informative, are at the same time technically complex and unsafe for the patient, and therefore are used only in specialized departments.

Cardiography- X-ray examination of the cavities of the heart after the introduction of the RCS into them. Currently, it finds limited use in specialized cardiac surgical hospitals.

Angiopulmonography- X-ray examination of the pulmonary artery and its branches after the introduction of RCS into them. Despite the high information content, it is unsafe for the patient, and therefore, in recent years, preference has been given to computed tomographic angiography.

Phlebography- X-ray examination of the veins after the introduction of the RCS into their lumen.

Lymphography- X-ray examination of the lymphatic tract after the introduction of the RCS into the lymphatic channel.

Fistulography- X-ray examination of the fistulous tracts after their filling by the RCS.

Vulnerography- X-ray examination of the wound channel after filling it with RCS. It is more often used for blind wounds of the abdomen, when other research methods do not allow to establish whether the wound is penetrating or non-penetrating.

Cystography- contrast x-ray examination of cysts of various organs in order to clarify the shape and size of the cyst, its topographic location and the state of the inner surface.

Ductography- contrast x-ray examination of the milk ducts. Allows you to assess the morphological state of the ducts and identify small breast tumors with intraductal growth, indistinguishable on mammograms.

Chapter 2

General rules for patient preparation:

1.Psychological preparation. The patient must understand the importance of the upcoming study, must be confident in the safety of the upcoming study.

2.Before conducting the study, care must be taken to make the organ more accessible during the study. Before endoscopic examinations, it is necessary to free the organ under study from the contents. The organs of the digestive system are examined on an empty stomach: on the day of the study, you can not drink, eat, take medicine, brush your teeth, or smoke. On the eve of the upcoming study, a light dinner is allowed, no later than 19.00. Before examining the intestines, a slag-free diet (No. 4) is prescribed for 3 days, drugs to reduce gas formation (activated charcoal) and improve digestion (enzyme preparations), laxatives; enemas on the eve of the study. According to the special prescription of the doctor, premedication is carried out (the introduction of atropine and painkillers). Cleansing enemas are given no later than 2 hours before the upcoming study, as the relief of the intestinal mucosa changes.

R-scopy of the stomach:

1. 3 days before the study, foods that cause gas formation are excluded from the patient's diet (diet 4)

2. In the evening, no later than 17:00, a light dinner: cottage cheese, egg, jelly, semolina.

3. The study is carried out strictly on an empty stomach (do not drink, do not eat, do not smoke, do not brush your teeth).

Irrigoscopy:

1. 3 days before the study, exclude from the patient's diet foods that cause gas formation (legumes, fruits, vegetables, juices, milk).

2. If the patient is concerned about flatulence, activated charcoal is prescribed for 3 days 2-3 times a day.

3. The day before the study, before dinner, give the patient 30.0 castor oil.

4. The night before, a light dinner no later than 17:00.

5. At 21 and 22 o'clock in the evening on the eve of doing cleansing enemas.

6. In the morning on the day of the study at 6 and 7 o'clock cleansing enemas.

7. A light breakfast is allowed.

8. For 40min. – 1 hour before the study, insert the gas outlet tube for 30 minutes.

Cholecystography:

1. Within 3 days, products that cause flatulence are excluded.

2. On the eve of the study, a light dinner no later than 17 hours.

3. From 21.00 to 22.00 hours the day before, the patient uses a contrast agent (billitrast) according to the instructions depending on body weight.

4. Research is carried out on an empty stomach.

5. The patient is warned that loose stools and nausea may occur.

6. In the R - office, the patient should bring 2 raw eggs with him for a choleretic breakfast.

Intravenous cholegraphy:

1. 3 days of dieting with the exclusion of gas-producing foods.

2. Find out if the patient is allergic to iodine (runny nose, rash, skin itching, vomiting). Notify doctor.

3. Carry out a test 24 hours before the study, for which in/in enter 1-2 ml of bilignost per 10 ml of saline.

4. The day before the study, choleretic drugs are canceled.

5. In the evening at 21 and 22 hours, a cleansing enema and in the morning on the day of the study, 2 hours before, a cleansing enema.

6. The study is carried out on an empty stomach.

Urography:

1. 3 days slag-free diet (No. 4)

2. A day before the study, a test for sensitivity to a contrast agent is carried out.

3. On the evening before at 21.00 and 22.00 cleansing enemas. In the morning at 6.00 and 7.00 cleansing enemas.

4. The study is carried out on an empty stomach, before the study, the patient empties the bladder.

Radiography:

1. It is necessary to free the area under study from clothing as much as possible.

2. The examination area must also be free of dressings, plasters, electrodes, and other foreign objects that may reduce the quality of the resulting image.

3. Make sure that there are no various chains, watches, belts, hairpins, if they are located in the area that will be examined.

4. Only the area of ​​interest to the doctor is left open, the rest of the body is covered with a special protective apron that shields x-rays.

Conclusion.

Thus, at present, radiological research methods have found wide diagnostic use, and have become an integral part of the clinical examination of patients. Also, an integral part is the preparation of the patient for x-ray methods of research, because each of them has its own characteristics, if not performed, it can lead to difficulty in making a diagnosis.

One of the main parts of preparing a patient for X-ray methods of research is psychological preparation. The patient must understand the importance of the upcoming study, must be confident in the safety of the upcoming study. After all, the patient has the right to refuse this study, which will greatly complicate the diagnosis.

Literature

Antonovich V.B. "X-ray diagnostics of diseases of the esophagus, stomach, intestines". - M., 1987.

Medical radiology. - Lindenbraten L.D., Naumov L.B. - 2014;

Medical Radiology (Fundamentals of Radiation Diagnostics and Radiation Therapy) - Lindenbraten L.D., Korolyuk I.P. - 2012;

Fundamentals of medical X-ray technology and methods of X-ray examination in clinical practice / Koval G.Yu., Sizov V.A., Zagorodskaya M.M. and etc.; Ed. G. Yu. Koval.-- K .: Health, 2016.

Pytel A.Ya., Pytel Yu.A. "X-ray diagnostics of urological diseases" - M., 2012.

Radiology: Atlas / ed. A. Yu. Vasil'eva. - M. : GEOTAR-Media, 2013.

Rutsky A.V., Mikhailov A.N. "X-ray diagnostic atlas". - Minsk. 2016.

Sivash E.S., Salman M.M. "Possibilities of X-ray method", Moscow, Ed. "Science", 2015

Fanarjyan V.A. "X-ray diagnostics of diseases of the digestive tract". – Yerevan, 2012.

Shcherbatenko M.K., Beresneva Z.A. "Urgent X-ray diagnostics of acute diseases and injuries of the abdominal organs". - M., 2013.

Applications

Figure 1.1 Fluoroscopy procedure.

Figure 1.2. Carrying out radiography.

Figure 1.3. Chest X-ray.

Figure 1.4. Conducting fluorography.

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Radiology as a science dates back to November 8, 1895, when the German physicist Professor Wilhelm Conrad Roentgen discovered rays, later named after him. Roentgen himself called them X-rays. This name has been preserved in his homeland and in Western countries.

Basic properties of X-rays:

X-rays, proceeding from the focus of the X-ray tube, propagate in a straight line.

They do not deviate in an electromagnetic field.

Their propagation speed is equal to the speed of light.

X-rays are invisible, but when absorbed by certain substances, they cause them to glow. This glow is called fluorescence and is the basis of fluoroscopy.

X-rays have a photochemical effect. This property of X-rays is the basis of radiography (the currently generally accepted method for producing X-ray images).

