Interpretation of kidney ultrasound results. What are the normal sizes of the kidneys according to ultrasound in adults, and will the diagnosis show hydronephrosis, stones and other formations? Description of ultrasound of the kidneys of a healthy person

Kidney ultrasound and urinary system is one of the important informative diagnostic measures for suspected pathologies of these organs. Kidney diseases affect the entire body and can have serious and even fatal complications.

Normal kidney ultrasound findings

The location of the kidneys allows diagnostics and visualization using ultrasound to be carried out with high accuracy and reliability. During a kidney examination, the shape and size of the kidneys, their structure and correct location, as well as the condition of the urinary system are assessed.

Shape and kidney size ultrasound, the thickness of the parenchyma (kidney tissue) is a list of the main indicators characterizing their condition and functional abilities. Normally, the kidneys should be bean-shaped and located on both sides of the spine in the retroperitoneal region. The right kidney is usually located slightly lower than the left. When breathing, the kidneys can move in a vertical direction; normally, the amplitude of movement is 2-3 cm.

The inner cavity of the kidneys, called the pelvis, should ideally be clean, free of sand or stones. With normal ultrasound readings, the parenchyma and kidney tissue have a homogeneous structure, without visible tissue changes. The size of the kidneys depends on a person’s age; in children, they can change as they go through different stages of growing up. In adults, the kidneys can change after 60 years; this process is associated with age-related processes and the aging of the body. Age-related changes are characterized by a decrease in the thickness of the parenchyma by an average of 1 cm. The normal sizes of the kidneys for a middle-aged adult are:

The average length of the kidneys is 10.5 ± 0.8 cm;
The average width is 4.5 ± 0.6 cm;
The thickness of the parenchyma or cortical layer is 1.5-2.5 cm.

Medical studies have shown that the size of healthy kidneys in relation to each other may vary slightly, with the right kidney being slightly smaller than the left. Kidney sizes ultrasound in children depend on the age of the child. In the clinical practice of pediatric urology and nephrology, there is a table of measurements and normal kidney growth in accordance with the stages of a child’s growing up.

What kidney pathologies can ultrasound detect?

When examining the kidneys and urinary system, pathologies of an anatomical, physiological and functional nature can be identified. The most common kidney diseases include:

Kidney stone disease - the presence of sand or stones in the renal pelvis;
Nephritis is an inflammatory process in the kidneys;
Pyelonephritis is an infectious inflammation of the kidneys;
Nephrosis is a dystrophic change in the kidneys;
Kidney failure - partial or complete failure to perform the functions of removing fluid from the body;
Kidney prolapse;
Neoplasms – cysts, tumors;
Pathological changes and disorders of the blood vessels of the kidneys;
Diseases of the ureters (narrowing).

Ultrasound provides reliable information about all types of pathological changes in the kidneys; if it is necessary to clarify the diagnosis or a more detailed picture of the disease, additional diagnostics are performed using Doppler sonography.

In our clinic, you will be able to undergo an ultrasound examination of the kidneys using modern equipment, and competent, experienced uzologists will be able to see pathological changes in the structure of organs or their functioning.

A human organ, a kidney, a vital filter of the human body. It is responsible for cleansing the body of harmful and toxic substances and breakdown products.

When examining this organ using various diagnostic measures, the main indicator of their health is the size of the kidneys.

This indicator of organ health is influenced by many factors, including: the person’s gender; his age; even the mass of the human body.

Therefore, measurements of this organ were taken, which became the norm in determining pathologies and deviations from normal development.

The data obtained are the standard for carrying out diagnostic measures.

Kidneys - anatomical features of the organ

The structure of the kidneys has the structure and elements:

• Nephrons. The smallest part of the structure of the renal organ, consisting of the epithelial canals, the renal body and a huge number of blood vessels. Their numerical composition is approximately equal to one million nephrons.
• The connective tissue of the kidney is parenchyma. Consists of epithelial channels and renal rings. The composition of this part of the organ is the cortex and medulla.
• The cortical mass completely surrounds the kidney and is located under the renal capsule. As professional researchers say and confirm, in one day the kidney parenchyma cleanses the human bloodstream and his blood about 45-55 times.
• As for the medulla, these are 11-20 conical pyramids, which are located at the base of the medullary rays, included in the cortex.
• According to external data, the kidney organ is covered with connective tissue, and in front of the organ there is a serous membrane.
• The cavity in the organ is funnel-shaped and is located inside the human filter (kidney). This funnel receives organic urine from the nephron and redirects it to the ureter. The ureter itself transmits the bladder and is discharged out through the channels. This part of the organ is designated the pelvis.
• The kidney contains the renal artery. This is a blood vessel through which processed substances are delivered to the kidneys, polluting the body with its waste. All this is removed over time through the artery.
• Renal vein of the organ. With the help of this vein, through the bloodstream, this purified state of blood is transferred by the body to the vena cava of the human organ.

