What size should kidneys be normally? Normal kidney sizes on ultrasound in adults and children - explanation.
Kidneys are unique organs. During the day, they manage to pass all the blood through themselves hundreds of times and thereby cleanse it from harmful substances, and their health can be assessed by measuring their basic parameters during an ultrasound. Therefore, based on whether the size of the kidney is normal, one can judge its performance.
Everyone has it healthy person there are 2 kidneys that are located inside abdominal cavity in the lumbar region. Each of them is bean-shaped and weighs about 150–200 g. However, usually left kidney slightly larger than the right, which is explained by the presence in the right half of the body of a fairly large liver, which somewhat impedes vertical growth right bean-shaped organ.
In some cases, even at the stage of intrauterine development, disruptions in the formation of internal organs occur, so sometimes people are born with 1 kidney or, conversely, with double the number of them. But, as a rule, this in no way affects the quality of functioning of the whole organism and its congenital defects development, patients learn when undergoing ultrasound examinations for completely different reasons.
Each kidney consists of certain structural elements, the size, clarity of boundaries and shape of which are important diagnostic value. This:
- The connective tissue capsule and serous membrane that cover each of these paired organs.
- Parenchyma. It is formed by the cortex and medulla. In addition, the parenchyma contains epithelial tubules and special renal corpuscles, which together with numerous blood vessels form nephrons.
- Near the nephrons is a funnel-shaped cavity called the pelvis.
- The pelvis smoothly passes into the ureter, through which urine already formed in the nephrons is discharged into the bladder, and then into the external environment.
Important: each kidney has about 1 million nephrons, which are their structural units.
Kidney structure
In addition, an important parameter in assessing the quality of work of these organs is the patient’s age, since the size of an adult’s kidney remains relatively stable between 25 and 50 years. Therefore, if until the age of 20 or even 25 these organs continue to increase, then after the 50th anniversary there is usually a decrease in their size.
Also, the size of the kidneys is directly proportional to a person’s body mass index. Therefore, as BMI increases, the size of each of the body’s main filters also increases.
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But the most important evaluation parameter is not so much the size of each of the kidneys, but their ratio. Normally, the difference between the size of the right and left kidney should not exceed 1.5 cm.
In a healthy adult, the kidney has the following parameters:
- length – 80–130 mm;
- width – 45–70 mm;
- thickness – 40–50 mm.
Attention! Traditionally, the length of the kidney corresponds to the height of the 3 lumbar vertebrae, but in any case the ratio of length to width is always 2:1.
As for children, then for kids different ages other values are typical. So, the average length of a bud is:
- 0–2 months – 49 mm;
- 3–12 months – 62 mm;
- 1–5 years – 73 mm;
- 5–10 years – 85 mm;
- 10–15 years – 98 mm;
- 15–19 years old – 106 mm.
Important: since all children develop differently, it is difficult to accurately establish normal limits for them, therefore, for the most reliable assessment of the condition of the kidneys, when measuring their size, be sure to take into account the child’s weight, height and body type.
Hypertrophy may indicate the development of diabetes mellitus, but is sometimes a normal variant
To diagnose a number of pathologies, doctors need to assess the thickness of the parenchyma. In healthy young people, the normal size of the kidney parenchyma ranges from 15 to 25 mm. But since various degenerative processes occur in it over the years under the influence of certain diseases in older people, its thickness, as a rule, does not exceed 11 mm.
Important: in an ordinary healthy person, the size of the kidney is no different from the size of the fist.
Thus, ultrasound can be used to assess the condition of the kidneys. But there is no time to delay in carrying out this painless, accessible and highly informative study, since the sooner the pathology is identified, the greater the chance a person will have that his natural “filters” will be completely restored.
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The human kidney is a unique paired organ that continuously cleanses the blood of substances harmful to the body. human body. The size of the kidney is normal - this is one of the most important diagnostic parameters. They vary depending on age, gender and body mass index.
Let's look at the main structural elements kidneys:
- The kidney is covered with a thin connective tissue capsule and serosa(front).
- The kidney parenchyma consists of the cortex and medulla. The cortex is located in a continuous layer under the renal capsule. The medulla is 10-18 conical pyramids with medullary rays located at the base, growing into the cortex. The renal parenchyma is represented by epithelial tubules and renal corpuscles, which together with blood vessels form nephrons (up to 1 million in each kidney).
- The structural unit of the kidney is the nephron.
- The funnel-shaped cavity that receives urine from the nephron is called the pelvis.
- The organ that receives urine from the renal pelvis and transports it to the bladder is called the ureter
- The blood vessel that branches from the aorta and brings blood contaminated with waste products to the kidneys is called the renal artery, and the vessel that delivers filtered blood to the vena cava is called the renal vein.
What factors influence kidney size?