X-ray radiation has an ionizing effect and gives the air the ability to conduct electricity. Neither visible, nor thermal, nor radio waves can cause this phenomenon. Based on this property, X-rays, like the radiation of radioactive substances, are called ionizing radiation.

An important property of X-rays is their penetrating power, i.e. the ability to pass through the body and objects. The penetrating power of X-rays depends on:

From the quality of the rays. The shorter the length of the X-rays (i.e., the harder the X-rays), the deeper these rays penetrate and, conversely, the longer the wavelength of the rays (the softer the radiation), the shallower they penetrate.

From the volume of the body under study: the thicker the object, the more difficult it is for X-rays to “penetrate” it. The penetrating power of X-rays depends on the chemical composition and structure of the body under study. The more atoms of elements with high atomic weight and serial number (according to the periodic table) in a substance exposed to X-rays, the stronger it absorbs X-rays and, conversely, the lower the atomic weight, the more transparent the substance for these rays. The explanation for this phenomenon is that in electromagnetic radiation with a very short wavelength, which are X-rays, a lot of energy is concentrated.

X-rays have an active biological effect. In this case, DNA and cell membranes are critical structures.

One more circumstance must be taken into account. X-rays obey the inverse square law, i.e. The intensity of X-rays is inversely proportional to the square of the distance.

Gamma rays have the same properties, but these types of radiation differ in the way they are produced: X-rays are obtained in high-voltage electrical installations, and gamma radiation is due to the decay of atomic nuclei.

Methods of X-ray examination are divided into basic and special, private.

Basic X-ray methods: radiography, fluoroscopy, computed x-ray tomography.

Radiography and fluoroscopy are performed on x-ray machines. Their main elements are a feeder, an emitter (X-ray tube), devices for the formation of X-rays and radiation receivers. X-ray machine

powered by the city's AC network. The power supply increases the voltage to 40-150 kV and reduces the ripple, in some devices the current is almost constant. The quality of X-ray radiation, in particular, its penetrating power, depends on the magnitude of the voltage. As the voltage increases, the radiation energy increases. This reduces the wavelength and increases the penetrating power of the resulting radiation.

An X-ray tube is an electrovacuum device that converts electrical energy into X-ray energy. An important element of the tube are the cathode and anode.

When a low voltage current is applied to the cathode, the filament heats up and begins to emit free electrons (electron emission), forming an electron cloud around the filament. When the high voltage is turned on, the electrons emitted by the cathode are accelerated in the electric field between the cathode and the anode, fly from the cathode to the anode and, hitting the anode surface, are decelerated, releasing X-ray quanta. Screening gratings are used to reduce the effect of scattered radiation on the information content of radiographs.

X-ray receivers are X-ray film, fluorescent screen, digital radiography systems, and in CT, dosimetric detectors.

Radiography- X-ray examination, in which an image of the object under study is obtained, fixed on a photosensitive material. When taking X-rays, the object to be photographed must be in close contact with the cassette loaded with film. X-ray radiation coming out of the tube is directed perpendicularly to the center of the film through the middle of the object (the distance between the focus and the patient's skin under normal operating conditions is 60-100 cm). Indispensable equipment for radiography are cassettes with intensifying screens, screening grids and a special x-ray film. Special movable gratings are used to filter out soft x-rays that can reach the film, as well as secondary radiation. The cassettes are made of opaque material and correspond in size to the standard sizes of produced X-ray film (13 × 18 cm, 18 × 24 cm, 24 × 30 cm, 30 × 40 cm, etc.).

X-ray film is usually coated on both sides with a photographic emulsion. The emulsion contains silver bromide crystals that are ionized by x-ray and visible light photons. The X-ray film is in an opaque cassette along with X-ray intensifying screens (REI). REU is a flat base on which a layer of X-ray phosphor is applied. X-ray film is affected by X-rays not only by X-rays, but also by light from the REU. Intensifying screens are designed to increase the light effect of x-rays on photographic film. Currently, screens with phosphors activated by rare earth elements are widely used: lanthanum oxide bromide and gadolinium oxide sulfite. The good efficiency of the rare earth phosphor contributes to the high light sensitivity of the screens and ensures high image quality. There are also special screens - Gradual, which can even out the existing differences in the thickness and (or) density of the subject. The use of intensifying screens significantly reduces the exposure time for radiography.

The blackening of the x-ray film occurs due to the reduction of metallic silver under the action of x-rays and light in its emulsion layer. The number of silver ions depends on the number of photons acting on the film: the greater their number, the greater the number of silver ions. The changing density of silver ions forms an image hidden inside the emulsion, which becomes visible after special processing by the developer. Processing of the filmed films is carried out in a photo laboratory. The processing process is reduced to developing, fixing, washing the film, followed by drying. During the development of the film, black metallic silver is deposited. Non-ionized silver bromide crystals remain unchanged and invisible. The fixer removes the silver bromide crystals, leaving metallic silver. After fixing, the film is insensitive to light. Drying of films is carried out in drying cabinets, which takes at least 15 minutes, or occurs naturally, while the picture is ready the next day. When using processing machines, images are obtained immediately after the study. The image on x-ray film is due to varying degrees of blackening caused by changes in the density of the black silver granules. The darkest areas on x-ray film correspond to the highest radiation intensity, so the image is called negative. White (light) areas on radiographs are called dark (blackouts), and black areas are light (enlightenment) (Fig. 1.2).

Benefits of radiography:

An important advantage of radiography is its high spatial resolution. According to this indicator, no visualization method can be compared with it.

The dose of ionizing radiation is lower than with fluoroscopy and x-ray computed tomography.

Radiography can be performed both in the X-ray room, and directly in the operating room, dressing room, plaster cast, or even in the ward (using mobile X-ray units).

An x-ray is a document that can be stored for a long time. It can be studied by many experts.

Disadvantage of radiography: the study is static, there is no possibility of assessing the movement of objects during the study.

Digital radiography includes ray pattern detection, image processing and recording, image presentation and viewing, information storage. In digital radiography, analog information is converted into digital form using analog-to-digital converters, the reverse process occurs using digital-to-analog converters. To display an image, a digital matrix (numerical rows and columns) is transformed into a matrix of visible image elements - pixels. A pixel is the smallest element of a picture reproduced by an imaging system. Each pixel, in accordance with the value of the digital matrix, is assigned one of the shades of the gray scale. The number of possible gray scale shades between black and white is often specified on a binary basis, eg 10 bits = 2 10 or 1024 shades.

Currently, four digital radiography systems have been technically implemented and have already received clinical use:

− digital radiography from the screen of the electron-optical converter (EOC);

− digital fluorescent radiography;

− scanning digital radiography;

− digital selenium radiography.

The system of digital radiography from the image intensifier tube consists of an image intensifier tube, a television path and an analog-to-digital converter. The image intensifier tube is used as an image detector. The television camera converts the optical image on the image intensifier tube into an analog video signal, which is then formed into a digital data set using an analog-to-digital converter and transferred to a storage device. Then the computer translates this data into a visible image on the monitor screen. The image is studied on the monitor and can be printed on film.

In digital fluorescent radiography, after exposure to X-rays, luminescent memory plates are scanned by a special laser device, and the light beam that occurs during laser scanning is transformed into a digital signal that reproduces an image on a monitor screen that can be printed. Luminescent plates are built into cassettes that are reusable (from 10,000 to 35,000 times) with any X-ray machine.