These listed types, which make up the kidney structure and anatomical abilities, are beneficial for the affected wards.

What factors influence the size?

As described above, the size of a person’s kidneys is influenced by certain factors. First of all, the gender of the person.

As research data show, the thickness and size, as well as the length and width of the cortical connective layer, significantly exceed those of the female sex.

This is simply explained by the difference in body structure, because a man’s body is also more massive than a weaker female’s.

In addition, studies have shown that there is a difference in the size of a person’s kidney from each other, depending on whether it is left or right. An explanation was also found for this fact - the liver interfering with the development of the right kidney.

Age also produces significant differences in kidney size. This organ grows until the age of 27, after which its development stops and it remains at the same level. With advancing age, the kidneys begin to decrease in size.

Organ development and size

Ultrasound diagnostics (ultrasound) is used to detect kidney pathology. This device is able to detect abnormalities and the size of this organ.

In addition, an ultrasound will show the functions and structure of the kidneys. True, when receiving the results of the study, some additional data can be calculated according to the table.

As experts say, body weight and organ size are closely intertwined. The greater the weight of a person, the larger the kidney and its height and width. What is the norm for adults and their normal size?

Adult organ size

The normal size of the kidneys in an adult is from 75 to 135 mm. Taking the anatomical dimensions, you can determine the length using the vertebrae.

Indeed, according to confirmed data, the size corresponds to the height of 3 lumbar vertebrae, while the width reaches 75 mm.

As for the thickness of the organ, it will be up to 55 mm. Some begin to measure the size by a person’s fist.

The data was verified experimentally, which confirms this statement.

In young men, the thickness of the kidney and its tissues ranges from 12 to 27 mm. With old age, the connective tissue of the organ significantly reduces its size. In people over 60 years old, the thickness becomes 12 mm, and in some cases even less.

Kidney organ size in children

As stated above, the kidney organ and its size depend on body weight and gender. Taking into account that children develop according to individual characteristics, clear criteria for determining sizes have not been established.

Doctors are beginning to navigate statistical data in the context of age development groups.

The kidney pelvis in a newborn has a normal kidney size of 5 mm; up to 4 years, this figure increases by 1 mm. According to statistics, the average size of a person’s kidneys at birth is 48 mm.

• As for ages from 3 to 12 months, the size reaches 60 mm.
• From one to five years, the size of the organ corresponds to 72 mm.
• From five years to 10 years, the size is already 86 mm.
• Age ranges from 10 to 14 years, size up to 100 mm.
• From 14 to 20 years old – 107 mm.

For a more accurate determination, the doctor calculates the height and weight of the patient, a small person.

Organ size on ultrasound

Data when the size of the kidneys is normal can be confirmed by diagnostics using ultrasound. This event is important when determining the disease or examining the ward.

This method will show not only the size, but also the location of organs and their structure. The doctor will not always explain what the epicrisis of examination data says.

Often, he will pass this conclusion on to the attending physician and absolve himself of responsibility. But curiosity overcomes society, and he begins to inquire about his diagnosis.

To do this, we will try to explain the size of the kidneys according to diagnosis. What does it mean? In an adult, the length of the kidneys should be from 11 to 12 centimeters, and the width should be at least 5.5 centimeters, and the thickness should be from 4 to 5.5 cm.

As for the organ, the normal sizes of the kidneys and pelvis should have an acceptable value of 1 to 1.6 centimeters.

Woman's organ

When diagnosed, there are no big differences between women and men. Possible changes can only occur during pregnancy at the time of carrying the fetus.

At this time, the organ lengthens to 2.5 cm. These are acceptable values ​​during pregnancy, which does not pose a risk to the woman’s health.

Kidneys in males

For males, it is necessary to build on generally accepted ultrasound readings. If there is a discrepancy between the results obtained, the doctor will prescribe a more thorough diagnosis to identify the pathology of the disease.