Numerous studies have found that the thickness, width and length of the cortical layer, as well as the size of the kidney in men are much larger than in women. This is due to the fact that representatives of the stronger sex have body sizes that exceed those of the female body.
At the same time, the researchers found an insignificant difference between the lengths of the right and left kidney (the left kidney is on average 5% larger than the right). According to experts, the vertical growth of the right kidney is hampered by the liver.
Also, the size of an adult’s kidney is greatly influenced by age. The kidneys “grow” until the age of twenty to twenty-five, then they remain relatively stable throughout middle age, and after fifty years they begin to decline.
During the research, it was found that kidney size is closely related to body mass index (BMI). As BMI increases, not only the size of the kidneys increases, but also their volume, height and height.
Note: with the development of hypertension or diabetes mellitus, renal hypertrophy develops.
The longitudinal size of the kidney of an adult is on average 100-120 mm (more precisely, from 80 to 130 mm). As a rule, the length of the kidney corresponds to the height of three lumbar vertebrae, the width is in the range of 45-70 mm, and the thickness is 40-50 mm.
Note: no matter what size the bud is, its length to width ratio is 2:1.
In young people, the normal size of the kidney parenchyma (its thickness) ranges from 15-25 mm. With age, as a result of atherosclerotic processes or inflammation, its thinning occurs, and in people over sixty years of age, the thickness of the parenchyma often does not exceed 11 mm. To assess the structure of the kidney in clinical practice The parenchymopyelic index is used.
I would like to note that the size of a healthy person’s kidney does not exceed the size of his fist.
Kidney structure
Kidney size in children
It should be noted that all children develop differently, and therefore difficulties arise in determining the size of the kidneys in childhood. However, during research, scientists were able to determine average length kidneys based on age:
- From birth to two months, the kidney size is 49 mm;
- From three months to one year – 62 mm;
- From one to five years – 73 mm;
- From five to ten years – 85 mm;
- From ten to fifteen years - 98 mm;
- From fifteen to nineteen years - 106 mm.
With more precise definition The size of a child’s kidney takes into account his weight and height.
Interesting fact: Babies have kidneys, relative to body weight, that are three times larger than adults.
The main function of the kidneys is to cleanse the blood of waste and toxic substances. The most harmful waste products of the human body are urea and uric acid. Cluster large quantity These substances cause the development of numerous severe pathologies, and this can also lead to death. During the filtration process, the renal parenchyma cleanses the body of waste (they are collected in the pelvis and transported to the bladder).
An interesting fact: the kidney parenchyma manages to completely cleanse the blood about fifty times per day.
The main functions of the kidneys include:
- Urine formation. Thanks to the kidneys, excess water, organic and inorganic substances, as well as nitrogen metabolism products and toxins;
- Maintaining normal water-salt balance(due to fluid excreted in urine);
- Regulation blood pressure(due to the secretion of renin, excretion of water and sodium, as well as depressor substances);
- Regulation of pH levels;
- Hormone production;
- Vitamin D production;
- Regulation of hemostasis (formation of humoral regulators of blood coagulation, as well as participation in heparin metabolism);
- Regulation of erythropoiesis;
- Metabolic function (participation in the metabolism of proteins, carbohydrates and lipids);
- Protective function (removal of foreign and toxic substances from the body).
Note: with the development of various pathological conditions renal excretion is often impaired medicines, and therefore patients may experience side effects and even poisoning.
In most cases, ultrasound examination can be called fully informative and sufficient method diagnostics in order to determine kidney disease and prescribe adequate treatment, including excluding pathologies during screening examinations. The price of a kidney ultrasound is quite reasonable; it must be clarified at the reception desk of the medical institution.
An ultrasound examination device allows the doctor to determine several important parameters during examination: the state of blood flow, the size of the organ, signs of inflammatory processes, the state of the parenchyma structure, the presence of stones in the cavities, as well as malignant or benign neoplasms. 
Let's consider these parameters in more detail.
In this article we will understand how to decipher an ultrasound of the kidneys.
The norm for a person is to have a pair of kidneys, but anomalies can also be found. May be congenital absence one of them is the so-called agenesis (unilateral aplasia). Or the kidney could be removed through surgical intervention. You can also find congenital organ duplication, most often it is unilateral. 
The normal location of the kidneys can be called their location on at different levels each other relative to each other. The right one, D, is located at the level of the 2nd lumbar vertebra and the 12th thoracic, and the left, L, is located at the level of the 1st lumbar vertebra and the 11th thoracic.
An ultrasound examination of a woman’s kidney helps to identify nephroptosis (prolapse) or dystopia, that is, its atypical location in the pelvis. The normal shape of the kidney is bean-shaped with an even contour and clear viewing fibrous capsule, which is the outer shell of the organ. Normal sizes for pregnant women are different, since during this period the kidney lengthens by two centimeters. A slight expansion of the pelvis and ureter is also permissible.
