Kidney ultrasound is a diagnostic procedure during which the structure, size and location of the kidneys are visualized using high-frequency sound waves. The results allow us to identify urolithiasis, tumors and cysts, purulent lesions, anomalies in the development of a paired organ. Kidney ultrasound is performed as an independent study and in combination with ultrasound of the adrenal glands, bladder, Dopplerography (duplex and triplex scanning) of blood vessels.
Preparation for kidney ultrasound should begin a few days before the procedure. Compliance with all the rules allows you to minimize the risk of interference in the path of ultrasonic waves, get a clearer image and reliable results. The training program includes the following activities:
- Correction of the diet. For 3-4 days before the study, it is worth following a diet that excludes the use of products that enhance gas formation. Spicy, fatty and fried foods, confectionery, rye bread, cabbage, legumes, dairy products are banned.
- The period of hunger. Ultrasound is best performed on an empty stomach. The optimal meal break is 8-12 hours. If the procedure is carried out in the afternoon or evening, it is permissible to eat dried white bread, fish, meat, reducing the hunger time to 5-6 hours.
- Intake of enterosorbents. After 1-1.5 hours after the last meal, it is recommended to take an enterosorbent, for example, activated charcoal. With increased gas formation, it is worth using carminative preparations.
- Drinking water. If the bladder is examined with ultrasound diagnostics of the kidneys, then an hour before the scan you need to drink half a liter of water without gas, do not urinate until the end of the procedure.
Kidney ultrasound is used to determine the location, number, shape and size of organs. The diagnostic doctor evaluates the nature of the contours, the structure of the parenchyma, the presence or absence of neoplasms, concretions. When scanning the kidneys and adrenal glands, in addition to the parameters described above, the structure and size of the adrenal glands are visualized, the presence of hyperplasia, inflammation, hematomas, tumors is diagnosed. The kidneys together with the bladder are examined if kidney stones are suspected: the result reflects the structure and functioning of these organs, their interaction. Kidney ultrasound together with dopplerometry reveals the characteristics of the blood flow of the kidney vessels.
In healthy people, the kidneys resemble beans in shape, the left organ is located slightly higher than the right, the outer contours are smooth and clear. Parenchyma has homogeneous echogenicity. Normal blood flow is visualized in dark colors, its speed is 50-150 cm/sec. With the help of ultrasound diagnostics , the following pathologies are detected:
- Urolithiasis. Kidney stone disease is accompanied by the formation of stones that look like echo-positive formations. Inclusions with a diameter of 4 mm are clearly visualized. The urinary tract is dilated. With microcalculosis, sand and small stones are determined.
- Nephroptosis. Excessive mobility of the kidneys leads to their displacement – nephroptosis. Omission of the right organ is more often diagnosed, less often – the left, extremely rarely – both. With a displacement of one and a half vertebrae, the I degree of the disease is determined, 2 vertebrae – II degree, 3 vertebrae and more – III degree.
- Neoplasms of the kidneys. Cysts, abscesses and hematomas – neoplasms filled with fluid are displayed as areas of low echogenicity (darkening). The density of tumors is determined by their type, but always differs from the echo density of the renal tissue.
- Pyelonephritis. Characteristic signs of pyelonephritis are an increase in the size and limited mobility of the kidneys, an uneven contour, a compaction of the tissue with a light shade.
- Insufficiency of function. Renal insufficiency is indicated by an increase in the echogenicity of parenchymal tissue, uneven contours, and a decrease in blood flow rate.
- Glomerulonephritis. The diagnosis of glomerulonephritis is confirmed by a decrease in the size of the kidneys, an increased density of tissue displayed in a lighter color.
Any diagnostic examination, including ultrasound, is not interpreted in isolation and cannot serve as the only criterion for the intended diagnosis. The results confirm the assumptions of the urologist made during the clinical examination of the patient, examination, and receipt of the results of blood and urine tests.
The advantages of ultrasound are the absence of contraindications to the procedure, its painlessness, accessibility. The study is conducted for infants, pregnant women, elderly and old people, seriously ill patients. In comparison with kidney MRI, CT and radiography, ultrasound diagnostics has a lower cost, even with a comprehensive examination including vascular Dopplerometry. However, the accuracy of the data is insufficient: it is not always possible to determine the location of the kidney, the nature of the neoplasm, to identify the presence of small inclusions.