CT, MRI, ultrasound, X-ray: what are the studies and why are they needed. Everything you need to know about x-rays: acquisition procedure, assessment of diagnostic hazards and image interpretation

For the diagnosis of various diseases of the lungs, bones and other organs and tissues of the human body, radiography (or X-ray) has been used in medicine for 120 years - this is a simple and error-free technique that has saved a huge number of lives due to the accuracy of diagnosis and the safety of the procedure.

X-rays, discovered by the German physicist Wilhelm Roentgen, pass almost unhindered through soft tissues. The bone structures of the body do not let them through, as a result of which shadows of different intensity are formed on x-rays, accurately reflecting the state of the bones and internal organs.

Radiography is one of the most researched and proven diagnostic techniques in clinical practice, the effect of which on the human body has been perfectly studied for more than a century of use in medicine. In Russia (in St. Petersburg and Kyiv), thanks to this technique, already in 1896, a year after the discovery of X-rays, operations were successfully performed using X-ray images on photographic plates.

Despite the fact that modern X-ray equipment is constantly being improved and is a high-precision medical device that allows for detailed diagnostics, the principle of obtaining a picture has remained unchanged. The tissues of the human body, which have different densities, transmit invisible X-rays with varying degrees of intensity: soft, healthy structures practically do not delay them, while bones absorb them. The resulting images look like a collection of shadow images. An X-ray image is a negative, on which bone structures are indicated in white, soft in gray, and air spaces in black. The presence of pathological changes in the internal organs, for example, in the lungs, is displayed as a lighter spot on the pulmonary pleura or in the segments of the lung itself. The description of the radiograph made is the basis on which doctors can judge the state of certain research objects.

If in the 20th century the equipment made it possible to conduct, basically, only the examination of the chest and limbs, then modern fluoroscopy is used for high-precision diagnostics of various organs using a wide range of X-ray equipment.

Types and projections of radiography

Various types of radiography are used to conduct preventive studies and in-depth diagnostics in medicine. X-ray techniques are classified:

• in the form:
  • overview, allowing you to completely cover various areas of the body;
  • sighting, which is usually carried out with a deep diagnosis of a certain area of ​​​​an organ using a special nozzle on an x-ray machine;
  • layer-by-layer, during which parallel sections of the studied zone are performed.
• by type of equipment used:
  • traditional film;
  • digital, which provides the ability to record the resulting image on removable media;
  • three-dimensional. This includes computed, multispiral and other types of tomography;
  • fluorographic, which allows for a safe preventive examination of the lungs;
• special:
  • mammographic, for examining the breast in women;
  • hysterosalpingographic, used to examine the uterus and fallopian tubes;
  • densitometric, for the diagnosis of osteoporosis and others.

The enumeration of various methods shows how in demand and indispensable in the diagnosis is radiology. Modern physicians can use various forms of research to detect pathologies in most organs and vital systems of the human body.

Why do x-rays

X-rays in modern medicine are used for preventive examinations and directed diagnostics. Without such an examination, you can not do with:

• bone fractures;
• damage to internal organs as a result of external trauma;
• diagnosis of breast cancer and a number of other oncological diseases;
• examination of the lungs and other organs of the chest;
• treatment and prosthetics of teeth;
• deep study of brain structures;
• scanning of sections of vessels with suspicion of an aneurysm, and so on.

The method of conducting an x-ray examination is chosen by the doctor, depending on the presence of indications and contraindications for it in the patient. Compared to some modern volumetric imaging techniques, traditional x-rays are the safest. But it is not indicated for certain categories of patients.

Contraindications

Despite the safety of diagnostics, patients experience the effects of ionizing radiation, which adversely affects the bone marrow, red blood cells, epithelium, reproductive organs and the retina. Absolute contraindications for x-rays are:

• pregnancy;
• the age of the child is up to 14 years;
• severe condition of the patient;
• active form of tuberculosis;
• pneumothorax or bleeding;
• thyroid disease.

For children and pregnant women, such an examination is prescribed only in extreme cases, when the threat to life is greater than the potential harm from the procedure. Whenever possible, try to resort to alternative methods. So, if a doctor needs to diagnose a tumor in a pregnant woman, then ultrasound is used instead of an x-ray.