The physiological norm for the size of the kidneys in an adult is 40-50 mm in thickness, 50-60 mm in width, 100-120 mm in length. However, these indicators may vary slightly depending on the gender and height of the patient.
The thickness of the parenchyma layer is another important parameter when interpreting kidney ultrasound. The norm is 18-25 mm. Nevertheless this indicator depends on the age of the person. For older people, it may be reduced to 11 mm, which is associated with sclerotic changes. Parenchyma is the tissue in which nephrons, structural and functional units, are located. If its thickness increases, this may indicate inflammation or swelling of the organ, and if it decreases, then we can talk about its dystrophy.
An ultrasound scan of a newborn baby is necessary if high probability abnormal development he has internal organs due to heredity, difficult pregnancy and childbirth, changes in the baby’s urine. Ultrasound of the kidneys for older children is prescribed after detecting abnormalities in tests, with complaints of pain in the lower back or lower abdomen, due to injury, or with urination problems.
In children, the size of the kidneys depends on height and age. If the height is less than 80 cm, then only 2 parameters are measured: the width and length of the organ. In a child over 100 cm, the thickness of the parenchyma is also measured.
Kidneys increase in size when acute glomerulonephritis or pyelonephritis, as well as in case of loss of pairing, since in this case the organ will experience increased functional load.
When decoding an ultrasound of the kidneys, the norm is to clearly identify the boundaries of the pyramids of the parenchymal layer. Their echogenicity should be lower than that of the parenchyma. If such a difference is not detected during examination, this may indicate hydronephrosis.
This indicator determines the condition and structure renal tissue, which is normally homogeneous.
Echogenicity is the degree of intensity of reflection from tissues sound wave. The reflection is more intense and the image on the monitor is lighter when the parenchyma is denser. In low-density tissues, echogenicity is weak, with visualization in the form of dark areas.
Air and liquids are anechoic. For example, a cavitary cyst containing fluid is described by a specialist as an anechoic formation. Sclerotic processes, on the contrary, are characterized by hyperechogenicity.
The collecting system or cavitary system is responsible for performing the function of collecting urine. Using kidney ultrasound, men are diagnosed the following types changes in it: the presence of calculi (sand, stones), pyelonephritis (inflammatory compaction of the mucous membrane of the pelvis). Also expansion of the ChLS may indicate calicoectasia, pyelectasia, tumors, ureteral obstruction and hydronephrosis.
The norm for the pyelocaliceal system is its anechoicity. Stones whose size is 4-5 mm or more are described by ultrasound as an echogenic formation, hyperechoic inclusion, or echogenicity. The presence of sand in the organ is called microcalculosis.
To visualize the blood vessels of an organ, duplex scanning is used, in which the ultrasound scanner produces information in a spectral graph or color image. This technique is painless and non-invasive. Therefore, it can be used when examining kidneys in children. Ultrasound determines the condition of the walls of blood vessels, the presence of stenoses and intravascular obstructions, as well as the speed of blood flow. Its normal variation is from 50 to 150 cm/sec.
For the color scheme, dark tones are considered normal, and bright colors indicate accelerated blood flow, indicating the presence of stenosis, the main symptom of which is an increase in velocity in the renal artery (200 cm/sec). The blood flow resistance index is also determined, which depends directly on the person’s age. The older the patient, the higher it is. For the renal artery, the normal value of the resistance index is 0.7, and for the interlobar arteries - 0.34-0.74.
Ultrasound is also used to confirm kidney injury. There are 5 categories of injuries to this organ. They differ in the degree of violation:
- the organ is minimally damaged, there are no ruptures (detection of a subcapsular hematoma of the kidney);
- the cortex is torn;
- the cortex is torn by more than a centimeter, while extravasation of contrast is not observed;
- the ureteropelvic segment is disrupted;
- the vascular pedicle is damaged or it is torn off from the vessels and ureter.
Interpretation of kidney ultrasound, the norms of which are given above, should be carried out by a urologist. The conclusion is usually accompanied by a sonogram or an attached ultrasound photo, on which arrows mark the place where the pathological changes. If upon detection vascular changes or tumors, an ultrasound video will be attached, this will help make the correct diagnosis.
The most informative is ultrasound diagnostics upon detection of diseases such as damage to the renal vessels, nephroptosis, amyloidosis, narrowing of the ureters, organ degeneration, abscesses, cysts, tumors, hydronephrosis, stone formation, inflammatory processes(glomerulonephritis, pyelonephritis).
When the ultrasound report indicates “severe intestinal pneumatosis,” this means that the examination was uninformative due to flatulence. In this case, the ultrasound will need to be repeated, having previously prepared, that is, by drinking carminative drugs.
