Ultrasound is one of the most popular non-invasive methods for assessing the condition of organs and tissues. Ultrasonic waves, when passing through the boundaries of two media, tend to be reflected – these echo signals are captured by the sensor and converted into an image of anatomical structures. The technique makes it possible to visualize the anatomical structure of an organ in real time (including in 3D and 4D modes), identify morphological changes, evaluate its functional abilities and vascularization. This diagnostics can detect a wide range of diseases of the heart and blood vessels, chest organs, abdominal cavity and retroperitoneal space, genitourinary system, musculoskeletal system, soft tissues and surface structures.

Types of research

Various modes are used to obtain diagnostic information during:

• A-mode (one–dimensional echography, amplitude mode) – provides information about the intensity of the reflected signal and the distance between the sensor and the reflecting structures. It is used in ophthalmology (echobiometry), neurology (Echo-EG), otolaryngology.
• B-mode (two–dimensional echography, brightness mode) – reproduces a two-dimensional tomographic image of anatomical structures in real time. The main mode used for most types.
• M-mode (motion mode) – displays the time changes of the A-echogram. It is used mainly in cardiology during echocardiography.
• C-mode – in this type of scanning, A-mode is used to determine the depth of the object under study, and two–dimensional mode is used to form its image at a given depth.
• D-mode (Doppler mode) is based on the principle of frequency shift, which allows visualizing and measuring blood flow in blood vessels. Dopplerograms can be presented in the form of color images (color doppler) or graphic/acoustic waves (spectral doppler). Special methods are color Doppler mapping, energy Doppler, tissue doppler. The combination of B-mode with color Doppler mapping is triplex scanning; the combination of B-mode is ultrasonic duplex scanning.

Depending on the image model obtained on the screen, there are 2D (planar, two-dimensional), 3D (three-dimensional, static) and 4D (volumetric, dynamic, real-time). Despite the fact that almost any internal organs can be examined with the help of 3D/4D technologies, these techniques are most widely used in obstetrics (3D/4D of the fetus).

Ultrasound can be performed by external (percutaneous) or intracavitary (intracorporeal) access. The first category of studies includes transthoracic ultrasound of the mediastinum, transabdominal ultrasound of the pelvic organs or abdominal organs, etc. Intracavitary studies include transesophageal echocardiography, transvaginal ultrasound, endorectal ultrasonography of the rectum, laparoscopic echography, and many others.

Application areas

Ultrasound diagnostics is used in various fields of medicine for examination of adults and children.Depending on the area of echo scanning , the following types of diagnostics are distinguished:

• Ultrasound of the abdominal cavity. It includes an echo scan of the liver, gallbladder and bile ducts, pancreas, spleen. It can be performed both for preventive purposes and in the presence of signs indicating damage to the digestive organs (abdominal pain, jaundice, weight loss, abnormalities in blood biochemical parameters, etc.). In addition to a complex, a study of individual abdominal organs can be carried out: liver and gallbladder, spleen, pancreas. With the help, you can determine the presence of free fluid or blood in the abdominal cavity. As part of a separate diagnostic procedure, a scan of the retroperitoneal space is usually performed – ultrasound of the adrenal glands and retroperitoneal tissue.
• Ultrasound of the thoracic cavity. It may include such independent studies as echocardiography, ultrasound of the pleural cavity and mediastinum. EchoCG is the leading method of diagnosing the anatomical and functional state of the heart in cardiology. It can be performed by transthoracic or transesophageal access, at rest, physical or drug load, electrical stimulation. Diacnostics of pleural cavities is indicated to detect effusion, accumulation of blood and pus, examination of pleural leaflets. Mediastinal ultrasound is used to identify volumetric processes of mediastinal localization.
• Ultrasound of the urinary system. Includes examination of the kidneys, ureters and bladder. In urology, indications for the appointment of such studies may be dysuric disorders, lower back pain and urination, changes in the color and smell of urine, changes in laboratory urine tests. Ultrasound of the kidneys is often performed in combination with the adrenal glands.
• Ultrasound of the female genital organs. It is most often carried out for the purpose of a comprehensive assessment of the state of the reproductive system in women of various ages. It can be performed by transabdominal or transvaginal (less often – trnsrectal), as well as combined access. The types that are independent in their tasks are folliculometry, ultrasound examination, assessment of the patency of the fallopian tubes. At the onset of pregnancy, this diagnostic helps to monitor the development of the fetus, timely detect intrauterine defects, the threat of spontaneous termination of pregnancy and premature birth. For this purpose, within the framework of the pregnancy management program, women are recommended to perform studies in the I, II and III trimesters.
• Ultrasound of the male genitals. It is carried out as part of screening for the detection of adenoma and prostate cancer (prostate cancer), pathology of the testicles and appendages (cryptorchidism, hydrocele, varicocele, cysts), finding out the causes of erectile dysfunction. The study involves an assessment of the structure and vascularization of the male genitalia.
• Ultrasound of the joints (arthrosonography) and spine. They are included in the standards of diagnostic algorithms for the study of the musculoskeletal system. These types can be prescribed by an orthopedic traumatologist, rheumatologist, neurologist. Ultrasound imaging is also used during joint puncture, puncture biopsy. Ultrasound densitometry is a convenient screening method for assessing the condition of bone tissue.
• Ultrasound of the structures of the head and neck. Diagnostic procedures combined in this group include a number of independent diagnostic studies that are used in ophthalmology (ultrasound of the eyes), neurology (ultrasonography, Echo-EG), endocrinology (ultrasound of the thyroid gland), otolaryngology (ultrasound of the paranasal sinuses), dentistry (ultrasound of the salivary glands).
• Ultrasound of soft tissues and surface structures. This category includes studies of muscles, tendons, lymph nodes, mammary glands.

Advantages of ultrasound

In many cases, ultrasound does not require any special training of patients and can be performed as soon as possible. Ultrasound scanners can be delivered to any department for examination of bedridden and non-transportable patients, in addition, the use of portable devices makes it possible to conduct ultrasound at home. A big plus is the possibility of simultaneous examination of several organs at once. At the request of the patient, ultrasound can be recorded on an electronic medium – in this case, it becomes possible to obtain a second expert opinion on this study, as well as to compare the results during treatment.