What is needed for x-ray preparation

To examine the condition of the spine, stomach or jaw bones, special preparation is not needed. The patient must take off his clothes and metal objects before undergoing such an examination. The absence of foreign objects on the body ensures the accuracy of the x-ray.

Preparation is required only when using a contrast agent, which is introduced to x-ray certain organs in order to increase the visualization of the results. An injection of a contrast agent is done some time before the procedure or directly in the process.

How an x-ray is done

All x-rays are taken in specially equipped rooms, where there are protective screens that prevent radiation from reaching non-translucent organs of the body. The study does not take long. Depending on the technique used for the procedure, radiography is performed in different positions. The patient can stand, lie down or sit.

Is it possible to go at home

Proper conditions for shooting with an X-ray machine of one modification or another are created in specially equipped rooms, where there is protection from ionizing rays. Such equipment has large dimensions and is used only in stationary conditions, which makes it possible to achieve maximum safety of the procedure.

To conduct preventive examinations of a large number of people in areas remote from large clinics, mobile fluorographic rooms can be used, which completely repeat the situation in stationary medical facilities.

How many times can x-rays be taken

Translucence of tissues and organs is carried out as many times as this or that diagnostic technique allows. The safest are fluorography and x-rays. The doctor may refer the patient several times for such an examination, depending on the results obtained earlier and the goals set. Volumetric pictures are taken according to indications.

When prescribing radiography, it is important not to exceed the maximum permitted total radiation dose per year, which is 150 mSv. For information: exposure when performing a chest x-ray in one projection is 0.15-0.4 mSv.

Where can I get an x-ray, and its average cost

An X-ray can be done in almost any medical institution: in public clinics, hospitals, private centers. The cost of such an examination depends on the area under study and the number of images taken. As part of compulsory health insurance or according to allocated quotas in public hospitals, organ scans can be done free of charge with a referral from a doctor. In private medical institutions, such a service will need to be paid. The price starts from 1500 rubles and may vary in different private medical centers.

What does an x-ray show

What does the x-ray show? The state of a certain organ can be seen on the picture taken or on the monitor screen. A variety of dark and light shades on the resulting negative allows doctors to judge the presence or absence of certain pathological changes in a particular section of the organ under study.

Deciphering the results

Only a qualified doctor who has a long clinical practice and understands the features of various pathological changes in certain organs of the body can read x-rays. Based on what he saw in the picture, the doctor makes a description of the received radiograph in the patient's chart. In the absence of atypical light spots or blackouts on soft tissues, cracks and fractures on the bones, the doctor fixes the healthy state of a particular organ. Only an experienced doctor who knows the X-ray anatomy of a person and the symptoms of the disease of the organ whose image is being taken can accurately decipher an x-ray.

What do the inflammatory foci in the picture indicate

When translucence of soft tissues, joints or bones in the presence of pathological changes in them, symptoms characteristic of a particular disease appear. The area affected by inflammation absorbs X-rays differently than healthy tissues. As a rule, such a zone contains pronounced foci of darkening. An experienced doctor immediately determines the type of disease from the resulting image in the picture.

What do diseases look like on x-rays?

When transferring the image to the film, places with pathological changes stand out against the background of healthy tissue. When the damaged bones are translucent, the places of deformations and displacements are clearly visible, which allows the traumatologist to make an accurate prognosis and prescribe the correct treatment. If shadows are found on the lungs, this may indicate pneumonia, tuberculosis, or cancer. A qualified specialist must differentiate the identified deviations. But areas of enlightenment in this organ often indicate pleurisy. Specific symptoms are characteristic for each type of pathology. To make a correct diagnosis, it is necessary to perfectly master the X-ray anatomy of the human body.

The advantages of the technique, and what is the negative effect of x-rays on the body

X-ray images obtained as a result of X-ray transmission give an accurate understanding of the state of the organ under study and allow doctors to make an accurate diagnosis. The minimum duration of such an examination and modern equipment significantly reduce the possibility of receiving a dose of ionizing radiation dangerous to human health. A couple of minutes is enough for a detailed visualization of the organ. During this time, in the absence of contraindications in the patient, it is impossible to cause irreparable harm to the body.