Price this study depends entirely on the chosen clinic and region. If an ultrasound is performed on the direction of a doctor, it can be free. In private specialized center in Moscow average price ranges from 500 rubles to 3500. In the regions, the cost will be slightly lower, but not significantly. You can pay for research from 350 rubles to 2500.
From this article you learned about ultrasound, the norms of its indicators, as well as kidney disorders that can be detected during the examination.
At the moment, one of the frequently prescribed diagnostic methods that determine the condition of the kidneys is ultrasound examination. Kidney ultrasound results will help determine possible diseases organs or pathological manifestations. With help ultrasound examination determine the following parameters: quantity, localization, contours, shape and size, structure of parenchymal tissue. It is determined whether there are neoplasms, stones, inflammation and swelling. Renal blood flow is visualized.
Indications for an ultrasound scan include: difficulty urinating, the appearance of blood in the urine, pain in the lumbar region, injuries, existing inflammatory processes, poor urine analysis.
Kidney ultrasound allows you to examine the health or progress of the organ’s disease, selecting appropriate therapy based on the data obtained.
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Diagnosis of kidney condition does not differ between people of different genders. The norms of indicators are the same for both men and women. Normal sizes kidneys in women are different during pregnancy. The norm is considered to be lengthening of the organ up to 2 cm; slight expansion is allowed along with the pelvis and ureters. The norm for adults when decoding the results is as follows: thickness - 40-50 mm, length 100-120 mm, width 50-60 mm, thickness of the functional part - 15-25 mm. The sizes of the right and left kidneys differ, but not more than 2 cm. The normal ultrasound scan of the kidneys in an adult is determined by the height indicator. Using the table below, you can determine the normal size of the kidneys relative to a person's height.
| Height | Length, mm | Width, mm | Parenchyma thickness, mm | |||
| Left | Right | Left | Right | Left | Right | |
| 150 | 85 | 82 | 33 | 29 | 13 | 13 |
| 160 | 92 | 90 | 35 | 33 | 14 | 13 |
| 180 | 105 | 100 | 38 | 37 | 17 | 15 |
| 200 | 110 | 105 | 43 | 41 | 18 | 17 |
The size of the kidneys and adrenal glands is one of significant indicators normal development organs. Each person has individual anatomical features, expressed in terms of height, body weight, body type, and age characteristics. Based on these indicators, standards have been developed that help assess pathology or normal state organ.
What are the kidneys and adrenal glands?
The kidneys are a paired organ that cleanses the body. During the day, they pass blood through themselves hundreds of times, cleansing it of waste and toxins. The human body, as a rule, has 2 kidneys located in the abdominal cavity at the lumbar level. They resemble beans in shape, each weighing about 150–200 g. There is an asymmetry in the size of the kidneys: the left one is larger than the right one, since the liver interferes with the growth of the latter.
Sometimes a child is born with one kidney, or their number doubles, which does not affect normal functions. Usually, the patient accidentally becomes aware of a deviation in the structure urinary system when examining for any indication using ultrasound.
Asymmetry is also observed in appearance adrenal glands, which are located above the upper ends of the kidneys. The right adrenal gland has a triangular shape with rounded corners, the left one resembles a crescent. The adrenal gland is covered with a fibrous capsule, which is adjacent to the cortex, which includes 3 zones: glomerular, fascicular and reticular.
The following structural elements are distinguished:
- Connective tissue capsule.
- The serous membrane covering each organ.
- Parenchyma with epithelial tubules and nephrons, the number of which reaches 1 million.
- The pelvis is a funnel-shaped cavity that passes into the ureter.
Urine formed in the nephrons exits into the bladder.
Kidney size assessment
Women's kidneys are smaller than men's due to the significantly lower body weight of representatives of the weaker half. The age of the patient is of great importance in determining the size of the kidneys: up to 25 years, they increase, after which their growth stops until 50 years, after which a decrease in the organ is noted.
Adult kidney size is directly proportional to body weight
Anatomical indicators
It is possible to compare the normal size of the kidney with the patient’s parameters using an ultrasound examination, which makes it possible to determine the size of the organ and identify diseases that accompany an increase in the size of the kidneys.
Standard indicators healthy kidney in adults it is considered:
- Thickness – 40–50 mm,
- Width – 50–60 mm,
- Length – 100–120 mm
Normal average the thickness of the parenchyma of an adult is 23 mm. As the body ages, the parenchyma decreases by a maximum of 2 times. During the day, the kidneys cleanse the blood more than 50 times. When the human body grows, circulatory system and the amount of blood also increases. This causes an increase in the size of the kidneys, which corresponds to the norm for adults.
Deviations in kidney size
If the renal size does not correspond to the norm, it is necessary to undergo an examination immediately, since, most likely, this indicates the presence of pathology.
The size of the kidney may exceed the norm in the absence of another, when the first one has to perform double functions.