In scanning digital radiography, a moving narrow beam of X-ray radiation is sequentially passed through all departments of the object under study, which is then recorded by a detector and, after digitization in an analog-to-digital converter, is transmitted to a computer monitor screen with a possible subsequent printout.

Digital selenium radiography uses a selenium-coated detector as an X-ray receiver. The latent image formed in the selenium layer after exposure in the form of areas with different electric charges is read using scanning electrodes and transformed into a digital form. Further, the image can be viewed on the monitor screen or printed on film.

Benefits of digital radiography:

reduction of dose loads on patients and medical personnel;

cost-effectiveness in operation (during shooting, an image is immediately obtained, there is no need to use x-ray film, other consumables);

high performance (about 120 images per hour);

digital image processing improves the quality of the image and thereby increases the diagnostic information content of digital radiography;

cheap digital archiving;

fast search of the x-ray image in computer memory;

reproduction of the image without loss of its quality;

the possibility of combining various equipment of the radiology department into a single network;

the possibility of integration into the general local network of the institution (“electronic medical record”);

the possibility of organizing remote consultations (“telemedicine”).

Image quality when using digital systems can be characterized, as with other ray methods, by such physical parameters as spatial resolution and contrast. Shadow contrast is the difference in optical density between adjacent areas of the image. Spatial resolution is the minimum distance between two objects at which they can still be separated from one another in an image. Digitization and image processing lead to additional diagnostic possibilities. Thus, a significant distinguishing feature of digital radiography is a greater dynamic range. That is, x-rays with a digital detector will be of good quality over a larger range of x-ray doses than with conventional x-rays. The ability to freely adjust image contrast in digital processing is also a significant difference between conventional and digital radiography. Contrast transfer is thus not limited by the choice of image receiver and exam parameters, and can be further adapted to solve diagnostic problems.

Fluoroscopy- transillumination of organs and systems using X-rays. Fluoroscopy is an anatomical and functional method that provides an opportunity to study the normal and pathological processes of organs and systems, as well as tissues by the shadow pattern of a fluorescent screen. The study is performed in real time, i.e. the production of the image and its acquisition by the researcher coincide in time. On fluoroscopy, a positive image is obtained. Light areas visible on the screen are called light, and dark areas are called dark.

Benefits of fluoroscopy:

allows you to examine patients in various projections and positions, due to which you can choose a position in which a pathological formation is better detected;

the possibility of studying the functional state of a number of internal organs: lungs, at various phases of respiration; pulsation of the heart with large vessels, motor function of the digestive canal;

close contact between the radiologist and the patient, which makes it possible to supplement the X-ray examination with the clinical one (palpation under visual control, targeted history), etc.;

the possibility of performing manipulations (biopsies, catheterizations, etc.) under the control of an x-ray image.

Flaws:

relatively large radiation exposure to the patient and attendants;

low throughput during the doctor's working hours;

limited capabilities of the researcher's eye in identifying small shadow formations and fine tissue structures; Indications for fluoroscopy are limited.

Electron-optical amplification (EOA). It is based on the principle of converting an X-ray image into an electronic image, followed by its transformation into an enhanced light image. An X-ray image intensifier tube is a vacuum tube (Fig. 1.3). X-rays carrying the image from the translucent object fall on the input fluorescent screen, where their energy is converted into light energy of the input luminescent screen. Next, the photons emitted by the luminescent screen fall on the photocathode, which converts light radiation into a stream of electrons. Under the influence of a constant electric field of high voltage (up to 25 kV) and as a result of focusing by electrodes and an anode of a special shape, the energy of electrons increases several thousand times and they are directed to the output luminescent screen. The brightness of the output screen is amplified up to 7,000 times compared to the input screen. The image from the output fluorescent screen is transmitted to the display screen by means of a television tube. The use of an EOS makes it possible to distinguish details with a size of 0.5 mm, i.e. 5 times smaller than with conventional fluoroscopic examination. When using this method, X-ray cinematography can be used, i.e. recording an image on film or videotape and digitizing the image using an analog-to-digital converter.

Rice. 1.3. EOP scheme. 1 − x-ray tube; 2 - object; 3 - input luminescent screen; 4 - focusing electrodes; 5 - anode; 6 − output luminescent screen; 7 - outer shell. The dotted lines indicate the electron flow.

X-ray computed tomography (CT). The creation of X-ray computed tomography was the most important event in radiation diagnostics. Evidence of this is the award of the Nobel Prize in 1979 to the famous scientists Cormac (USA) and Hounsfield (England) for the creation and clinical testing of CT.

CT allows you to study the position, shape, size and structure of various organs, as well as their relationship with other organs and tissues. Advances achieved with the help of CT in the diagnosis of various diseases served as a stimulus for the rapid technical improvement of devices and a significant increase in their models.

CT is based on the registration of X-ray radiation with sensitive dosimetric detectors and the creation of an X-ray image of organs and tissues using a computer. The principle of the method is that after the rays pass through the patient's body, they do not fall on the screen, but on the detectors, in which electrical impulses arise, which are transmitted after amplification to the computer, where they are reconstructed according to a special algorithm and create an image of the object studied on the monitor ( Fig. 1.4).

The image of organs and tissues on CT, unlike traditional x-rays, is obtained in the form of transverse sections (axial scans). On the basis of axial scans, an image reconstruction is obtained in other planes.

Three types of computed tomography scanners are currently used in radiology practice: conventional step, spiral or screw, multislice.

In conventional stepping CT scanners, high voltage is supplied to the X-ray tube through high-voltage cables. Because of this, the tube cannot rotate constantly, but must perform a rocking motion: one turn clockwise, stop, one turn counterclockwise, stop and back. As a result of each rotation, one image with a thickness of 1 - 10 mm is obtained in 1 - 5 seconds. In the interval between slices, the tomograph table with the patient moves to a set distance of 2–10 mm, and the measurements are repeated. With a slice thickness of 1 - 2 mm, stepping devices allow you to perform research in the "high resolution" mode. But these devices have a number of disadvantages. Scan times are relatively long and motion and breath artifacts may appear on images. Image reconstruction in projections other than axial ones is difficult or simply impossible. There are serious limitations when performing dynamic scanning and studies with contrast enhancement. In addition, small formations between sections may not be detected if the patient's breathing is uneven.

In spiral (screw) computed tomographs, the constant rotation of the tube is combined with the simultaneous movement of the patient table. Thus, during the study, information is obtained immediately from the entire volume of tissues under study (the entire head, chest), and not from individual sections. With spiral CT, a three-dimensional image reconstruction (3D mode) with high spatial resolution is possible, including virtual endoscopy, which allows visualizing the inner surface of the bronchi, stomach, colon, larynx, paranasal sinuses. Unlike endoscopy with fiber optics, the narrowing of the lumen of the object under study is not an obstacle to virtual endoscopy. But in the conditions of the latter, the color of the mucous membrane differs from the natural one and it is impossible to perform a biopsy (Fig. 1.5).

Stepping and spiral tomographs use one or two rows of detectors. Multislice (multi-detector) CT scanners are equipped with 4, 8, 16, 32 and even 128 rows of detectors. In multislice devices, the scan time is significantly reduced and the spatial resolution in the axial direction is improved. They can obtain information using a high-resolution technique. The quality of multiplanar and volumetric reconstructions is significantly improved. CT has several advantages over conventional x-rays:

First of all, high sensitivity, which makes it possible to differentiate individual organs and tissues from each other in terms of density up to 0.5%; on conventional radiographs, this figure is 10-20%.

CT makes it possible to obtain an image of organs and pathological foci only in the plane of the examined section, which gives a clear image without layering of formations lying above and below.

