X-rays are a special type of electromagnetic oscillations that are created in the tube of the x-ray machine during a sudden stop of electrons. An x-ray is a common procedure, but some people want to know more about it. What is x-ray? How is it done?
The following X-ray properties have found application in medical practice:
- Huge penetration. X-rays successfully pass through various tissues of the human body;
- X-rays cause light reflection of individual chemical elements. This property underlies fluoroscopy;
- The photochemical effect of ionizing rays allows creating informative images;
- X-rays have an ionizing effect;
During an X-ray scan, various organs, tissues, and structures act as targets for X-rays. An insignificant radioactive load can disrupt metabolism, and
- Prolonged exposure to radiation can cause acute or chronic radiation sickness.
X-ray machines are devices that are used not only for diagnostic and therapeutic purposes in medicine but also in various fields of industry (flaw detectors), as well as in other areas of human life.
The x-ray apparatus consists of:
- emitter tubes (lamp) – one or more pieces;
- a device that powers the apparatus and controls radiation parameters;
- tripods that facilitate device management;
- converters of X-ray to a visible image.
X-ray devices are divided into several groups depending on how they are arranged and where they are used:
- stationary – as a rule, they are installed in radiological departments and clinics;
- mobile – intended for use in the departments of surgery and traumatology, in intensive care units and on an outpatient basis;
- portable, dental (used by dentists).
When passing through the human body, x-rays are projected onto the film. However, the angle of reflection of the waves can be different and this affects the image quality. The bones are best seen in the pictures because calcium absorbs x-rays most of all.
Types of diagnostics
In medical practice, x-rays have found application in the following diagnostic methods:
- Fluoroscopy is a study of moving body structures. It’s often done while a contrast dye moves through the part of the body being examined. A continuous X-ray beam is passed through the body part and sent to a video monitor so that the body part and its motion can be seen in detail;
- Radiography is the main type of diagnostics. It is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object;
- X-ray and fluoroscopy with contrast. This type of diagnosis is indispensable in the study of hollow organs and soft tissues;
- Fluorography is an examination with small-format x-rays that allow using it massively during preventive lung examinations;
- Computed tomography (CT) is a diagnostic method that allows studing the human body in detail through a combination of x-rays and digital processing;
- There is a computer reconstruction of layered x-ray images. This is the most informative method of radiation diagnostics.
There are some types of x-ray studies:
- the spine and peripheral parts of the skeleton;
- abdominal cavity;
- detailed image of all teeth with jaws adjacent to the facial skeleton;
- checking the patency of the fallopian tubes using x-rays;
- x-ray examination of the mammary gland with a low proportion of radiation;
- radiopaque examination of the stomach and duodenum;
- diagnosis of the gallbladder and ducts using contrast;
- examination of the colon with a retrograde introduction of a radiopaque drug into it.
The abdominal x-ray is divided into panoramic radiography and a procedure performed using contrast. Fluoroscopy is usually used to determine pathologies in the lung. X-ray examination of the spine, joints and other parts of the skeleton is a very popular diagnostic method.
Neurologists, traumatologists and orthopedists cannot make an accurate diagnosis for their patients without using this type of examination. It shows an x-ray of a hernia of the spine, scoliosis, various microtraumas, disorders of the bone-ligamentous apparatus (pathology of the healthy foot), fractures (wrist joint) and much more.
Most of the diagnostic manipulations associated with the use of x-rays do not require special preparation, but there are exceptions. If it is an examination of stomach, intestines or lumbosacral spine, then 2-3 days before radiography, you must adhere to a special diet that reduces flatulence and fermentation processes.
When examining the gastrointestinal tract, it is required that the patient makes cleansing enemas on the eve of the procedure and on the day of the procedure, or the intestines can be cleansed with the help of pharmacy laxatives (oral preparations or microclysters).
When examining the abdominal organs, you should not eat, drink, smoke at least 3 hours before the procedure. Before you do a mammogram, you need to visit a gynecologist. An x-ray examination of the breast should be done at the beginning of the period after the end of menstruation. If a woman who is planning a breast examination has implants, then this must be reported to the radiologist.
After entering the X-ray room, the patient must remove elements of clothing or jewelry that contain metal, and also leave a mobile phone outside the room. Typically, the patient is asked to strip to the waist if a chest or peritoneum is examined. If it is necessary to perform a limb x-ray, then the patient can wear clothes. All parts of the body that cannot be diagnosed should be covered with a protective lead apron.
Pictures can be taken in various positions. But most often the patient is standing or lying. If you need a series of images from different angles, then the radiologist gives the patient commands to change the position of the body. If a stomach X-ray is performed, then the patient will need to take the position of Trendelenburg.
This is a special posture in which the pelvic organs are slightly higher than the head. As a result of manipulations, negatives show light areas of denser structures and dark areas, indicating the presence of soft tissues. Decoding and analysis of each area of the body are performed according to certain rules.
The maximum permissible effective dose of radiation is 15 mSv per year. As a rule, only people who need regular x-ray control (after serious injuries) receive such a portion of radiation. If the patient does one x-ray, mammography and dental x-rays during the year, then he or she can be completely calm since this radiation load will not exceed 1.5 mSv.
Acute radiation sickness can occur only if a person receives radiation at a dose of 1000 mSv once. But if the patient is not a liquidator at a nuclear power plant, then he or she must make 25 thousand X-ray photographs and a thousand x-rays of the spine in one day in order to receive such radiation exposure. And this is nonsense.
The radiation doses that a person receives during standard examinations (even if their number is increased) are not able to have a noticeable negative effect on the body. Therefore, X-rays can be done as often as required by medical indications. However, this principle does not apply to pregnant women.
X-rays are contraindicated for pregnant women, especially in the first trimester. If circumstances force the woman to take an x-ray during pregnancy (serious injuries during an accident), then it’s necessary to use the maximum protective measures for the abdomen and pelvic organs. During breastfeeding, women are allowed to do both x-rays and fluorography.
At the same time, according to many experts, a breastfeeding woman does not even need to pump milk. Small children do not undergo fluorography. This procedure can be done from the age of 15. Pediatrics resort to X-ray only when children have increased radiosensitivity to ionizing radiation (on average 2-3 times higher than adults), which creates a high risk of both somatic and genetic effects of radiation.
X-ray and radiography have a number of contraindications:
- active tuberculosis;
- endocrine pathologies of the thyroid gland;
- general severe condition of the patient;
- lactation period (for radiography using contrast);
- serious disorders in the work of the heart and kidneys;
- internal bleeding;
- individual intolerance to contrast agents.
You can take an x-ray in many medical centers. If a radiographic or fluoroscopic examination is done on digital systems, then the patient gets a lower dose of radiation. But even a digital x-ray can be considered safe but only if the permissible frequency of the procedure is not exceeded.