An increase in kidney size may indicate serious pathologies various kinds, especially such as hydronephrosis. With hydronephrosis, a concentration of formed urine occurs in the pelvis, which moves through the ureter to the bladder. Hydronephrosis is expressed by stagnation of urine, which leads to an enlargement of the pelvis, and then the most important filter of the body.
Indicators of kidney size in children
Development process child's body in each case it occurs differently, and it is not easy to establish normal renal values. To recognize disease processes, standards have been established taking into account the average statistical indicators of kidney size in children.
Table of dependence of kidney size on human height
The kidneys of newborn babies up to 2 months measure 49 mm, the pelvis of a newborn is 6 mm and until the age of three it increases by only 1 mm. U one year old baby the organ is 62 mm. During the development of the human body up to 19 years renal enlargement occurs every 5 years on average by 13 mm.
By correlating real indicators and normal parameters, it is possible to identify serious pathologies urinary system child.
About the adrenal glands
The adrenal gland has an uneven surface. The medulla is located in the center of the organ large cells, to which chromium salts give a yellowish-brown color: epinephrocytes, which produce adrenaline, and norepinephrocytes, which produce norepinephrine. With the help of adrenaline, glycogen is broken down, the amount of which becomes smaller in the muscles and liver.
The hormone increases the percentage of carbohydrates in the blood, and the work of the heart muscle becomes stronger and faster. Adrenaline makes the lumen of blood vessels less narrow, and blood pressure increases. Norepinephrine has a similar effect on the body, but sometimes the hormones cause the opposite effect: under the influence of norepinephrine, the heart slows down.
Adrenal parameters
The adrenal gland of an adult weighs at least 12 g, length – 40–60 mm, width – up to 30 mm, thickness – 4–7 mm. Some people are born with only one adrenal gland. The adrenal gland of a newborn weighs a maximum of 7 g, and this is almost twice as much as the mass of the organ of a one-year-old child.
This is explained by the fact that the mass of the organ has decreased due to the thinning of the cortex, which is in the process of restructuring. By the age of five, the mass of the adrenal glands returns to the initial value, after which it gradually increases. The cortex of the organ is formed by the age of 12.
By the age of 20, the weight of the adrenal gland becomes greater, the maximum size indicators are reached - up to 13 g. In the future, neither the size nor the mass of the adrenal tissue undergoes changes. In female adrenal glands there are few big sizes compared to men's. During pregnancy, the adrenal gland enlarges by 2 g.
In the eighth decade, there is a decrease in the mass and size of the organ.
The adrenal glands are located asymmetrically: the left one is slightly behind the right in size and weight
Determining the size of the kidneys and adrenal glands using ultrasound
Ultrasound examination makes it possible to assess the size and structure of organs, the clarity of their contours, and the presence of neoplasms. An ultrasound examination is carried out if there are symptoms indicating various pathologies of the adrenal glands:
- The skin darkens.
- Feeling of unreasonable fatigue.
- Rapid weight gain.
- Formation of stretch marks on the skin.
- Heavy hair growth in women, disruption of the menstrual cycle.
- Sexual impotence in men.
When the adrenal glands are normal, small triangles are visible on ultrasound. Sometimes the sizes of organs may differ; in half of the cases the left adrenal gland is not visible, in 10% of studies the right one is not visible. The size of the adrenal gland should be below 2.5 cm. If this limit is exceeded, suspicions arise about the presence of a disease, in similar cases Additional research is being carried out.
A slight deviation of the indicators from accepted standards is allowed by a maximum of 10 mm. Exceeding the norm by 1 cm for any parameter should cause the doctor to find out the reasons for the changes that have occurred in the urinary system.
At chronic inflammation renal sizes decrease. Acute inflammatory processes and oncological tumors lead to enlargement of the organ. A change in the size of the organ is observed with unilateral or bilateral nephroptosis. The disease has 3 degrees, which differ in the level of reduction of the kidney edge:
- 1 tbsp.
- – the organ descends to the height of one and a half lumbar vertebrae.
- 2 tbsp.
- 2 or more vertebrae.
3 tbsp. – for 3 or more vertebrae.
Parenchyma is capable of changing thickness during disease processes. Pyelonephritis, nephropathy, hypertension lead to a decrease in the thickness of the parenchyma and the formation of compaction. Ultrasound examination makes it possible to note how the echogenicity of an organ changes. Ultrasound examination makes it possible to determine not only the size of organs, but also their location and the presence pathological formations
The kidney structures have unequal density, which may differ from the norm, which indicates disease. Echogenicity changes in the presence of cystic growths. If the kidney or adrenal gland is affected malignant neoplasm, the size and shape of the organ will have uncharacteristic echo density.
Ultrasound examination of organs –
- safe procedure
- . It also does not pose a threat to the fetus, so it is used during pregnancy. The accuracy of ultrasound diagnostics is high. The patient has stones larger than 2 mm, which are detected with almost 100% accuracy.