CT makes it possible to obtain accurate quantitative information about the size and density of individual organs, tissues and pathological formations.

CT makes it possible to judge not only the state of the organ under study, but also the relationship of the pathological process with surrounding organs and tissues, for example, tumor invasion into neighboring organs, the presence of other pathological changes.

CT allows you to get topograms, i.e. a longitudinal image of the area under study, like an x-ray, by moving the patient along a fixed tube. Topograms are used to establish the extent of the pathological focus and determine the number of sections.

With helical CT under 3D reconstruction, virtual endoscopy can be performed.

CT is indispensable for radiotherapy planning (radiation mapping and dose calculation).

CT data can be used for diagnostic puncture, which can be successfully used not only to detect pathological changes, but also to assess the effectiveness of treatment and, in particular, antitumor therapy, as well as to determine relapses and associated complications.

Diagnosis by CT is based on direct radiographic features, i.e. determining the exact localization, shape, size of individual organs and the pathological focus and, most importantly, on indicators of density or absorption. The absorbance index is based on the degree to which an X-ray beam is absorbed or attenuated as it passes through the human body. Each tissue, depending on the density of the atomic mass, absorbs radiation differently, therefore, at present, for each tissue and organ, the absorption coefficient (KA), denoted in Hounsfield units (HU), is normally developed. HUwater is taken as 0; bones with the highest density - for +1000, air, which has the lowest density - for - 1000.

With CT, the entire gray scale range, in which the image of tomograms on the video monitor screen is presented, is from - 1024 (black level) to + 1024 HU (white level). Thus, with a CT "window", that is, the range of changes in HU (Hounsfield units) is measured from - 1024 to + 1024 HU. For visual analysis of information in the gray scale, it is necessary to limit the "window" of the scale according to the image of tissues with similar density values. By successively changing the size of the "window", it is possible to study different density areas of the object under optimal visualization conditions. For example, for optimal lung evaluation, a black level is chosen close to the average lung density (between -600 and -900 HU). By a “window” with a width of 800 with a level of -600 HU, it is meant that densities - 1000 HU are seen as black, and all densities - 200 HU and above - as white. If the same image is used to assess the details of the bony structures of the chest, a 1000 wide window at +500 HU will produce a full gray scale between 0 and +1000 HU. The image during CT is studied on the monitor screen, placed in the long-term memory of the computer or obtained on a solid carrier - photographic film. Light areas on a CT scan (when viewed in black and white) are called “hyperdense”, and dark areas are called “hypodense”. Density means the density of the structure under study (Fig. 1.6).

The minimum size of a tumor or other pathological focus, determined by CT, ranges from 0.5 to 1 cm, provided that the HU of the affected tissue differs from that of the healthy one by 10-15 units.

The disadvantage of CT is the increased radiation exposure to patients. Currently, CT accounts for 40% of the total radiation dose received by patients during radiological procedures, while CT examinations account for only 4% of all radiological examinations.

In both CT and X-ray examinations, it becomes necessary to use the “image enhancement” technique to increase the resolution. Contrast in CT is performed with water-soluble radiopaque agents.

The “enhancement” technique is carried out by perfusion or infusion administration of a contrast agent.

X-ray examination methods are called special if artificial contrast is used. The organs and tissues of the human body become visible if they absorb x-rays to varying degrees. Under physiological conditions, such differentiation is possible only in the presence of natural contrast, which is determined by the difference in density (the chemical composition of these organs), size, and position. The bone structure is well detected against the background of soft tissues, the heart and large vessels against the background of airy lung tissue, however, under conditions of natural contrast, the chambers of the heart cannot be distinguished separately, as, for example, the organs of the abdominal cavity. The need to study organs and systems with the same density by X-rays led to the creation of a technique for artificial contrasting. The essence of this technique is the introduction of artificial contrast agents into the organ under study, i.e. substances having a density that differs from the density of the organ and its environment (Fig. 1.7).

Radiocontrast media (RCS) It is customary to subdivide into substances with a high atomic weight (X-ray positive contrast agents) and low (X-ray negative contrast agents). The contrast agents must be harmless.

Contrast agents that absorb intensely x-rays (positive radiopaque agents) are:

Suspensions of salts of heavy metals - barium sulfate, used to study the gastrointestinal tract (it is not absorbed and excreted through natural routes).

Aqueous solutions of organic compounds of iodine - urographin, verografin, bilignost, angiographin, etc., which are introduced into the vascular bed, enter all organs with the blood flow and give, in addition to contrasting the vascular bed, contrasting other systems - urinary, gallbladder, etc. .

Oily solutions of organic iodine compounds - yodolipol, etc., which are injected into fistulas and lymphatic vessels.

Non-ionic water-soluble iodine-containing radiopaque agents: ultravist, omnipak, imagopak, vizipak are characterized by the absence of ionic groups in the chemical structure, low osmolarity, which significantly reduces the possibility of pathophysiological reactions, and thereby causes a low number of side effects. Non-ionic iodine-containing radiopaque agents cause a lower number of side effects than ionic high-osmolar contrast media.

X-ray negative, or negative contrast agents - air, gases "do not absorb" x-rays and therefore shade well the organs and tissues under study, which have a high density.

Artificial contrasting according to the method of administration of contrast agents is divided into:

The introduction of contrast agents into the cavity of the organs under study (the largest group). This includes studies of the gastrointestinal tract, bronchography, fistula studies, all types of angiography.

The introduction of contrast agents around the studied organs - retropneumoperitoneum, pneumothorax, pneumomediastinography.

The introduction of contrast agents into the cavity and around the studied organs. This group includes parietography. Parietography in diseases of the gastrointestinal tract consists in obtaining images of the wall of the investigated hollow organ after the introduction of gas, first around the organ, and then into the cavity of this organ.

A method based on the specific ability of some organs to concentrate individual contrast agents and at the same time shade them against the background of surrounding tissues. These include excretory urography, cholecystography.

Side effects of RCS. Body reactions to the introduction of RCS are observed in approximately 10% of cases. By nature and severity, they are divided into 3 groups:

Complications associated with the manifestation of a toxic effect on various organs with functional and morphological lesions.

The neurovascular reaction is accompanied by subjective sensations (nausea, feeling of heat, general weakness). Objective symptoms in this case are vomiting, lowering blood pressure.

Individual intolerance to RCS with characteristic symptoms:

1. From the side of the central nervous system - headaches, dizziness, agitation, anxiety, fear, the occurrence of convulsive seizures, cerebral edema.

   Skin reactions - hives, eczema, itching, etc.

   Symptoms associated with impaired activity of the cardiovascular system - pallor of the skin, discomfort in the region of the heart, drop in blood pressure, paroxysmal tachycardia or bradycardia, collapse.

   Symptoms associated with respiratory failure - tachypnea, dyspnea, asthma attack, laryngeal edema, pulmonary edema.

RCS intolerance reactions are sometimes irreversible and fatal.

The mechanisms of development of systemic reactions in all cases are similar in nature and are due to the activation of the complement system under the influence of RCS, the effect of RCS on the blood coagulation system, the release of histamine and other biologically active substances, a true immune response, or a combination of these processes.

In mild cases of adverse reactions, it is enough to stop the injection of RCS and all phenomena, as a rule, disappear without therapy.