How to minimize the effects of exposure

All forms of diagnostics of diseases using x-rays are carried out only for medical reasons. Fluorography is considered the safest, which is recommended to be performed annually for the purpose of early detection and prevention of tuberculosis and lung cancer. All other procedures are prescribed taking into account the intensity of X-ray radiation, while information about the dose received is entered into the patient's card. The specialist always takes this indicator into account when selecting diagnostic methods, which allows not to exceed the norm.

Is it possible to do x-rays for children

According to international and domestic regulations, any research based on exposure to ionizing radiation is allowed to be carried out by persons over 14 years of age. As an exception, a doctor may prescribe an X-ray to a child only if he is suspected of having dangerous lung diseases with the consent of the parents. Such an examination is necessary in acute situations requiring a quick and accurate diagnosis. Before this, the specialist always correlates the risks of the procedure and the threat to the life of the child if it is not performed.

Is X-ray possible during pregnancy

Such an examination is usually not prescribed during the period of gestation, especially in the first trimester. If it is so necessary that the lack of timely diagnosis threatens the health and life of the future mother, then during it a lead apron is used to protect the internal organs from X-rays. Against the background of other similar methods, X-rays are the safest, but doctors in most cases prefer not to carry them out during pregnancy, protecting the fetus from harmful ionizing effects.

Alternative to x-ray

The 120-year practice of using X-rays and similar techniques (fluorography, computed, multislice, positron emission tomography, and others) has shown that today there is no more accurate way to diagnose a number of pathologies. With the help of an X-ray study, you can quickly determine lung diseases, bone injuries, identify diverticula in aged patients, make high-quality retrograde urethrography, timely detect oncology at an early stage of development, and much more.

An alternative to such a diagnosis in the form of ultrasound can only be prescribed to pregnant women or patients with contraindications to x-rays.

Radiography is a non-invasive diagnostic method that allows you to obtain an image of individual parts of the human body on x-ray film or digital media using ionizing radiation. X-ray allows you to study the anatomical and structural features of organs and systems, helping in the diagnosis of many internal pathologies that cannot be seen during a routine examination.

Taking x-rays

Description of the method

The radiographic research method is based on the use of x-rays. X-rays emitted by the device's sensor have a high penetrating power. Passing through the tissues of the human body, the rays ionize the cells and linger in them in different volumes, as a result of which a black-and-white image of the anatomical region under study appears on the x-ray film. Bone tissue is more radiopaque, so it looks lighter in the pictures, darker areas are soft tissues that do not absorb x-rays well.

The discovery of X-rays made a huge breakthrough in the diagnosis of many diseases that until that time could only be detected at a late stage, when treatment became difficult or even impossible.

Today, most polyclinics and large hospitals are equipped with X-ray machines, with the help of which you can quickly clarify the diagnosis and draw up a treatment plan. In addition, X-rays are also used for preventive examinations, helping to diagnose serious pathologies in the early stages. The most common type of preventive examination is fluorography, the purpose of which is the early diagnosis of pulmonary tuberculosis.

There are several methods of X-ray examination, the difference between which lies in the method of fixing the image:

• Classical radiography - the image is obtained by direct exposure of x-rays to the film.
• Fluorography - the image is displayed on the monitor screen, from where it is subsequently printed on a small format film.

• Digital x-ray - a black and white image is transferred to a digital medium.
• Electroroentgenography - the image is transferred to special plates, from where it is then transferred to paper.
• Teleradiography - with the help of a special television system, the image is displayed on the TV screen.
• X-ray - the image is displayed on a fluorescent screen.

The method of digital radiography more accurately reflects the picture of the area under study, which greatly facilitates the diagnosis and selection of a treatment regimen for the identified pathology.

In addition to differences in the method of image fixation, radiography is divided into types depending on the object of study:

• X-ray of the spinal column and peripheral parts of the skeleton (limbs).
• Chest x-ray.
• X-ray of teeth (intraoral, extraoral, orthopantomography).
• Mammary gland - mammography.
• Colon - irrigoscopy.
• Stomach and duodenum - gastroduodenography.
• Bile ducts and gallbladder - cholegraphy and cholecystography.
• Uterus - metrosalpingography.

