Functional diagnostics is the direction of medicine, based on the application of instrumental methods of research. The methods used in functional diagnostics are bloodless, painless, and are characterized by a high degree of safety for the patient.
Functional diagnostics makes it possible to detect violations of the functions of organs, as well as to quantify the severity of these disorders.
Instrumental research methods are needed to establish an accurate diagnosis, choice of treatment tactics, and evaluate the effectiveness of the treatment.
Surgical hospital uses the wide specter of diagnostic methods. It includes diagnostics with ultrasound, roentgen research, MRI, KT.
- Main part
- Ultrasound methods
One of the most significant achievements of recent medicine is the introduction of ultrasound in a wide clinical practice. To obtain an image, the property of reflection and refraction of the ultrasonic wave from media with different acoustic densities and moving blood elements is used. Ultrasound diagnostic methods are practically harmless, which allows them to be repeatedly repeated during the dynamic control of the patient. These methods allow us to identify pathological changes in most organs and tissues of the human body.
Ultrasound scanning (ultrasound) allows to determine:
the presence and size of focal formations in the parenchymal organs;
thickness and structure of the wall of hollow organs;
presence of pathological formations in the lumen of the hollow organ;
accumulation of fluid in the cavities of the human body;
infiltrates and abscesses in soft tissues and abdominal cavity.
Ultrasound dopplerography (USDG) is based on recording blood flow by changing the frequency of the sound signal reflected from moving particles. The method allows to determine the blood flow rate and thereby assess the functional state of the vessels. This method is named after the Austrian mathematician and physicist Christian Andreas Doppler (1803-1853). The scientist, strolling along the railroad tracks, drew attention to the fact that the buzzer of the approaching locomotive sounds different than that of the retreating one. This observation formed the basis for the theory of reflection and this method of investigation.
Duplex scanning (DS) Further improvement of ultrasound means led to the appearance of duplex scanning – a method that combines the possibilities of anatomical and functional examination of blood vessels. At the same time, it became possible to simultaneously visualize the vessel under study and obtain physiological information about the parameters of the blood flow. In recent years, the capabilities of duplex scanning have been extended through the use of color Doppler mapping (CDC) blood flow. Coding blood flow in red or blue, allows you to judge the direction of blood flow, quickly differentiate arteries and veins, trace their anatomical course and location, determine the presence of pathological formations in their lumen. The color saturation of the stream corresponds to the rate of blood flow. The sufficiently high diagnostic accuracy of the method for detecting obliterating arterial diseases and the pathology of veins makes duplex angioscanning the main method of screening diagnostics in cardiovascular surgery.
- X-ray methods
Chest X-ray reveals lung diseases, the presence of gas and fluid in the pleural cavity, as well as free gas in the subdiaphragmatic space with perforation of the hollow organ, to reveal hollow organs in the thoracic cavity with diaphragmatic hernia or traumatic rupture of the diaphragm.
Survey radiography of the abdominal cavity is performed mainly with suspicion of perforation of the hollow organ, intestinal obstruction and renal colic. The study is usually performed in the upright position of the patient. In the perforation of a hollow organ containing air, a survey radiography reveals a free gas in the abdominal cavity. In the standing position, it accumulates under the dome of the diaphragm or under the liver, in the position on the back – at the front abdominal wall.
Mammography is widely used in the diagnosis of benign and malignant neoplasms of the mammary glands and serves as the main screening method for preventive examinations of women over 35 years of age.
Contrastive radiography of the gastrointestinal tract is the standard technique for detecting the pathology of the esophagus and small intestine, since almost all diseases of other parts of the gastrointestinal tract can be more effectively detected by endoscopic methods. Contrast study of the stomach is also used for stomach tumors and when it is impossible to perform gastroscopy. Urgent examination of the upper gastrointestinal tract with the use of contrast agents, used to diagnose the perforation of the esophagus. An examination of the passage of contrast medium along the intestine is carried out to detect acute intestinal obstruction and sources of intestinal bleeding. The test is performed on an empty stomach, and in case of stenosis of the gastric outlet, except for this, a gastric lavage is performed 2-3 hours before the test.
Percutaneous transhepatic cholangiography is performed in those cases when ERCP can not establish and eliminate the cause of mechanical jaundice. The study is usually completed by introducing into the dilated bile duct drainage for external bile drainage. With this method of investigation, it is possible to damage the liver with the development of bleeding or the flow of bile into the free abdominal cavity, which requires urgent surgical intervention.