With the development of severe adverse reactions, primary emergency care should begin at the place of production of the study by employees of the x-ray room. First of all, it is necessary to immediately stop the intravenous administration of the radiopaque drug, call a doctor whose duties include providing emergency medical care, establish reliable access to the venous system, ensure airway patency, for which you need to turn the patient’s head to the side and fix the tongue, and also ensure the possibility of carrying out (if necessary) inhalation of oxygen at a rate of 5 l / min. When anaphylactic symptoms appear, the following urgent anti-shock measures should be taken:

- inject intramuscularly 0.5-1.0 ml of a 0.1% solution of adrenaline hydrochloride;

- in the absence of a clinical effect with preservation of severe hypotension (below 70 mm Hg), start intravenous infusion at a rate of 10 ml / h (15-20 drops per minute) of a mixture of 5 ml of a 0.1% solution of adrenaline hydrochloride diluted in 400 ml of 0.9% sodium chloride solution. If necessary, the infusion rate can be increased to 85 ml / h;

- in case of a serious condition of the patient, additionally intravenously inject one of the glucocorticoid preparations (methylprednisolone 150 mg, dexamethasone 8-20 mg, hydrocortisone hemisuccinate 200-400 mg) and one of the antihistamines (diphenhydramine 1% -2.0 ml, suprastin 2% -2 .0 ml, tavegil 0.1% -2.0 ml). The introduction of pipolfen (diprazine) is contraindicated due to the possibility of developing hypotension;

- in case of adrenaline-resistant bronchospasm and an attack of bronchial asthma, slowly inject 10.0 ml of a 2.4% solution of aminophylline intravenously. If there is no effect, re-introduce the same dose of aminophylline.

In case of clinical death, carry out mouth-to-mouth artificial respiration and chest compressions.

All anti-shock measures should be carried out as quickly as possible until the blood pressure normalizes and the patient's consciousness is restored.

With the development of moderate vasoactive adverse reactions without significant respiratory and circulatory disorders, as well as with skin manifestations, emergency care may be limited to the introduction of only antihistamines and glucocorticoids.

In case of laryngeal edema, along with these drugs, 0.5 ml of a 0.1% solution of adrenaline and 40-80 mg of lasix should be administered intravenously, as well as humidified oxygen inhalation. After the implementation of mandatory anti-shock therapy, regardless of the severity of the condition, the patient must be hospitalized to continue intensive care and rehabilitation treatment.

Due to the possibility of developing adverse reactions, all radiological rooms in which intravascular X-ray contrast studies are performed must have the tools, devices and medicines necessary for emergency medical care.

Premedication with antihistamine and glucocorticoid drugs is used to prevent the side effects of RCS on the eve of the X-ray contrast study, and one of the tests is also performed to predict the patient's hypersensitivity to RCS. The most optimal tests are: determination of histamine release from peripheral blood basophils when mixed with RCS; the content of total complement in the blood serum of patients assigned for X-ray contrast examination; selection of patients for premedication by determining the levels of serum immunoglobulins.

Among the rarer complications, there may be "water" poisoning during barium enema in children with megacolon and gas (or fat) vascular embolism.

A sign of "water" poisoning, when a large amount of water is quickly absorbed through the walls of the intestine into the bloodstream and an imbalance of electrolytes and plasma proteins occurs, there may be tachycardia, cyanosis, vomiting, respiratory failure with cardiac arrest; death may occur. First aid in this case is intravenous administration of whole blood or plasma. Prevention of complications is to carry out irrigoscopy in children with a suspension of barium in an isotonic saline solution, instead of an aqueous suspension.

Signs of vascular embolism are as follows: the appearance of a feeling of tightness in the chest, shortness of breath, cyanosis, slowing of the pulse and a drop in blood pressure, convulsions, cessation of breathing. In this case, you should immediately stop the introduction of the RCS, put the patient in the Trendelenburg position, start artificial respiration and chest compressions, inject 0.1% - 0.5 ml of adrenaline solution intravenously and call the resuscitation team for possible tracheal intubation, implementation of artificial respiration and carrying out further therapeutic measures.

Private X-ray methods.Fluorography- a method of mass in-line X-ray examination, which consists in photographing an X-ray image from a translucent screen onto a fluorographic film with a camera. Film size 110×110 mm, 100×100 mm, rarely 70×70 mm. The study is performed on a special x-ray machine - a fluorograph. It has a fluorescent screen and an automatic roll film transfer mechanism. The image is photographed using a camera on a roll film (Fig. 1.8). The method is used in a mass examination for the recognition of pulmonary tuberculosis. Along the way, other diseases can be detected. Fluorography is more economical and productive than radiography, but is significantly inferior to it in terms of information content. The dose of radiation in fluorography is greater than in radiography.

Rice. 1.8. Fluoroscopy scheme. 1 − x-ray tube; 2 - object; 3 - luminescent screen; 4 − lens optics; 5 - camera.

Linear tomography designed to eliminate the summation nature of the X-ray image. In tomographs for linear tomography, an x-ray tube and a film cassette are driven in opposite directions (Fig. 1.9).

During the movement of the tube and cassette in opposite directions, an axis of movement of the tube is formed - a layer that remains, as it were, fixed, and on the tomographic image, the details of this layer are displayed as a shadow with rather sharp outlines, and the tissues above and below the layer of the axis of movement are smeared and not are revealed on the image of the specified layer (Fig. 1.10).

Linear tomograms can be performed in the sagittal, frontal and intermediate planes, which is unattainable with step CT.

X-ray diagnostics- medical and diagnostic procedures. This refers to combined X-ray endoscopic procedures with medical intervention (interventional radiology).

Interventional radiological interventions currently include: a) transcatheter interventions on the heart, aorta, arteries and veins: vascular recanalization, dissociation of congenital and acquired arteriovenous fistulas, thrombectomy, endoprosthesis replacement, installation of stents and filters, vascular embolization, closure of atrial and ventricular septal defects , selective administration of drugs into various parts of the vascular system; b) percutaneous drainage, filling and sclerotherapy of cavities of various localization and origin, as well as drainage, dilatation, stenting and endoprosthesis replacement of ducts of various organs (liver, pancreas, salivary gland, lacrimal canal, etc.); c) dilatation, endoprosthetics, stenting of the trachea, bronchi, esophagus, intestines, dilatation of intestinal strictures; d) prenatal invasive procedures, radiation interventions on the fetus under ultrasound control, recanalization and stenting of the fallopian tubes; e) removal of foreign bodies and stones of various nature and different localization. As a navigational (guiding) study, in addition to X-ray, an ultrasonic method is used, and ultrasonic devices are equipped with special puncture sensors. The types of interventions are constantly expanding.

Ultimately, the subject of study in radiology is the shadow image. The features of the shadow x-ray image are:

An image consisting of many dark and light areas - corresponding to areas of unequal attenuation of X-rays in different parts of the object.

The dimensions of the X-ray image are always increased (except for CT) compared to the object under study, and the larger the further the object is from the film, and the smaller the focal length (distance of the film from the focus of the X-ray tube) (Fig. 1.11).

When the object and film are not in parallel planes, the image is distorted (Figure 1.12).

Summation image (except tomography) (Fig. 1.13). Therefore, x-rays must be made in at least two mutually perpendicular projections.

Negative image on X-ray and CT.

Each tissue and pathological formations detected during radiation

Rice. 1.13. The summation nature of the x-ray image in radiography and fluoroscopy. Subtraction (a) and superposition (b) of X-ray image shadows.

research, are characterized by strictly defined features, namely: number, position, shape, size, intensity, structure, nature of the contours, the presence or absence of mobility, dynamics over time.

An important component of the functional analysis of teeth, jaws and TMJ is radiography. X-ray examination methods include intraoral dental radiography, as well as a number of extraoral radiography methods: panoramic radiography, orthopantomography, TMJ tomography and teleroentgenography.