Hysterosalpingogram

Indications and contraindications for examination

Radiography, like fluoroscopy and other X-ray methods of examination, is carried out only if there are indications, and there are many of them - such a study is prescribed to patients for visualization of internal organs and systems in order to identify pathological abnormalities in their structure. Radiography is indicated in the following cases:

• Diagnosis of diseases of the skeleton and internal organs.
• Checking the success of the treatment and identifying undesirable consequences.
• Monitoring the position of installed catheters and tubes.

Before the start of the study, each patient is interviewed to clarify possible contraindications to radiography.

These include:

• active form of tuberculosis.
• Thyroid dysfunction.
• Severe general condition of the patient.
• Pregnancy period.

Pregnant X-rays are done only for health reasons.

• Breastfeeding if a contrast agent is needed.
• Heart and kidney failure (relative contraindication for contrasting).
• Bleeding.
• Allergy to iodine-containing substances in case of need for the use of contrast agents.

Advantages of radiography over other methods:

• The main advantage of X-ray examination is the availability of the method and the simplicity of its implementation. Most clinics are equipped with the necessary equipment, so there is usually no problem with the place where you can scan. The price of x-rays is usually low.

Radiography is available in almost any medical institution

• Before the study, there is no need to carry out complex preparation. The exception is radiography with contrast.
• Finished images are stored for a long time, so they can be shown to different specialists even after several years.

The main disadvantage of X-ray examination is the radiation load on the body, but subject to certain rules (scanning on modern devices and the use of personal protective equipment), undesirable consequences can be easily avoided.

Another disadvantage of the method is that the obtained images can only be viewed in one plane. In addition, some organs are almost not displayed on the pictures, so for their study it is necessary to inject a contrast agent. Old-style devices do not make it possible to obtain clear images, so it is often necessary to prescribe additional studies to clarify the diagnosis. To date, the most informative is scanning on devices with digital recorders.

The difference between radiography and fluoroscopy

Fluoroscopy is one of the main types of X-ray examination. The meaning of the technique is to obtain an image of the area under study on a fluorescent screen using x-rays in real time. Unlike radiography, the method does not allow obtaining graphic images of organs on film, however, it allows assessing not only the structural features of the organ, but also its displacement, filling, and stretching. Fluoroscopy often accompanies catheter placement and angioplasty. The main disadvantage of the method is a higher radiation exposure in comparison with radiography.

How is the examination carried out?

Woman lying on the x-ray machine table

The technique of radiography for different organs and systems is similar, differing only in the positioning of the patient and the injection site of the contrast agent. Immediately before entering the office, you should remove all metal objects from yourself, already in the office you need to put on a protective apron. Depending on the purpose of the study, the patient is placed on a couch in a certain position or seated on a chair. A film cassette is placed behind the area to be examined, after which the probe is directed. During the study, the laboratory assistant leaves the room, the patient must remain completely still to obtain clear images.

In some cases, the scan is performed in several projections - the specialist will tell the patient about the change in posture. When using a contrast agent, it is administered in the right way before the start of the scan. After the study is completed, the specialist checks the obtained images to assess their quality, if necessary, the scan is repeated.

Deciphering the results

In order to correctly "read" the picture, you need to have the appropriate qualifications, it is very difficult for an ignorant person to do this. The images obtained during the study are negatives, so the denser structures of the body appear as light areas, and the soft tissues appear as dark formations.

When deciphering each area of ​​the body, doctors follow certain rules. For example, with a chest x-ray, specialists evaluate the relative position and structural features of organs - the lungs, heart, mediastinum, examine the ribs and collarbones for damage (fractures and cracks). All characteristics are evaluated according to the age of the patient.

Doctor examining an x-ray of the lungs

For the final diagnosis of one x-ray is often not enough - you should rely on the data of the survey, examination, other laboratory and instrumental methods of examination. Do not engage in self-diagnosis, the radiography method is still quite complicated for people without a higher medical education, its purpose requires special indications.

X-ray examination - the use of X-rays in medicine to study the structure and function of various organs and systems and to recognize diseases. X-ray examination is based on the unequal absorption of X-ray radiation by different organs and tissues, depending on their volume and chemical composition. The stronger the X-ray radiation absorbed by a given organ, the more intense the shadow cast by it on the screen or film. For x-ray examination of many organs, artificial contrasting is used. A substance is introduced into the cavity of an organ, into its parenchyma or into its surrounding spaces, which absorbs X-rays to a greater or lesser extent than the organ under study (see Shadow contrast).