Functional features of the organ

During the biological life of this organ, it passes through itself up to 250 liters of blood per day.

At the same time, the bloodstream is cleansed of pathogenic bacteria and microbes, cleanses the blood of toxins and harmful substances.

The main functions and responsibilities of this body:

• excretory function;
• homeostatic function;
• carry out metabolism;
• support the endocrine system;
• participate in the secretory activity of the body;
• carry out hematopoiesis, which significantly renews the contents of the blood.

Excretory function of the kidneys

The production of urine and its further removal from the body is the main task of the kidney organ.

This function involves the removal of toxins or harmful substances, regulates the presence of salts in the body, and is heavily involved in maintaining blood pressure.

Big problems are caused by the lack of necessary treatment for pathology, and a violation in the excretory systems causes a complete lack of control over the state of the body.

The excretory function itself passes through the nephrons, which control the proper functioning of the organ and the small internal mechanisms of the kidneys.

This function has its own individual stages, which include:

• secretion function;
• filtering human urine and bloodstream;
• reabsorption.

When this system malfunctions, the body begins to choke from toxic poisoning.

Homeostatic function of the body

This function controls the salt and acid-base balances of the human body.

• Water-salt functions – constant maintenance of a liquid substance in the body.
• Acid-base balance – maintaining blood in normal working condition. If there is a malfunction, an irreparable blow to health is caused.

Metabolism

Thanks to the ongoing synthesis of active biological substances, calcium is exchanged and red blood cells appear. This activity improves the metabolism of nutrients and removes toxins from the body.

Kidney dysfunction - organ dysfunction

Kidneys, when the organ is damaged, cause dysfunction to the human body. This occurrence of pathology, in most cases, is asymptomatic, which creates difficulties in identifying the pathology in a timely manner.

After all, it is always simpler and easier to treat the initial stage of a disease than to deal with the consequences of a serious illness.

What symptoms may indicate kidney problems? There are individual symptoms:

• pale skin;
• black circles under the eyes;
• the pain threshold occurs when gallstone disease appears;
• blood pressure increases, which can cause exacerbations of chronic diseases;
• determining the color of urine;
• constant and frequent urination;
• in children, abnormalities are detected only during diagnosis and laboratory tests.

All these factors may be signs of pathological changes in the kidneys, which require urgent intervention by specialists.

Diagnosis and methods

Kidney diseases have a different nature and causes of manifestation. Since the kidneys are responsible not only for purifying the blood.

The manifestations of disturbances and deviations in work may result in renal failure.

What are the symptoms of progression of kidney disease:

• pain in the lower back, at the location of the kidneys;
• severe swelling and redness of the skin in the area where the kidneys are located;
• dark skin appearance;
• frequent urination, sometimes accompanied by painful symptoms;
• strong and unpleasant odor of urine at the time of bowel movement;
• swelling of the facial part in the morning and of the limbs in the evening.

These symptoms of the disease, based on general signs, cannot always confirm kidney pathology, so it is necessary to contact a medical institution for diagnostic measures and laboratory tests.

Diagnostic methods for kidney disease

Diagnosis of kidneys and possible pathologies is carried out with the full consent of the treating doctor.

Also, during the initial examination, based on the patient’s complaints, an experienced doctor would already be able to draw up a clinical picture of the disease.

Based on the established diagnosis, the following diagnostic measures are prescribed:

• X-ray of the body and general condition of the body;
• performing an ultrasound (ultrasound analysis of the condition of internal organs);
• renal biopsy;
• excretory urography.

In addition, laboratory tests are also carried out;

• passing a general urine test;
• taking a general blood test;
• complete control over the human condition.

The most common form of the disease, with kidney pathologies, is heart disease.

Therefore, only complete control will be able to identify disturbances in kidney function and eliminate the consequences of this condition.

Self-medication for possible kidney diseases can lead to exacerbation and death for the patient.

Useful video

In modern medicine, ultrasound diagnostics of the kidneys is of particular importance. It is a minimally invasive procedure that allows you to accurately determine all the indicators of interest. These include the size, shape, even location of the organ. In addition, considerable attention during the study is paid to the ureter and bladder.

Thanks to such diagnostics, it is possible to accurately, quickly and effectively study almost all diseases of the urinary tract. The method allows you to evaluate blood flow, as well as evaluate its structure.