Panoramic x-ray shows the image of one jaw, orthopantomogram - both jaws.

Teleroentgenography (radiography at a distance) is used to study the structure of the facial skeleton. For radiography of the TMJ, the methods of Parm, Schüller, as well as tomography are used. Plain radiographs are of little use for functional analysis: the joint space is not visible on them throughout, there are projection distortions, overlays of surrounding bone tissues.

Tomography of the temporomandibular joint

Undoubted advantages over the above methods have tomography (sagittal, frontal and axial projections), which allows you to see the joint space, the shape of the articular surfaces. However, tomography is a cut in one plane, and in this study it is impossible to assess the overall position and shape of the outer and inner poles of the TMJ heads.

The fuzziness of the articular surfaces on tomograms is due to the presence of a shadow of smeared layers. In the region of the lateral pole it is an array of the zygomatic arch, in the region of the medial pole it is the petrous part of the temporal bone. The tomogram is clearer if there is a cut in the middle of the head, and the greatest changes in pathology are observed at the poles of the heads.
On tomograms in the sagittal projection, we see a combination of displacement of the heads in the vertical, horizontal and sagittal planes. For example, the narrowing of the joint space found on a sagittal tomogram may be the result of an outward displacement of the head, and not upwards, as is commonly believed; expansion of the joint space - displacement of the head inward (medially), and not just down (Fig. 3.29, a).

Rice. 3.29. Sagittal tomograms of the TMJ and a scheme for their evaluation. A - topography of the TMJ elements on the right (a) and left (b) when the jaws are closed in the position of the central (1), right lateral (2) occlusion and with the mouth open (3) in the norm. The gap between the bone elements of the joint is visible - a place for the articular disc; B - scheme for the analysis of sagittal tomograms: a - angle of inclination of the posterior slope of the articular tubercle to the main line; 1 - anterior joint gap; 2 - upper articular gap; 3 - posterior joint gap; 4 - height of the articular tubercle.

The expansion of the joint space on one side and its narrowing on the other is considered a sign of the displacement of the lower jaw to the side where the joint space is narrower.

The internal and external sections of the joint are determined on the frontal tomograms. Due to the asymmetry of the location of the TMJ in the space of the facial skull on the right and left, it is not always possible to obtain an image of the joint on both sides on one frontal tomogram. Tomograms in the axial projection are rarely used due to the complex positioning of the patient. Depending on the objectives of the study, tomography of the TMJ elements is used in lateral projections in the following positions of the lower jaw: with maximum closure of the jaws; at the maximum opening of the mouth; in the position of physiological rest of the lower jaw; in "habitual occlusion".

When tomography in the lateral projection on the Neodiagno-max tomograph, the patient is placed on the imaging table on the stomach, the head is turned in profile so that the joint under study is adjacent to the film cassette. The sagittal plane of the skull should be parallel to the plane of the table. In this case, a cutting depth of 2.5 cm is most often used.

On tomograms of the TMJ in the sagittal projection, when the jaws are closed in the position of central occlusion, the articular heads normally occupy a centric position in the articular fossae. The contours of the articular surfaces are not changed. The articular gap in the anterior, upper and posterior sections is symmetrical on the right and left.

Average dimensions of the joint space (mm):

In the anterior section - 2.2±0.5;
in the upper section - 3.5±0.4;
in the posterior section - 3.7+0.3.

On tomograms of the TMJ in the sagittal projection with the mouth open, the articular heads are located against the lower third of the articular fossae or against the tops of the articular tubercles.

To create a parallelism of the sagittal plane of the head and the plane of the tomograph table, immobility of the head during tomography and maintaining the same position during repeated studies, a craniostat is used.

On tomograms in the lateral projection, the width of individual sections of the joint space is measured according to the method of I.I. Uzhumetskene (Fig. 3.29, b): assess the size and symmetry of the articular heads, the height and slope of the posterior slope of the articular tubercles, the amplitude of the displacement of the articular heads during the transition from the position of central occlusion to the position of the open mouth.
Of particular interest is the method of X-ray cinematography of the TMJ. Using this method, it is possible to study the movement of the articular heads in dynamics [Petrosov Yu.A., 1982].

CT scan

Computed tomography (CT) makes it possible to obtain intravital images of tissue structures based on the study of the degree of X-ray absorption in the area under study. The principle of the method is that the object under study is illuminated layer by layer with an x-ray beam in different directions as the x-ray tube moves around it. The unabsorbed part of the radiation is recorded using special detectors, the signals from which are fed into the computer system (computer). After mathematical processing of the received signals on a computer, an image of the studied layer ("slice") is built on the matrix.

The high sensitivity of the CT method to changes in the X-ray density of the tissues under study is due to the fact that the resulting image, in contrast to conventional X-ray, is not distorted by superposition of images of other structures through which the X-ray beam passes. At the same time, the radiation load on the patient during CT examination of the TMJ does not exceed that during conventional radiography. According to the literature, the use of CT and its combination with other additional methods make it possible to carry out the most precise diagnostics, reduce radiation exposure and solve those issues that are difficult or not at all solved using layered radiography.

The assessment of the degree of absorption of radiation (X-ray density of tissues) is carried out on a relative scale of absorption coefficients (KP) of X-ray radiation. In this scale for 0 units. H (H - Hounsfield unit) absorption in water is taken as 1000 units. N. - in the air. Modern tomographs allow capturing density differences of 4-5 units. N. On CT scans, denser areas with high CP values ​​appear light, and less dense areas with low CP values ​​appear dark.

Using modern 3rd and 4th generation computed tomography scanners, it is possible to isolate 1.5 mm thick layers with instant image reproduction in black and white or color, as well as to obtain a three-dimensional reconstructed image of the area under study. The method makes it possible to store the obtained tomograms on magnetic media indefinitely and to repeat their analysis at any time using traditional programs embedded in the computer of a computer tomograph.

Advantages of CT in the diagnosis of TMJ pathology:

Complete reconstruction of the shape of the bony articular surfaces in all planes based on axial projections (reconstructive image);
ensuring the identity of the TMJ shooting on the right and left;
lack of overlays and projection distortions;
the possibility of studying the articular disc and masticatory muscles;
playback of the image at any time;
the ability to measure the thickness of articular tissues and muscles and evaluate it from two sides.

The use of CT for the study of the TMJ and masticatory muscles was first developed in 1981 by A. Hiils in his dissertation on clinical and radiological studies in functional disorders of the dentofacial system.

The main indications for the use of CT are: fractures of the articular process, craniofacial congenital anomalies, lateral displacements of the lower jaw, degenerative and inflammatory diseases of the TMJ, tumors of the TMJ, persistent joint pain of unknown origin, resistant to conservative therapy.

CT allows you to completely recreate the forms of bone articular surfaces in all planes, does not cause imposition of images of other structures and projection distortions [Khvatova V.A., Kornienko V.I., 1991; Pautov I.Yu., 1995; Khvatova V.A., 1996; Vyazmin A.Ya., 1999; Westesson P., Brooks S., 1992, etc.]. The use of this method is effective for both diagnosis and differential diagnosis of organic changes in the TMJ that are not clinically diagnosed. In this case, the ability to assess the articular head in several projections (straight and reconstructive sections) is of decisive importance.

In case of TMJ dysfunction, CT examination in the axial projection provides additional information about the state of bone tissues, the position of the longitudinal axes of the articular heads, and reveals the hypertrophy of the masticatory muscles (Fig. 3.30).