The principle of X-ray examination can be represented in the form of a simple diagram:
x-ray source → research object → radiation receiver → doctor.

The X-ray tube serves as a source of radiation (see). The object of the study is the patient, directed to identify pathological changes in his body. In addition, healthy people are also examined to detect latent diseases. A fluoroscopic screen or a film cassette is used as a radiation receiver. With the help of a screen, fluoroscopy is performed (see), and with the help of a film - radiography (see).

X-ray examination allows you to study the morphology and function of various systems and organs in the whole organism without disturbing its vital activity. It makes it possible to examine organs and systems at different age periods, allows you to detect even small deviations from the normal picture and thus make a timely and accurate diagnosis of a number of diseases.

X-ray examination should always be carried out according to a certain system. First, they get acquainted with the complaints and the history of the disease of the subject, then with the data of other clinical and laboratory studies. This is necessary because X-ray examination, despite all its importance, is only a link in the chain of other clinical studies. Next, they draw up a plan for an x-ray study, that is, they determine the sequence of applying certain methods to obtain the required data. After completing the X-ray examination, they begin to study the obtained materials (X-ray morphological and X-ray functional analysis and synthesis). The next step is the comparison of x-ray data with the results of other clinical studies (clinical-radiological analysis and synthesis). Further, the obtained data are compared with the results of previous X-ray studies. Repeated x-ray examinations play an important role in the diagnosis of diseases, as well as in the study of their dynamics, in monitoring the effectiveness of treatment.

The result of the x-ray examination is the formulation of the conclusion, which indicates the diagnosis of the disease or, if the data obtained are insufficient, the most likely diagnostic possibilities.

With proper technique and methodology, X-ray examination is safe and cannot harm the subjects. But even relatively small doses of X-ray radiation are potentially capable of causing changes in the chromosomal apparatus of germ cells, which can manifest itself in subsequent generations by changes harmful to offspring (developmental abnormalities, a decrease in overall resistance, etc.). Although each X-ray examination is accompanied by the absorption of a certain amount of X-ray radiation in the patient's body, including his gonads, the likelihood of this kind of genetic damage in each specific case is negligible. However, in view of the very high prevalence of X-ray examinations, the problem of safety in general deserves attention. Therefore, special regulations provide for a system of measures to ensure the safety of X-ray examinations.

These measures include: 1) conducting X-ray examinations according to strict clinical indications and special care when examining children and pregnant women; 2) the use of advanced x-ray equipment, which allows to reduce the radiation exposure to the patient to a minimum (in particular, the use of electron-optical amplifiers and television devices); 3) the use of various means of protecting patients and personnel from the effects of X-ray radiation (enhanced radiation filtration, the use of optimal technical conditions for shooting, additional protective screens and diaphragms, protective clothing and protectors of the gonads, etc.); 4) reducing the duration of X-ray examination and the time spent by personnel in the field of action of X-ray radiation; 5) systematic dosimetric monitoring of radiation exposure of patients and personnel of X-ray rooms. Dosimetry data are recommended to be entered in a special column of the form, on which a written conclusion is given on the X-ray examination performed.

X-ray examination may only be carried out by a doctor with special training. The high qualification of the radiologist ensures the effectiveness of radiodiagnostics and the maximum safety of all x-ray procedures. See also X-ray diagnostics.

X-ray examination (X-ray diagnostics) is an application in medicine for studying the structure and function of various organs and systems and for recognizing diseases.

X-ray examination is widely used not only in clinical practice, but also in anatomy, where it is used for the purposes of normal, pathological and comparative anatomy, as well as in physiology, where X-ray examination makes it possible to observe the natural course of physiological processes, such as contraction of the heart muscle, respiratory movements of the diaphragm, peristalsis of the stomach and intestines, etc. An example of the use of X-ray examination for preventive purposes is (see) as a method of mass examination of large human contingents.