It is necessary to undergo an ultrasound if:

• A kidney ultrasound is prescribed by a doctor if some dangerous symptoms are detected. They may appear as a consequence.
• Improper functioning of the endocrine system. Various inflammatory processes that have a chronic or acute form; pain in the lumbar region.
• Urinary incontinence, characteristic pathological formations.
• Damage during trauma: genital organs with congenital pathology. It can be observed equally in both men and women.
• Suspicions of the presence of a number of inflammations that are a consequence of diseases.
• Ultrasound diagnostics can be recommended for patients who suffer from high blood pressure. Often it cannot be reduced, even using therapy prescribed by the doctor.
• The doctor may recommend that the expectant mother undergo an ultrasound examination during pregnancy. Such a recommendation may be the result of a number of complaints of progressive pain in the renal area.

Pregnancy is a factor that provokes the progression of existing ailments.

• Often, before applying for a job or during medical examination, doctors may recommend that patients undergo an ultrasound examination of the kidneys for preventive purposes.

Regarding contraindications, they do not exist, but despite this, some doctors prohibit ultrasound examination of the kidneys and bladder for those patients who have an inflammatory reaction and skin dermatitis. It often manifests itself in the lumbar region.

Before the procedure, a special gel is applied to the area under study. In some people, it is this that causes an allergy or inflammatory reaction, so such a reaction is considered a contraindication for ultrasound.

Kinds

Ultrasound is divided into two types:

1. Ultrasound echography. This view is based on the ultrasonic wave technique and its ability to demonstrate the outlines of tissues of varying densities. The study is used to diagnose deformations of renal tissue, with incorrect topographic location of the organ.
2. Ultrasound Dopplerography, it is also called the study of renal vessels. This method is based on changing the frequency and, accordingly, the wavelength of radiation. It consists of differences in reflected frequencies and formed blood elements. The study also takes into account the frequency of ultrasonic waves and the frequencies of the waves emitted by the device. The doctor conducts a visual analysis of the results being studied, thanks to this you can see the direction of blood flow.

What does an ultrasound show?

Thanks to ultrasound, you can immediately detect:

• Deformations and changes affecting the urinary system.
• Inflammatory processes.
• Various injuries.
• Anomalies resulting from abnormal intrauterine development.
• Diseases in the vascular system.

Norm for adults and children

It is difficult to determine normal indicators, because this term must be based on at least the age and gender of the person. Indicators that are considered relatively normal are equal to the following numbers: 40 - 50 x 50 - 60 x 100 - 120. The thickness, width and length of the organ are taken into account here.

Parenchyma thickness is a relative concept that changes with age.

The norm is considered to be indicators based on which the doctor excludes or confirms whether there is a structural pathology.

The following entries are also considered normal:

• The organ's external characteristics resemble a legume plant. The outside contour is outlined with straight lines.
• The kidney is located on the left above the right by several centimeters, the echo density of the renal pyramid is below the parenchyma.
• Hyperechoic capsule up to 0.15 cm thick
• The sinus of the kidney is equal in echo density to the tissue around the kidneys.
• Echogenicity. In the kidneys with the organ that produces bile, they are the same or the indicators may be significantly reduced.
• The phrase “Columns of Bertinius” or “partial enlargement of tissue” of the renal cortex is often used. These indicators should not bother the patient.
• The doctor should not visualize the collecting system.
• Normal anterior and posterior dimensions are up to 0.15 cm.
• The mobility of the organ during breathing is from twenty millimeters.
• The kidneys must be the same size, or one can be larger than the other by a maximum of 2 cm.
• In dense people, the kidney may not be completely visualized.
• The shape of the right adrenal gland resembles a triangular one, the left one resembles a moon.
• There is no clarity in the capsules.
• Even if the patient has tumors, they may not be visualized.

Also, the kidney ultrasound protocol has the following points:

• Structural anomaly. Here the doctor must emphasize whether there is a malignant formation, developmental anomalies, which consist in underdevelopment of tissue, cysts, or spongy structure of the kidney.
• Whether massive formations exist or not, their location is also displayed, echogenicity and echostructure are taken into account.
• Diameter and presence of stones. Their location and the presence of an acoustic shadow are also indicated.

Normal in children

If we talk about ultrasound of the kidneys in children, the indicators will be based on the age of the child himself.