CT in the sagittal projection makes it possible to differentiate TMJ dysfunction from other joint lesions: injuries, neoplasms, inflammatory disorders [Pertes R., Gross Sh., 1995, etc.].

On fig. 3.31 shows CT of the temporomandibular joint in the sagittal projection on the right and left and diagrams for them. The normal position of the articular discs was visualized.

We give an example of the use of CT for the diagnosis of TMJ disease.

Patient M., aged 22, complained of pain and articular clicks on the right when chewing for 6 years. During the examination, it was revealed: when opening the mouth, the lower jaw shifts to the right, and then zigzag with a click to the left, painful palpation of the external pterygoid muscle on the left. Orthognathic bite with a small incisal overlap, intact dentition, chewing teeth on the right are more worn than on the left; right-sided type of chewing. When analyzing functional occlusion in the oral cavity and on jaw models installed in the articulator, a balancing supercontact was revealed on the distal slopes of the palatine tubercle of the upper first molar (erasing delay) and the buccal tubercle of the second lower molar on the right. On the tomogram in the sagittal projection, no changes were found. On CT scan of the temporomandibular joint in the same projection in the position of central occlusion, the displacement of the right articular head backwards, narrowing of the posterior joint space, forward displacement and deformation of the articular disc (Fig. 3.32, a). On CT scan of the temporomandibular joint in the axial projection, the thickness of the external pterygoid muscle is 13.8 mm on the right, and 16.4 mm on the left (Fig. 3.32, b).

Diagnosis: balancing supercontact of the palatine tubercle 16 and the buccal tubercle in the left lateral occlusion, right-sided type of chewing, hypertrophy of the external pterygoid muscle on the left, asymmetry in the size and position of the articular heads, muscular-articular dysfunction, anterior dislocation of the TMJ disk on the right, displacement of the articular head posteriorly.

Teleroentgenography

The use of teleroentgenography in dentistry made it possible to obtain images with clear contours of the soft and hard structures of the facial skeleton, to carry out their metric analysis and thereby clarify the diagnosis [Uzhumetskene I.I., 1970; Trezubov V.N., Fadeev R.A., 1999, etc.].

The principle of the method is to obtain an X-ray image at a large focal length (1.5 m). When taking an image from such a distance, on the one hand, the radiation load on the patient is reduced, on the other hand, the distortion of facial structures is reduced. The use of cephalostats ensures that identical images are obtained during repeated studies.

A teleroentgenogram (TRG) in direct projection allows diagnosing anomalies of the dentoalveolar system in the transversal direction, in the lateral projection - in the sagittal direction. The TRG displays the bones of the facial and brain skull, the contours of soft tissues, which makes it possible to study their correspondence. TRG is used as an important diagnostic method in orthodontics, orthopedic dentistry, maxillofacial orthopedics, and orthognathic surgery. The use of TRG allows:
to diagnose various diseases, including anomalies and deformities of the facial skeleton;
plan the treatment of these diseases;
predict the expected results of treatment;
monitor the course of treatment;
objectively evaluate long-term results.

So, when prosthetics of patients with deformations of the occlusal surface of the dentition, the use of TRG in the lateral projection makes it possible to determine the desired prosthetic plane, and therefore, to resolve the issue of the degree of grinding of hard tissues of the teeth and the need for their devitalization.

With the complete absence of teeth on the teleroentgenogram, it is possible to check the correctness of the location of the occlusal surface at the stage of setting the teeth.

X-ray cephalometric analysis of the face in patients with increased tooth wear makes it possible to more accurately differentiate the form of this disease, to choose the optimal tactics of orthopedic treatment. In addition, by evaluating TRH, one can also obtain information on the degree of atrophy of the alveolar parts of the upper and lower jaws and determine the design of the prosthesis.
To decipher the TRG, the image is fixed on the screen of the negatoscope, a tracing paper is attached to it, onto which the image is transferred.

There are many methods for analyzing TRG in lateral projections. One of them is the Schwartz method, based on the use of the plane of the base of the skull as a guide. In doing so, it is possible to determine:

The location of the jaws in relation to the plane of the anterior part of the base of the skull;
the location of the TMJ in relation to this plane;
front base length
turnip hole.

TRG analysis is an important method for diagnosing dentoalveolar anomalies, which makes it possible to identify the causes of their formation.

With the help of computer tools, it is possible not only to improve the accuracy of the analysis of TRH, save time for their decoding, but also to predict the expected results of treatment.

V.A. Khvatova
Clinical gnathology

Basic methods of X-ray examination

Classification of methods of X-ray examination

X-ray techniques

Basic Methods	Additional Methods	Special methods - additional contrast is needed
Radiography	Linear tomography	X-ray negative substances (gases)
Fluoroscopy	Sonography	X-ray positive substances	Heavy metal salts (barium oxide sulfac)
Fluorography	Kymography	Iodine-containing water-soluble substances
Electro-radiography	Electrokymography	ionic
	Stereo X-ray	non-ionic
	X-ray cinematography	Iodine-containing fat-soluble substances
	CT scan	Tropic action of the substance.
	MRI

Radiography is a method of X-ray examination, in which an image of an object is obtained on an X-ray film by direct exposure to a radiation beam.

Film radiography is performed either on a universal X-ray machine or on a special tripod designed only for shooting. The patient is positioned between the x-ray tube and the film. The part of the body to be examined is brought as close as possible to the cassette. This is necessary to avoid significant magnification of the image due to the divergent nature of the X-ray beam. In addition, it provides the necessary image sharpness. The X-ray tube is installed in such a position that the central beam passes through the center of the part of the body being removed and perpendicular to the film. The part of the body to be examined is exposed and fixed with special devices. All other parts of the body are covered with protective screens (eg, lead rubber) to reduce radiation exposure. Radiography can be performed in the vertical, horizontal and inclined position of the patient, as well as in the position on the side. Shooting in different positions allows you to judge the displacement of organs and identify some important diagnostic features, such as fluid spreading in the pleural cavity or fluid levels in intestinal loops.

An image that shows a part of the body (head, pelvis, etc.) or the entire organ (lungs, stomach) is called an overview. Pictures on which an image of the part of the organ of interest to the doctor is obtained in the optimal projection, the most beneficial for the study of one or another detail, are called sighting. They are often produced by the doctor himself under the control of translucence. Snapshots can be single or burst. A series may consist of 2-3 radiographs, on which various states of the organ are recorded (for example, gastric peristalsis). But more often, serial radiography is understood as the production of several radiographs during one examination and usually in a short period of time. For example, with arteriography, up to 6-8 pictures per second are produced using a special device - a seriograph.

Among the options for radiography, shooting with direct magnification of the image deserves mention. Magnifications are achieved by moving the X-ray cassette away from the subject. As a result, the image of small details that are indistinguishable in ordinary images is obtained on the radiograph. This technology can only be used with special X-ray tubes with very small focal spot sizes - about 0.1 - 0.3 mm2. To study the osteoarticular system, an image magnification of 5-7 times is considered optimal.

X-rays can show any part of the body. Some organs are clearly visible in the images due to natural contrast conditions (bones, heart, lungs). Other organs are clearly displayed only after their artificial contrasting (bronchi, blood vessels, heart cavities, bile ducts, stomach, intestines, etc.). In any case, the x-ray picture is formed from light and dark areas. The blackening of x-ray film, like photographic film, occurs due to the reduction of metallic silver in its exposed emulsion layer. To do this, the film is subjected to chemical and physical processing: it is developed, fixed, washed and dried. In modern X-ray rooms, the entire process is fully automated due to the presence of processors. The use of microprocessor technology, high temperature and high-speed reagents can reduce the time for obtaining x-rays to 1-1.5 minutes.

