Ultrasound examination (or sonography) is one of the most modern, affordable, informative methods of instrumental diagnostics. The main advantage of ultrasound is its non-invasiveness, i.e., in the process of research on the skin and other tissues, as a rule, there is no mechanical damaging effect. This type of diagnosis is not associated with pain or other discomfort for the patient. Unlike common radiography, radiation that is dangerous to the human body is not used during ultrasound. From this article you will learn what an ultrasound scan is, how it is performed and much more.
The principle of ultrasound
Sonography for specialists makes it possible to notice even the smallest changes in the organ and detect the disease at the stage at which clinical symptoms have not yet developed. As a result of this, a patient who has undergone an ultrasound procedure in a timely manner increases many times the chances of an absolute recovery.
The first successful studies of patients using ultrasound were carried out in the mid-50s of the 20th century. Previously, the principle was used only in military sonars to detect underwater objects.
To study various internal organs, high-frequency sound waves are used - ultrasound. Since the “picture” is displayed in real time, this allows doctors to identify a number of processes that occur in the patient’s body, in particular, movement in blood vessels.
Physics-based ultrasound is based on the piezoelectric effect. In the role of piezoelectric elements, which alternately operate as a transmitter and receiver of the signal, single crystals of quartz or barium titanate are used. Under the influence of high-frequency sound vibrations, charges are formed on the surface, and during the supply of current to the crystals, mechanical vibrations are created, which are accompanied by ultrasound radiation. These vibrations are due to the rapid change in the shape of single crystals.
The so-called transducer piezoelectric elements are considered the basis of diagnostic devices. By themselves, they represent the basis of the sensors, where, in addition to crystals, a sound-absorbing special wave filter, an acoustic lens, designed to focus the ultrasound device on the necessary wave, is also provided.
Upon reaching the boundary of zones with different impedances, the wave beam changes markedly. Some of them continue to move in a previously defined direction, while another part is reflected. The reflection coefficient will depend on the difference in the resistance index of the two media.
And now it is worthwhile to consider in more detail what ultrasound is.
Ultrasound of the heart
For studies of the heart, as well as blood vessels, a type of ultrasound examination such as echocardiography is used. With the assessment of the general state of blood flow, the technique using Dopplerography allows you to see changes in the heart valves, establish the size of the atria and ventricles, and also the change in the structure and thickness of the myocardium, that is, the heart muscle. During the course of the diagnosis, it is also possible to examine the coronary artery region.
The intensity of narrowing of the gaps of blood vessels allows to identify constant wave Doppler ultrasound. As for the pumping function, it is evaluated using Doppler pulse research. Regurgitation, that is, the movement of blood through the valves in the opposite physiological direction, can be detected using Doppler color mapping.
Echocardiography diagnoses such serious diseases as the latent form of coronary heart disease and rheumatism, as well as notice neoplasms. There are no contraindications to this diagnostic procedure. In the presence of any detected chronic pathologies in the cardiovascular system, it will be advisable to undergo an echocardiography at least 1 time per year.
Ultrasound of the abdomen
What happens ultrasound yet? This should, of course, include a survey of the abdomen. Ultrasound of the abdominal cavity is most often used to monitor the condition of the liver, spleen, gall bladder, main vessels and kidneys. It should be noted that for ultrasound examination of the abdominal cavity, as well as the pelvis, the frequency that is in the range of 2.5-3.5 MHz is considered the most optimal.
Ultrasound of the kidneys
So, we continue to consider what ultrasound is. Thanks to ultrasound of the kidneys, it is possible to identify cystic neoplasms in the patient, the presence of calculi (i.e. stones), and enlargement of the renal pelvis. This kidney diagnosis is necessarily carried out with hypertension.
Thyroid ultrasound
Speaking about what types of ultrasound there are, we should mention the thyroid gland. It is indicated in the case of an increase in this organ and with the appearance of nodular neoplasm, as well as when discomfort, pain in the neck area occurs. This study must be assigned to all residents living in ecologically disadvantaged areas and regions, as well as in regions where the amount of iodine content in drinking water is very low.
Pelvic ultrasound
Such a diagnosis is necessary to assess the condition of all organs in the female reproductive system. This ultrasound can detect early pregnancy. In men, this method provides an opportunity to identify various pathological changes in the prostate gland.
Breast ultrasound
What are ultrasound organs? One of these is an ultrasound of the mammary glands, which is used to identify the nature of the neoplasm in the chest. To ensure tight contact of a special sensor with the skin surface, a gel is applied on it before the procedure, which contains styrene compounds, as well as glycerin.
Ultrasound during pregnancy
Scanning is now widely used in obstetrics, as well as perinatal diagnosis - the study of the baby at different times. It allows you to determine the pathology of the development of the child. During pregnancy, an ultrasound examination is recommended to be passed at least three times.
An ultrasound gynecologist is able to identify some developmental abnormalities:
- lack of solid palate in the fetus;
- malnutrition;
- polyhydramnios, low water;
- placenta previa.
It is very problematic to do without ultrasound during the diagnosis of multiple pregnancy, as well as in determining the location of the fetus.
Methods of carrying out the procedure
Considering what types of gynecological ultrasounds are, it is worth mentioning those types that differ in their implementation methods. An ultrasound examination of the pelvis is considered basic in the diagnosis of diseases in the field of gynecology. Therefore, if you are wondering about what kind of ultrasound gynecology is, this should be attributed to this.
It is checked with this diagnosis the structure of the uterus, fallopian tubes, the structure and size of the bladder, the size of the ovary, and blood supply to the genitals. But what are pelvic ultrasounds, depending on the method of conducting? The study may be conducted:
- Transabdominally. It is carried out by an external method through the wall of the abdomen, which is why it is most acceptable for virgins, pregnant women and patients with poorly developed genital external organs. If you do not know what are the ultrasounds during pregnancy, then this should be attributed to this.
- Transvaginally. The sensor with which the picture is generated is inserted into the vagina. With this method, there is some discomfort.
- Transrectally. During this, the sensor is inserted directly into the rectum. The method is informative, unpleasant, therefore it is applied only if the above two were not possible.
Advantages and disadvantages of ultrasound
Advantages are as follows:
- harmlessness;
- cheapness;
- safety for children and pregnant women;
- short duration of the study;
- no invasive intervention;
- receiving information in real time;
- receiving volumetric image and video frames in 4D.
The disadvantages of ultrasound are as follows:
- limiting the clarity of images by sensor area;
- low resolution;
- the need to prepare abdominal organs before ultrasound (diet, carminative drugs);
- a large number of different interference in the study due to the heterogeneity of the human body environment.
In addition, the sizes of the tumor studied formations are served on a slice, in which the diameter depends on the angle of the sensor. Possible diagnostic errors in evaluating tumor growth: with direct penetration of waves, only one size is determined, and in the case of a deviation of several degrees, this section size increases significantly.