The main methods of X-ray examination are (see) and (see). Fluoroscopy is the simplest, cheapest and most easily performed method of X-ray examination. An essential advantage of fluoroscopy is the ability to conduct research in various arbitrary projections by changing the position of the body of the subject in relation to the translucent screen. Such a multi-axis (poly-positional) study makes it possible to establish during the transillumination the most advantageous position of the organ under study, in which certain changes are revealed with the greatest clarity and completeness. At the same time, in some cases it is possible not only to observe, but also to feel the organ under study, for example, the stomach, gallbladder, intestinal loops, by the so-called X-ray palpation, carried out in lead rubber or using a special device, the so-called distinctor. Such targeted (and compression) under the control of a translucent screen provides valuable information about the displacement (or non-displacement) of the organ under study, its physiological or pathological mobility, pain sensitivity, etc.

Along with this, fluoroscopy is significantly inferior to radiography in terms of the so-called resolution, i.e., the detectability of details, since, compared with the image on a translucent screen, it more fully and accurately reproduces the structural features and details of the organs under study (lungs, bones, internal relief of the stomach and intestines etc.). In addition, fluoroscopy, compared with radiography, is accompanied by higher doses of x-ray radiation, i.e., increased radiation exposure to patients and staff, and this requires, despite the rapidly transient nature of the phenomena observed on the screen, to limit the time of transmission as much as possible. Meanwhile, a well-executed radiograph, reflecting the structural and other features of the organ under study, is available for repeated study by different people at different times and is, therefore, an objective document that has not only clinical or scientific, but also expert, and sometimes forensic value. .

Repeated radiography is an objective method of dynamic observation of the course of various physiological and pathological processes in the organ under study. A series of radiographs of a certain part of the same child, taken at different times, makes it possible to trace in detail the process of development of ossification in this child. A series of radiographs made over a long period of a number of chronically current diseases (stomach and duodenum, and other chronic bone diseases) makes it possible to observe all the subtleties of the evolution of the pathological process. The described feature of serial radiography makes it possible to use this method of X-ray examination also as a method of monitoring the effectiveness of therapeutic measures.

I regularly go to the dentist, where they constantly do x-rays of the oral cavity. And a gynecologist cannot do without an ultrasound ... How dangerous are these studies and what are they for?

I. Krysova, Izhevsk

x-ray

On one side of the person is a source of X-ray radiation, on the other - a photographic film that displays how the rays pass through different tissues and organs.

When to use. To determine bone fractures, lung diseases, in dentistry and neurology. X-ray machines are used during heart surgery to monitor the process in real time.

Mammography

It is also based on x-rays.

When to use. For breast examination. There are mammograms for screening - preventive examinations. And diagnostic mammographs are used if there is already a suspicion of breast cancer. Such a device can immediately take a sample of the tumor to determine its malignancy - to make a biopsy. Modern devices with a microdose characteristic (microdose) reduce the level of radiation by 2 times.

CT

This is also a type of x-ray, but body pictures are taken from different angles. The computer produces three-dimensional images of a body part or internal organ. A detailed image of the whole body can be obtained in one procedure. A modern spectral tomograph will independently determine the types of tissues, show them in different colors.

When to use. In case of injuries - to comprehensively assess the degree of damage. In oncology - to find tumors and metastases.

ultrasound

Ultrasonic waves are reflected differently by muscles, joints, and blood vessels. The computer converts the signal into a two-dimensional or three-dimensional image.

When to use. For diagnosis in cardiology, oncology, obstetrics and gynecology. The device shows the internal organs in real time. This is the safest method.

MRI

It creates an electromagnetic field, captures the saturation of tissues with hydrogen and transmits this data to the screen. Unlike CT, MRI does not have radiation, but it also produces 3D images. MRI visualizes soft tissues well.

When to use. If you need to examine the brain, spine, abdominal cavity, joints (including under MRI control, operations are performed so as not to touch important areas of the brain - for example, those responsible for speech).

Expert opinions

Ilya Gipp, PhD, head of MRI-guided therapy:

Many of these devices can be used for treatment. For example, a special installation is attached to an MRI machine. It focuses ultrasound waves inside the body, point-wise raising the temperature, and burns out neoplasms - for example, uterine fibroids.

Kirill Shalyaev, director of the largest Dutch manufacturer of medical equipment:

What seemed impossible yesterday is reality today. Previously, CT scans were administered with a drug that slows down the heart. The latest CT scanners make 4 revolutions per second - thanks to this, there is no need to slow down the heart.