Normal kidney size in cm for children:

Norm for pregnant women

Determined by the following parameters:

1. Where is it located? The normal location of the kidneys is on both sides of the spine. It is important that the level be taken into account: 12 thoracic and 1-2 lumbar vertebrae. The right kidney is often visualized slightly lower than the left;
2. Motor features. The organ can move, only these movements will be limited and only they are possible vertically. Increased mobility is considered a pathology;
3. Dimensions. This parameter is extremely important because it is based on changes that may indicate certain diseases. Most often they relate to the urinary system. So, if the organ is significantly increased in size, this may indicate inflammatory processes; neoplasms may develop in the kidneys. On the contrary, if the organ decreases, this symbolizes severe chronic illnesses, the kidney tissue is damaged or degenerative processes develop;
4. The renal pelvis should be free, there should be no sand or stones in it, all this symbolizes urolithiasis;
5. The fibrous capsule should normally be smooth.

What diseases can be detected by kidney ultrasound?

The main diseases that are detected by ultrasound are:

1. Kidney stone diseases.
2. Chronic and acute form of inflammatory kidney disease of bacterial etiology.
3. Kidney vessels with obvious defects, which leads to improper outflow of urine and blood supply to organs.
4. The cyst has a round shape and there is liquid inside.
5. Formations of malignant and benign type.

Interpretation of kidney ultrasound

To decipher the ultrasound results, here is a list of points that are considered during the examination:

• Parenchyma thickness

The concept under consideration is kidney tissue, which consists of microscopic formations, nephrons, which are a filtering element. The parenchyma is located on the surface of the organ, and inside you can find a cavity - a cup, which passes into the pelvis. The latter then becomes several times smaller and finds its continuation in the ureter. The thickness of the kidney tissue of a person who does not complain about his health. equal to 15 to 25 mm. When it increases, it symbolizes inflammatory edema; when it decreases, it symbolizes processes of a dystrophic type. In fact, the parenchyma often becomes thinner over the years. After 60 years, indicators may decrease by a centimeter per year, this is often considered the norm.

• Changes in the parenchyma

In the description of studies, such a concept as “increasing echogenicity” or “decreasing echogenicity” may be written. This symbolizes damage to the organ by some kind of ailment that has negatively deformed the dense tissue. Only a doctor must diagnose what exactly influenced such changes, because ultrasound will not indicate how much the echogenicity has changed. Often the parenchyma is affected by cysts - malignant formations that are filled with fluid inside; if they are small in size, do not develop further and do not harm the body or organ, there is no need to treat them. But when they actively develop, cause the manifestation of certain symptoms or are characterized by uncharacteristic external deformations, there is a possibility that this is no longer a cyst, but a tumor. Such a word as “tumor” can rarely be found in documents.

• Changes in the pelvis

They appear as compactions of the mucous membrane (symbolizes the inflammatory process). Also, their deformations symbolize the presence of stones or sand. Normally, the tissue of the organ being examined should be homogeneous, and there should be no sand or stones in the pelvis. Otherwise, it symbolizes urolithiasis. The main doctor should pay attention to the size of the stones (if any). This directly determines whether they can get out of the body on their own or whether certain procedures must be performed to do this.

Cost of the procedure

The cost of the procedure is based on the prestige of the clinic, the professionalism and certification of specialists, the quality of the equipment and its novelty. Below are the average price indicators; they can be significantly lower or higher:

• Moscow - from 1.5 thousand rubles.
• St. Petersburg - from 800 rubles.
• Ekaterinburg - from 500 rubles.
• Novosibirsk - from 1000 rubles.

Preparing for an ultrasound

There are special requirements at this stage. The main thing is to fill your bladder before the examination, so the patient should drink plenty of fluids an hour before going to the doctor.

An ultrasound scan of the kidneys allows you to accurately determine the presence or absence of a particular disease, which can negatively affect a person’s general condition.

You can also learn about kidney ultrasound from this video.

The size of the kidneys on ultrasound can be conveniently examined from the back. To bring out the upper pole of the kidney, ask the patient to take a deep breath. If you are obese, look for an acoustic window in the intercostal spaces along the anterior and posterior axillary lines. Newborns and young children can be scanned through the anterior abdominal wall.

Click on the picture to enlarge.

On a longitudinal section, the length (green) of the kidney is measured, as well as the thickness of the parenchyma (blue) - the distance from the capsule to the top of the pyramid, the thickness of the cortex (blue) - the distance from the capsule to the base of the pyramid. On the cross section, the height (pink) of the bud and the width (yellow) of the bud are measured.