- This can determine whether the stones can pass without surgery. The results of an ultrasound examination of the kidneys and adrenal glands are interpreted by the attending specialist, who, in order to prescribe appropriate therapy, must take into account the peculiarities of the course of the disease of a particular patient.
Human kidney anatomy Standard Kidney Growth Indicators Factors that influence sizes- This is a special paired organ, the functions of which cannot be taken over by other systems.
They cleanse the body of harmful substances by driving blood through themselves. What size should the kidneys be? The size of the kidneys is one of the main indicators when establishing a diagnosis for various
kidney diseases . Normal sizes may vary depending on the age and gender criteria and the person’s weight.. This component excretory system, being a paired organ, is projected differently to other organs. The right component of the system is adjacent to the adrenal gland and liver. The left component is in contact with the adrenal gland, stomach and spleen. At the back, both organs are adjacent to the diaphragm.
Each of these elements of the excretory system is covered on top special capsule of connective fibers and a serous accessory membrane. The renal parenchyma is formed from the medulla and cortex. The first is approximately 15 pyramids of a conical type with rays at their base. These rays grow into the continuous cortical shell.
Each kidney contains up to 1 million nephrons. They are the main constituent units of these components of the human excretory system. They are formed from tubules, corpuscles and passing blood vessels.
The pelvis is a special cavity that receives urine. The ureter receives urine from the pelvis and then sends it to the bladder.
The renal artery is a blood vessel that arises from the aorta. He brings polluted blood. The renal vein is a blood vessel that carries pure blood to the main vein.
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Standard Kidney Growth Indicators
The longitudinal size of the organ should be approximately from 80 to 130 mm. In an adult, the length of this internal organ must correspond to the height of three vertebrae lumbar region. The width for men can be up to 70 mm, and the thickness up to 50 mm. For any size, the ratio of length to width should correspond to a clear ratio of 2:1. Since all parameters of height and weight of the stronger sex are often greater than those of women, the size of this component of the excretory system is smaller in the weaker sex.
If we compare the dimensions of human parenchyma with standards, then the thickness should be no less than 15 mm and no more than 25 mm. With increasing age and the development of inflammatory and atherosclerotic processes, the parenchyma may become thinner. In most cases, after 60 years of age, the patient's parenchyma decreases to a size of 11 mm.
To find out all the dimensions of this component of the excretory system, ultrasound is used. If we summarize the information about the structure and size, then with relatively good health the kidneys are approximately the size of a fist.
In childhood, some difficulties arise in determining the standardization and normalization of renal parameters due to the fact that children grow and develop individually. To determine the norm, you need to know the weight and height of the child. Approximate values are as follows:
- in infants it will be 50 mm;
- at 2-3 months it reaches 63 mm;
- at 5 years – 75 mm;
- at 10 years – 85 mm;
- at 15 years old the value is 98 mm;
- 20 years – 105 mm.
An interesting phenomenon is that an infant has a size to weight ratio that is 3 times greater than an adult.
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Factors that influence sizes
In general, the size of the kidneys is affected by a person’s gender, age and weight. Scientists have found that a person's mass index affects overall size, volume, height and height.
It was found that the right organ is smaller than the left, which is due to the fact that the liver prevents its growth.
The size of the organ can increase up to 25 years, after which it stops growing, but after 50-60 years it begins to decrease in size.
At diabetes mellitus or hypertension, renal hypertrophy may occur.
It is very important to monitor the size and functioning of the renal structures, because this paired organ has great importance For normal functioning the entire human body.
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 deep breath. In case of obesity, 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, this does not matter.
The width and height of the kidney should be correctly measured when transverse scanning. In an adult, the normal width of the kidney is 40-70 mm, and the height is 30-50 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) should be twice the body weight (kg) ± 20%. Kidney volume is calculated using the formula: Length*Height*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 -
When lagging or accelerated physical development 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 is in early age 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 filling 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!
The kidney test will help detect structural and anatomical changes in the urinary organs that are characteristic of a particular disease.
The standards of indicators that are examined during the procedure differ in the norms for adults and children. An ultrasound of the kidneys will help the doctor see such standard set
- indicators and parameters as:
- number of organs;
- location of the kidneys;
- dimensions;
- shape and contours;
- structure of the renal parenchyma;
blood flow condition.
Quantity
- Normally, a person should have two kidneys, but there are also anomalies that may be associated with
- congenital absence;
- duplication of one of the organs;
removal of a kidney due to surgery.
Location The kidneys are located quite high, at the level of the first and second lumbar vertebrae. Fine right kidney
is located slightly above the left - this is due to the fact that it is pushed upward by the liver. A kidney that is too drooping is considered a deviation from the norm.