Radiocontrast angiography is an X-ray examination of blood vessels, produced by injecting contrast preparations into vessels through their puncture or catheterization. Thanks to the percutaneous catheterization of vessels according to the method of Seldinger, simple, fast and relatively safe access to almost any organ was obtained. In arteriography, stenoses, occlusions, aneurysms and other changes in the arteries are revealed. Phlebography allows you to assess the pathology of the main veins.
X-ray computed tomography (CT) is based on obtaining layered images of the human body using an X-ray tube rotating around it. It allows to obtain a series of sections of organs and tissues, to judge the presence of pathological formations in them, to evaluate their mutual relations with surrounding organs and vessels. To obtain an image of the arteries intravenously injected non-ionic contrast drug. Visualization is carried out in the arterial phase of its circulation. For the study of vessels (PKT-angiography), spiral, multispiral or electron-beam computer tomographs are used, which make it possible to obtain a large number of sections in a minimum amount of time. Thus, it became possible to study rapidly occurring dynamic processes. RKT is one of the best methods for diagnosing many diseases. The method makes it possible to assess the degree of organ damage, tumors, foci of destruction, identify vascular aneurysms, limited fluid accumulations, infiltrative and suppurative complications.
Magnetic resonance tomographs operate on completely different principles than RKT, X-ray radiation is not used here. MRI uses a strong magnetic field, which causes the protons of the nucleus of the hydrogen atom, which is part of the water of the human body, to shift slightly. Returning to their previous position, they emit radiation, which is recorded by sensors and analyzed by a computer, which makes it possible to build images of organs and tissues in any desired plane. MRI has a greater resolving power than RKT, and allows more accurate diagnosis of abnormal organic changes in organs and soft tissues.
Currently, MRI is used for detailed targeted examination of the anatomical structures of the brain, spine, abdominal and thoracic cavities, vessels, joints, biliary and pancreatic ducts.
- Endoscopic methods
Esophagogastroduodenoscopy. The main indication for her conduct are diseases of the upper digestive tract. This method in the vast majority of patients can diagnose tumors, erosive and ulcerative lesions of the mucosa, establish their localization, the presence of bleeding or the risk of its recurrence, and even stop it by clipping, coagulation or sclerosing the bleeding vessel. Gastroscopy is also used to remove foreign bodies.
Recto-manoscopy – examination of the rectus and distal sigmoid colon – allows diagnosing tumors, hemorrhoids and inflammatory diseases. When preparing for a sigmoidoscopy, purifying enemas are performed the night before and in the morning 1, 5-2 hours before the study.
Colonoscopy consists in examination of the entire colon. It is performed with suspicion of a tumor, as well as with intestinal bleeding in order to identify the cause of the developed complication and its localization. Colonoscopy allows you to remove polyps from the colon and perform a biopsy from tumors. For a good visualization of the intestinal wall, a complete cleansing of the intestine from the contents is required, therefore preparation for colonoscopy is carried out with greater care than with irrigoscopy.
Bronchoscopy allows to determine inflammatory and oncological lesions of bronchi and lungs. It is widely used for the sanation of the tracheobronchial tree in the postoperative period.
Diagnostic laparoscopy consists in examination of the abdominal cavity organs under conditions of artificial pneumoperitoneum by a laparoscope inserted into the abdominal cavity through the puncture of the anterior abdominal wall. Laparoscopy allows you to get a complete visual picture of the state of the abdominal cavity organs. Indications for laparoscopy after introduction into a wide clinical practice of ultrasound and RCT significantly decreased. Laparoscopy is used in difficult clinical situations with the impossibility of clarifying the diagnosis on the basis of non-invasive methods of investigation.
III. Conclusion
Thus, it can be concluded that an important part of the clinical diagnosis is the knowledge of semiology and the ability to think logically. At the same time, the clinical diagnosis of the doctor is a key part of the diagnosis, as well as his intuitive thinking. Diagnosis is a creative process in which not only the conscious but also the subconscious mind participates, in which intuition played and will play a certain role, however demanding a sufficiently critical attitude to itself and verification in practice.
Practical verification of the truth of the diagnosis is a complex problem at the present time. In this regard, the judgment about the correctness of the diagnosis based on the effectiveness of treatment of patients is of relative importance, since the treatment can be independent of the diagnosis in cases when the disease is recognized but poorly treated or the condition of the patients worsens with an unclear diagnosis. In addition, pathogenetic therapy can be effective at certain stages of the course of a large group of diseases with different etiologies, but some general mechanisms of development. Nevertheless, in the part of observations, and now this method of verifying the truth of the diagnosis can have a positive value.