Kidney size on ultrasound in adults

In an adult, the normal length of the kidney is 90-120 mm. If the patient is non-standard (very small or large), then the length of the kidney is calculated using the formula: 35 + 0.42 * height (cm). Often the left kidney is longer than the right. If the difference does not exceed 1 cm with a normal echostructure, it does not matter.

The width and height of the kidney are correctly measured using a transverse scan. In an adult, the normal space size is 30-50 mm, width 40-70 mm.

Length, width and height are in the ratio 2:1:0.8. When the shape of the kidney changes, this relationship is disrupted.

Some authors believe that kidney length depends little on body length; a more significant relationship is between kidney volume and body weight. Kidney volume (ml) is normally 300 cm³ or twice the body weight (kg) ± 20%. Kidney volume is calculated using the formula: Length*PZR*Width* 0.523.

The normal thickness of the kidney parenchyma is 15-25 mm. The normal thickness of the cortical layer is 8-11 mm.

The thickness of the parenchyma can be assessed by the ratio of parenchyma to sinus. On a transverse section at the renal hilum, the sum of the anterior and posterior parenchyma (blue) and the hyperechoic sinus between them (red) are measured. The normal ratio of parenchyma to sinus up to 30 years is >1.6; from 31 to 60 years - 1.2-1.6; over 60 years old - 1.1.

Kidney size on ultrasound in children

The length of the kidney in a full-term newborn is on average 45 mm. By 1 year it increases to 62 mm. Then every year the bud increases in length by 3 mm. A difference in length of up to 5 mm is allowed between the kidneys.

Table. Kidney size in children depending on height (M±σ) according to Pykov -

If physical development is delayed or accelerated, it is better to use the renal mass index. The specific gravity of the kidney is close to 1, so the volume is equal to the mass. The mass of the kidney is calculated using the formula: Length*Height*Width* 0.523. The ratio of total renal mass to body weight (in grams) is 0.04-0.06%.

Drawing. Healthy boy, age 7 years. Weight 40 kg, height 138 cm. On ultrasound, the length of the kidneys is 95 and 86 mm. The length of the kidney according to the formula = 62+3*6 = 80 mm, and according to the table, with a height of 138 cm, the upper limit of the norm is 90 mm. Renal mass index = (88.37+84.90)/40000 = 0.043. Thus, for nonstandard children, the renal mass index is preferable. Conclusion: The size of the kidneys corresponds to the weight of the child.

The thickness of the renal cortex in a newborn is 2-4 times less than the thickness of the pyramids. With age, this ratio tends to 1.

Sizes of the pelvis on ultrasound

The ureter, minor and major calyces are normally not visible on ultrasound. There are three types of location of the pelvis: intra-, extrarenal and mixed type. With an intrarenal structure, the lumen of the pelvis at an early age is up to 3 mm, at 4-5 years - up to 5 mm, in puberty and in adults - up to 7 mm. For extrarenal and mixed types of structure - 6, 10 and 14 mm, respectively. When the bladder is full, the pelvis can increase to 18 mm, but 30 minutes after urination it contracts.

Drawing. Regardless of the filling of the bladder, ultrasound shows a pelvis of mixed (1) and extrarenal (2) location, as well as under the fibrous bridge (3).

Take care of yourself, Your Diagnosticer!

Update: October 2018

Ultrasound examination is one of the most prescribed types of instrumental examination of human organs. This relatively young diagnostic method has a number of significant advantages:

• high information content;
• safety (can be carried out repeatedly);
• no side effects;
• well tolerated by the patient;
• not accompanied by painful discomfort;
• no contrast agent required;
• minimal preparation for the procedure.

Ultrasound occupies a leading position in the diagnosis of kidney diseases. There are 2 types of ultrasound diagnostics of the kidneys:

Ultrasound echography is based on the reflection of sound waves from the boundaries of tissues with different densities, and allows you to examine the renal parenchyma, detect conglomerates and neoplasms, as well as topographical disorders.
Doppler ultrasound based on the Doppler effect. Using the method, you can assess the state of blood circulation (changes in the direction of blood flow) in the vessels of the kidneys.

About the safety of ultrasound: back in 1979, the American Institute of Ultrasound (Bioeffects Committee) made a statement about the absence of adverse biological effects when performing ultrasound . And over the past quarter century, no reports of negative consequences of this procedure have been recorded.