Location of the kidneys (dorsal view)
Dimensions
- For adults, the normal kidney sizes are:
- length – 100-120 mm;
- width – 50-60 mm;
thickness – 40-50 mm.
- In children with:
- height up to 80 cm - only length and width are determined;
height above 100 cm - all indicators are measured.
Inflammatory processes such as pyelonephritis or glomerulonephritis can increase the size of the kidneys and increase the risk of organ loss.
Shape and contours Form normal kidney
bean-shaped and has clear, even contours. In some cases, a “humpbacked” or “lobed” kidney may be the norm. Most often, these are congenital anomalies associated with abnormalities in the structure of the organ, which do not require treatment, provided the patient does not have any associated ailments.
- It is also possible to identify the following features of the organ:
- uneven contours;
- changes in shapes, pelvis and cups;
kinking of the ureter.
Anatomically, the appearance of the kidneys resembles beans with slightly rounded poles, upper and lower
Structure of the renal parenchyma
Normally, the structure should be uniformly porous. If the kidneys are affected by the disease, then this parameter in the ultrasound interpretation can be described as “increased echogenicity” or “decreased echogenicity.”
In the parenchyma there may be cysts - bubbles with fluid. They are not treated if they are small and do not change in size over time. If they cause symptoms or are unusual in appearance, a tumor may be present.
Blood flow condition
A detailed diagnosis of blood vessels is most easily obtained using Doppler.
- The Doppler ultrasound method allows you to determine:
- the presence of stenoses and intravascular obstructions;
- blood flow speed (normally from 50 to 150 cm/sec).
Visualization of renal blood flow. Dark colors are considered normal, bright colors are an increase in the speed of blood flow. This indicates the presence of stenosis, in which the blood flow speed can reach 200 cm/sec.
Ultrasound indicators and their standards are described in the video. Provided by the channel “Clinic of Aesthetic Gynecology”.
What does an ultrasound show and why is it done?
Ultrasound makes it possible to identify pathologies such as:
- formations on the kidneys (tumors benign and malignant);
- diffuse change or damage to the renal parenchyma;
- urolithiasis (kidney stones);
- nephroptosis (organ prolapse);
- inflammatory diseases, acute and chronic (pyelonephritis, as well as changes in glomerulonephritis);
- hydronephrosis;
- MKD (urolithiasis) of the kidneys;
- blockage of the ureters and expansion of the renal pelvis;
- congenital anomalies of the structure of the kidney and the blood supply system of an underdeveloped organ;
- cysts of various etiologies and localization;
- pyeelectasis in childhood;
- kidney abscesses;
- kidney tuberculosis.
Kidney changes can be diagnosed and recognized using laboratory tests, but ultrasound examination allows us to diagnose accurate diagnosis. With its help, you can observe changes in the state of organs over time, and use the results obtained during the pre- and postoperative period.
Normal indicators
For adults and children, the ranges of normal kidney health indicators are different. There were no differences between the normal readings in men and women. Based on the special condition, the norms for pregnant women differ from the usual ones.
In adults
Normal indicators in the structure of the kidneys in adults are shown in the table:
| Height, cm | Length, mm | Length, mm | Width, mm | Width, mm | Parenchyma thickness, mm | Parenchyma thickness, mm |
| Left | Right | Left | Right | Left | Right | |
| 150 | 85 | 82 | 33 | 29 | 13 | 13 |
| 160 | 92 | 90 | 35 | 33 | 14 | 13 |
| 180 | 105 | 100 | 38 | 37 | 17 | 15 |
| 200 | 110 | 105 | 43 | 41 | 18 | 17 |
In children
The norms for children are given in the table:
| Age | Right | Right | Right | Left | Left | Left |
| Thickness, mm | Length, mm | Width, mm | Thickness, mm | Length, mm | Width, mm | |
| 1-2 months | 18,0-29,5 | 39,0 — 68,9 | 15,9-31,5 | 13,6-30,2 | 40,0-71,0 | 15,9-31,0 |
| 3-6 months | 19,1-30,3 | 45,6-70,0 | 18,2-31,8 | 19,0-30,6 | 47,0-72,0 | 17,2-31,0 |
| 1-3 years | 20,4-31,6 | 54,7-82,3 | 20,9-35,3 | 21,2-34,0 | 55,6-84,8 | 19,2-36,4 |
| up to 7 years old | 23,7-38,5 | 66,3-95,5 | 26,2-41,0 | 21,4-42,6 | 67,0-99,4 | 23,5-40,7 |
Acceptable standards for pregnant women
If the results of an ultrasound scan of pregnant women show that the organ is elongated to 2 cm or there is a slight expansion (with the pelvis and ureter), this is normal.
What diseases does ultrasound detect?