It should be remembered that an X-ray image in relation to the image visible on a fluorescent screen during transmission is a negative. Therefore, transparent areas on the x-ray are called dark (“blackouts”), and dark areas are called light (“enlightenments”). But the main feature of the radiograph is different. Each beam on its way through the human body crosses not one, but a huge number of points located both on the surface and in the depths of tissues. Therefore, each point on the image corresponds to a set of real points of the object, which are projected onto each other. The x-ray image is summation, planar. This circumstance leads to the loss of the image of many elements of the object, since the image of some details is superimposed on the shadow of others. This implies the basic rule of X-ray examination: the examination of any part of the body (organ) must be carried out in at least two mutually perpendicular projections - direct and lateral. In addition to them, images in oblique and axial (axial) projections may be needed.

Radiographs are studied in accordance with the general scheme for the analysis of beam images.

The method of radiography is used everywhere. It is available to all medical institutions, simple and easy for the patient. Pictures can be taken in a stationary X-ray room, in the ward, in the operating room, in the intensive care unit. With the correct choice of technical conditions, fine anatomical details are displayed in the image. A radiograph is a document that can be stored for a long time, used for comparison with repeated radiographs and presented for discussion to an unlimited number of specialists.

Indications for radiography are very wide, but in each individual case they must be justified, since X-ray examination is associated with radiation exposure. Relative contraindications are an extremely severe or highly agitated condition of the patient, as well as acute conditions requiring emergency surgical care (for example, bleeding from a large vessel, open pneumothorax).

Benefits of radiography

1. Wide availability of the method and ease of research.

2. Most studies 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 second examination is necessary, since the images obtained are operator-dependent).

Disadvantages of radiography

1. "Freezing" of the image - the complexity of assessing the function of an organ.

2. The presence of ionizing radiation that can have a harmful effect on the organism under study.

3. The information content of classical radiography is much lower than such modern methods of medical imaging 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 layered series of images obtained by modern tomographic methods.

4. Without the use of contrast agents, radiography is practically uninformative for the analysis of changes in soft tissues.

Electroradiography is a method of obtaining an x-ray image on semiconductor wafers and then transferring it to paper.

The electro-radiographic process includes the following steps: plate charging, exposure, development, image transfer, image fixation.

Plate charging. A metal plate coated with a selenium semiconductor layer is placed in the charger of the electroroentgenograph. In it, an electrostatic charge is imparted to the semiconductor layer, which can be maintained for 10 minutes.

Exposure. X-ray examination is carried out in the same way as in conventional radiography, only a plate cassette is used instead of a film cassette. Under the influence of X-ray irradiation, the resistance of the semiconductor layer decreases, it partially loses its charge. But in different places of the plate, the charge does not change in the same way, but in proportion to the number of X-ray quanta falling on them. A latent electrostatic image is created on the plate.

Manifestation. An electrostatic image is developed by spraying a dark powder (toner) onto the plate. Negatively charged powder particles are attracted to those areas of the selenium layer that have retained a positive charge, and to a degree proportional to the charge.

Transferring and fixing the image. In an electroretinograph, the image from the plate is transferred by a corona discharge to paper (writing paper is most often used) and fixed in a pair of fixative. The plate after cleaning from the powder is again suitable for consumption.

The electroradiographic image differs from the film image in two main features. The first is its large photographic latitude - both dense formations, in particular bones, and soft tissues are well displayed on the electroroentgenogram. With film radiography, this is much more difficult to achieve. The second feature is the phenomenon of contour underlining. On the border of fabrics of different density, they seem to be painted on.

The positive aspects of electroroentgenography are: 1) cost-effectiveness (cheap paper, for 1000 or more shots); 2) the speed of obtaining an image - only 2.5-3 minutes; 3) all research is carried out in a darkened room; 4) the “dry” nature of image acquisition (that is why, abroad, electroradiography is called xeroradiography - from the Greek xeros - dry); 5) storage of electroroentgenograms is much easier than that of x-ray films.

At the same time, it should be noted that the sensitivity of the electro-radiographic plate is significantly (1.5-2 times) inferior to the sensitivity of the film-intensifying screen combination used in conventional radiography. Therefore, when shooting, it is necessary to increase the exposure, which is accompanied by an increase in radiation exposure. Therefore, electroradiography is not used in pediatric practice. In addition, artifacts (spots, stripes) quite often appear on electroroentgenograms. With this in mind, the main indication for its use is an urgent x-ray examination of the extremities.

Fluoroscopy (X-ray transillumination)

Fluoroscopy is a method of X-ray examination in which an image of an object is obtained on a luminous (fluorescent) screen. The screen is cardboard coated with a special chemical composition. This composition under the influence of x-rays begins to glow. The intensity of the glow at each point of the screen is proportional to the number of X-ray quanta that fell on it. On the side facing the doctor, the screen is covered with lead glass, which protects the doctor from direct exposure to x-rays.

The fluorescent screen glows faintly. Therefore, fluoroscopy is performed in a darkened room. The doctor must get used (adapt) to the darkness within 10-15 minutes in order to distinguish a low-intensity image. The retina of the human eye contains two types of visual cells - cones and rods. The cones are responsible for the perception of color images, while the rods are the mechanism for dim vision. It can be figuratively said that a radiologist with normal transillumination works with “sticks”.

Radioscopy has many advantages. It is easy to implement, publicly available, economical. It can be performed in the X-ray room, in the dressing room, in the ward (using a mobile X-ray machine). Fluoroscopy allows you to study the movement of organs with a change in body position, contraction and relaxation of the heart and pulsation of blood vessels, respiratory movements of the diaphragm, peristalsis of the stomach and intestines. Each organ is easy to examine in different projections, from all sides. Radiologists call this method of research multi-axis, or the method of rotating the patient behind the screen. Fluoroscopy is used to select the best projection for radiography in order to perform so-called sightings.

Benefits of Fluoroscopy The main advantage over radiography is the fact of the study in real time. This allows you to evaluate not only the structure of the organ, but also its displacement, contractility or extensibility, the passage of a contrast agent, and fullness. The method also allows you to quickly assess the localization of some changes, due to the rotation of the object of study during transillumination (multiprojection study). With radiography, this requires taking several pictures, which is not always possible (the patient left after the first picture without waiting for the results; a large flow of patients, in which pictures are taken in only one projection). Fluoroscopy allows you to control the implementation of some instrumental procedures - catheter placement, angioplasty (see angiography), fistulography.

However, conventional fluoroscopy has its weaknesses. It is associated with a higher radiation exposure than radiography. It requires darkening of the office and careful dark adaptation of the doctor. After it, there is no document (snapshot) left that could be stored and would be suitable for re-consideration. But the most important thing is different: on the screen for transmission, small details of the image cannot be distinguished. This is not surprising: take into account that the brightness of a good negatoscope is 30,000 times greater than that of a fluorescent screen during fluoroscopy. Due to the high radiation exposure and low resolution, fluoroscopy is not allowed to be used for screening studies of healthy people.

All the noted shortcomings of conventional fluoroscopy are eliminated to a certain extent if an X-ray image intensifier (ARI) is introduced into the X-ray diagnostic system. Flat URI type "Cruise" increases the brightness of the screen by 100 times. And URI, which includes a television system, provides amplification by several thousand times and makes it possible to replace conventional fluoroscopy with X-ray television transmission.