This procedure does not use radiation, there are no negative effects at the site of contact of the skin with the sensor, there may be risks that depend on the individual health status of the patient, which should be discussed before the procedure with the attending physician. There are conditions that can make kidney testing difficult:

• significant obesity
• presence of gases in the intestines
• presence of barium in the intestines after a recent barium study

Preparing the patient for a kidney ultrasound

Preparation for a kidney ultrasound is simple, but plays an important role in the effectiveness of the study. The fact is that ultrasound does not pass through the air and gases that are present in the intestines. So, how to prepare for an ultrasound of the kidneys and adrenal glands?

3 days before the ultrasound you should:

• Eliminate from your daily diet foods that increase or provoke gas formation: brown bread, potatoes, fresh milk, cabbage and other raw vegetables and fruits, as well as sweets.
• Take enterosorbents for 3 days: white or black coal, espumisan, fennel. This will reduce gas formation.
• The evening before the test, you can have dinner with easily digestible food no later than 19:00.
• If only a kidney ultrasound is planned on the day of the study, there are no restrictions on food intake. If the entire abdominal cavity is examined, then you should not eat anything before the examination.
• If the bladder is also examined, it should not be emptied before the ultrasound. 1 hour before the procedure, drink 1.5-2 glasses of water, but if the bladder is too full by the time of the examination, you need to empty it slightly.
• Not all medical institutions provide disposable wipes for removing gel, so it is better to take a towel with you.

The special gel used during the procedure does not stain clothes, but it cannot be completely removed after an ultrasound, and it does not wash well, so it is better to wear not particularly smart clothes for the examination.

Indications for kidney ultrasound

What is a kidney ultrasound procedure?

• An ultrasound uses a device (transducer) that sends out high-frequency ultrasound waves so they cannot be heard. These waves, with a certain location of the transducer on the body, pass through the skin to the organs needed for examination. Supersonic waves are reflected from the organs like an echo and return to the transducer, which displays them in an electronic picture.
• The applied gel ensures more efficient movement of the transducer and eliminates the presence of air between the skin and the device, since the speed of ultrasound propagation is the slowest through air (the fastest through bone tissue).
• During a Doppler ultrasound of the kidneys, blood flow in these organs can be examined and assessed using special supersonic waves. Weak or absent signals indicate that there is an obstruction to blood flow within the blood vessel.
• Kidney ultrasound is successfully used during pregnancy or if the patient is allergic to contrast agents that are used during other studies.

In addition to ultrasound, the patient may be shown other studies: CT, renal angiography, renal radiography, antegrade pyelography.

Immediately before an ultrasound examination of the kidneys you should:

• Remove all jewelry, all clothing, and other objects that interfere with the study.
• The doctor may suggest wearing a special gown
• During the examination, you will need to lie motionless on your stomach, on your back and turn on your right and left sides.
• The doctor may ask you to hold your breath, inflate your stomach, and take a deep breath.
• A special gel is applied to the area to be examined, then using the ultrasound machine’s sensor, the doctor begins to examine the organs.
• The examination begins with the bladder and ureters, then the condition of the kidneys is assessed.
• If you need to evaluate blood flow, a whistle and noise will appear - this is how an ultrasound with Doppler is performed.
• The patient does not experience any discomfort during the ultrasound examination, except perhaps the sensation of a cool and moist gel.
• The duration of the procedure is 10-15 minutes.
• When examining a urinary tract, it is first examined in a full state, then an additional examination is carried out in an empty state.
• The gel is removed with a napkin immediately after the procedure.

The result of the kidney ultrasound is attached in the form of a black and white photo to the written report. If a pathology is detected (stones, cyst, tumor), it will be shown in the photo so that the attending physician can better understand the picture of the disease. If necessary, a video recording of the study can be attached to the conclusion.

What does a doctor determine when performing an ultrasound diagnosis of the kidneys?

During the examination, the doctor determines:

• location of the kidneys;
• shape and contours of the kidneys;
• kidney size;
• parenchyma structure;
• kidney blood flow;
• pathological formations such as stones, tumors, cysts, sand.

Ultrasound results - main indicators

Dimensions and topography

Normally, each kidney in an adult has the following parameters:

• length 10-12 cm
• width 5-6 cm
• thickness 4-5 cm
• parenchyma thickness ranges from 15-25 mm

The right and left kidneys may differ in size, but no more than 2 cm in any of the indicators. The shape of the bud is bean-shaped. Topographically, the kidneys are located retroperitoneally, on both sides of the spine at the level of the 12th thoracic, 1st and 2nd lumbar vertebrae, with the right kidney located slightly lower than the left. When breathing, the kidneys can move by 2-3 cm. The kidneys are enveloped in fatty tissue on all sides.