Conducting and interpreting a kidney ultrasound will help identify the following diseases:
- inflammation of the bladder (cystitis);
- inflammation of the kidney (nephritis);
- inflammation of the renal pelvis (pyelonephritis);
- kidney cyst;
- salts, stones, sand in the kidneys and bladder;
- tumors;
- vascular disorders in the kidneys.
Traumatic injuries
Kidney damage implies a violation of the integrity of the organ due to physical impact. Differs in severity: from minor injuries to posing a threat for human life.
In medicine, there are two types of injuries - closed and open injuries kidney
Closed damage
These include:
- bruise (there may be hemorrhages in the parenchyma, but there is no rupture of the hematoma);
- contusion;
- subcapsular rupture, with a hematoma present;
- crushing;
- separation of the ureter, complete or partial damage to the vascular pedicle (rupture of tissue and fibrous capsule of the kidney).
Open damage
Reasons open damage can be:
- gunshot wounds;
- knife wounds;
- possible damage to the abdominal cavity with subsequent development of peritonitis.
Photo gallery
Bruise (hematoma) of the kidney Kidney crush Kidney injury
Interpretation of kidney ultrasound results
To decipher the kidney ultrasound indicators, it is better to contact a specialist who will also take into account the patient’s medical history as a whole.
Special terms in the conclusion
The ultrasound report contains special terms that are incomprehensible to most patients:
- Severe pneumatosis of intestinal loops. This means that the study was difficult due to the large amount of gases in the intestines.
- Pelvis. This is a small cavity in the middle of the kidney where urine collects. Urine from the renal pelvis enters the ureter, and from there it is completely eliminated from the body.
- The fibrous capsule is the membrane that covers the outside of the kidney. Normally, it should be smooth and clearly defined.
- Echotenosis, hierechogenic inclusion, echogenic formation indicates the presence of stones or sand.
- Kidney microcalculosis means that small stones up to 5 mm or sand were found in the kidneys.
Signs of Healthy Kidneys
Signs healthy organs abdominal cavity:
- the shape of the kidneys is bean-shaped, the outlines of the organ are clear, there are no signs of changes in urinary outflow;
- the aortic diameter is normal, there is no aneurysm;
- The abdominal organs are normal, there is no proliferation of tissue and fluid;
- thickness gallbladder normal, ducts are not dilated, no stones;
- the liver is normal, the structure is not changed.
Changes indicating pathologies
The examination may show deviations from the norm; therefore, the conclusion of the kidney ultrasound indicates the following description of the anomalies:
- the size of the organ is increased, urinary outflow is impaired, the ureters are dilated, kidney stones are present;
- the aorta is dilated, there are symptoms of an aneurysm;
- there are signs of inflammation, infection, disease;
- organs are displaced, tissue is growing, or there is fluid in the abdominal cavity;
- the walls of the gallbladder are thickened, the ducts are dilated, stones are present;
- there are signs of heatomegaly, the structure of the organ is changed.
What do the colors mean on a kidney ultrasound?
In addition to blood flow, the structure of kidney tissue can also allow it to be visualized in color, an ability called echogenicity.
Echogenicity of tissues and pathological formations on ultrasound:
Characteristics of the pathology
Description of how ultrasound will show pathology in conclusion:
- If the kidney is too mobile or its position is displaced, a diagnosis of nephroptosis is made.
- A wrinkled kidney indicates nephrosclerosis.
- Hyperechoic inclusions on ultrasound (darkening, darkening) look like neoplasms in the form of sand or stones. In this case, microcalculosis is diagnosed.
- Neoplasms in the form of cysts or abscesses are diagnosed with low echogenicity.
- Seals and neoplasms in the form of tumors may indicate oncology or renal hemangioma. This pathology is usually diagnosed even when the tumor is located in the organ bed. Kidney cancer can be more accurately determined with additional cancer tests.
- Structural changes, uneven contours, enlarged kidneys or low mobility - the patient has pyelonephritis.
- Uneven contours, increased echogenicity, decreased blood flow - renal failure is diagnosed.
- The thickness of the parenchyma decreases, there is no visualization of the hydronephrotic sac - characteristic of hydronephrosis.
- If a decrease in the size of the kidneys is visible, a diagnosis of glomerulonephritis or a congenitally hypoplastic kidney is made.
- An increase in size indicates hydronephrosis, tumor processes, blood stagnation.
- An increase in the width of the renal pelvis is inflammation or signs of diseases of the urinary system.
- A spongy kidney indicates deformation of the renal canals - Malpighian pyramids, which are affected by many cysts.
- The horseshoe kidney speaks of congenital anomaly fusion of the two poles of the kidney with each other. In this case, a diagnosis of pyelonephritis, nephrolithiasis, hydronephresis or arterial hypertension is made.
Photo gallery
The photo clearly shows kidney pathologies on ultrasound images.
Video
The video clearly describes kidney anomalies during their development. Provided by the Petr Ivachev channel.