• A decrease in kidney size can be observed in chronic pathologies that occur with the destruction of renal tissue, as well as in other degenerative processes.
• An upward change in kidney size occurs in the presence of neoplasms, congestive processes and various inflammatory pathologies.
• A decrease in the size of parenchyma (kidney tissue) occurs with age, especially noticeably after 60 years.

Fabric structure

The structure of the kidney tissue is uniform or homogeneous, without inclusions. Cortico-medullary differentiation (visibility of the renal pyramids) should be clearly expressed. The renal pelvis - the cavity inside the kidney - should not contain any inclusions.

Changes in the structure of the kidneys occur in various diseases. The presence of formations inside the renal pelvis (sand, stones) indicates urolithiasis.

Let us separately dwell on the results of ultrasound of the adrenal glands - small but very important organs of the endocrine system. The adrenal glands may not be visualized in people with increased body weight. The right adrenal gland has a triangular shape, the left one has a semilunar shape, the echostructure of the organs is homogeneous.

Explanation of medical terms and concepts during ultrasound of the kidneys

It is difficult for ordinary people who do not have medical knowledge to understand the intricacies of medical terminology. Here is a breakdown of the main terms that may appear in an ultrasound doctor’s report. But you should not engage in self-diagnosis; this is solely the prerogative of the doctor.

Increased pneumatosis intestinalis

This term implies a pathological accumulation of gases in the intestinal cavity and indicates that the conditions for ultrasound diagnostics were unsatisfactory (poor preparation of the patient for the study). As a rule, this phrase is placed at the beginning of the conclusion. Most likely, the ultrasound will have to be done again.

Basic concepts (structural)

• Fibrous capsule- this is the outer membrane of the kidneys, which normally should be smooth, up to 1.5 mm wide and clearly visible.
• Parenchyma is the tissue of the kidneys.
• Pelvis- the cavity inside the kidneys in which urine coming from the kidney calyces is collected.

Terms characterizing kidney pathology

• Nephroptosis – prolapse of the kidney.
• Echopositive or mass formation. This term describes a tumor in the kidney.

If we are talking about a malignant formation, then the structure of the tumor is heterogeneous, has areas of reduced or increased echo density, echo-negative zones, and also an uneven contour. A benign tumor is described as a hyperechoic or homogeneous mass. When any neoplasm is detected, its location, shape, size, as well as the echogenicity and echostructure of the tumor tissue must be indicated. For kidney tumors, the diagnostic accuracy of ultrasound is 97.3%.

• Anechoic, space-occupying formation- cyst in the kidney. The location of the cyst, its shape, size and contents must be indicated.
• Microcalculosis, microliths- small stones or sand in the kidneys (up to 2-3 mm).
• Echoten, echogenic formation, conglomerate, hyperechoic inclusion - kidney stones. Their location, quantity, on which side they were detected, diameter and size, presence or absence of an acoustic shadow must be indicated.
• Increased or decreased echogenicity of renal tissue– change in tissue density due to disease or infection.
• Hypoechoic areas in renal tissue- tissue swelling (often observed with pyelonephritis).
• Hyperechoic areas in renal tissue- hemorrhages into the kidney tissue.
• Spongy kidney is a congenital cystic change in various structures of the kidney, giving it a spongy appearance.
• Enlarged renal pelvis– pathological condition, because Normally, the pelvis is not visualized. Occurs with obstruction of the urinary tract of various origins.
• Consolidation of the mucous membrane of the renal pelvis– pathological swelling of tissue of an inflammatory nature, often observed with pyelonephritis.

Of all echo-positive (solid) kidney tumors, renal cell carcinoma is considered the most common (85-96%). Benign tumors - adenoma, oncocytoma, leiomyoma, angiomyolipoma, etc. account for 5-9%.

Kidney ultrasound is a simple test that anyone can undergo as prescribed by a doctor or at their own request. It is carried out both on a budgetary basis and for a fee, in public and commercial medical institutions that have ultrasound equipment. The price of an ultrasound examination of the kidneys varies depending on the region, from 400 to 1200 rubles.