Hypertrophied bertini column. Terms and definitions for computed tomography of the kidneys

Kidney structure

The kidneys are located retroperitoneally in the lumbar region at the level of the last two thoracic vertebrae and the first two lumbar vertebrae. The right kidney is usually 1–2 cm lower than the left.

The parenchyma of the kidney consists of a cortical layer and pyramids. The renal pillars (Bertini columns) between the pyramids are composed of crustal matter. The pyramid and the cortical substance covering it form a renal lobule. At the top of the pyramid, the openings of the papillary tubules open.

The renal sinus contains the pyelocaliceal complex (PLC), blood vessels, nerves, connective tissue, and fat. The small cup sits on top of the pyramid like a breast pump on a nipple. Urine actively flows into small and large cups → renal pelvis → ureter → bladder → urethra.

Click on the pictures to enlarge.

Kidney ultrasound

A 2.5-7.5 MHz convex transducer is used. If a pathology is suspected, the study is carried out with a filled bladder when the urge to urinate appears. After urination, the kidneys are re-examined.

We are interested in the location, size, echogenicity, echo structure of the kidneys, as well as the patency of the urinary tract. How to estimate the size of the kidneys in children and adults, see more details.

Bladder and distal ureter on ultrasound

In the suprapubic position of the patient, we remove the bladder. Assess the filling of the bladder and the distal ureters. Normally, the distal ureter is not visible. A ureter more than 7 mm in diameter is a megaureter.

Drawing. On ultrasound, a dilated distal ureter (1, 2, 3). For ureterocele (3) see more details.

Echogenicity of the kidneys

With the patient in the supine position along the midclavicular and anterior axillary lines, draw the right kidney in the vicinity of the liver, and the left kidney near the spleen. Evaluate the echogenicity of the kidneys. The cortical layer of the kidney is normally iso- or hypoechoic in relation to the liver and hypoechoic in relation to the spleen.

Drawing. The echogenicity of organs is compared on one section. Ultrasound shows a normal kidney adjacent to the liver (1) and spleen (2). In children under 6 months of age, renal parenchyma can normally be hyperechoic compared to the liver (3).

Kidney shape on ultrasound

To see the upper pole of the kidney, ask the patient to take a deep breath. The shape of the kidney is bean-shaped - convex from the lateral side and concave from the medial side. As a variant of the norm, an embryonic lobular kidney, as well as a humpbacked left kidney, is considered.

Drawing. On ultrasound (1) and CT (2, 3), the contour of the kidneys is wavy. In the embryo, the kidney develops from separate lobules, which merge as they grow. The lobular structure of the kidneys is clearly visible in the fetus and newborns, in isolated cases it remains in adults.

Drawing. You can find a humped left kidney - a convex, uneven outer contour due to parenchymal hypertrophy in the middle third of the kidney. It is believed that the "hump" is formed in the fetus under pressure from the lower edge of the spleen.

Drawing. Scanning from the side of the anterior abdominal wall allows you not to miss the isthmus between the kidneys. The isthmus in front of the spine is evidence of renal fusion - a horseshoe-shaped kidney. See Horseshoe Kidney Anatomy Options.

Video. U-shaped kidney on ultrasound

Echostructure of the kidneys

In a normal kidney, the pyramids are hypoechoic, the cortex and Bertini's columns are isoechoic to each other. In the sinus, there is normally an invisible PLC, hyperechoic connective and adipose tissue, hypoechoic vessels and the tops of the pyramids.

When the pyramids, cortical substance, renal columns are distinguished, the echostructure of the kidney parenchyma is not changed. If they are not visible, then the echo structure is changed due to the lack of clear cortical-cerebral differentiation.

Drawing. On ultrasound, a kidney with an unchanged echo structure: a cortical layer and Bertini's columns hypoechoic in relation to the liver, almost anechoic pyramids, hyperechoic sinus.

Drawing... In 37% of healthy newborns in the first day of life, ultrasound diagnoses the symptom of "white pyramids". The precipitation of Tamm-Horsfall protein and uric acid causes reversible tubular obstruction. By 6 weeks of life, it passes without treatment.

Drawing. Ultrasound examination of a healthy kidney: along the base of the pyramids (corticomedullary junction), linear hyperechoic structures with a hypoechoic pathway in the center are determined. These are arcuate arteries, which are mistakenly regarded as nephrocalcinosis or stones.

Video. Arcuate arteries of the kidney on ultrasound

Drawing. On ultrasound, the lower pole of the kidney is separated by a hyperechoic fibrous jumper; the pelvis of the lower segment is 7 mm. This is a variant of the normal structure of the kidney. The kidney can be deformed, so its size and length are slightly less than the opposite. A slight expansion of the pelvis under the lintel remains for life.

Video. On ultrasound, a fibrous bridge in the kidney (structure variant)

Sometimes Bertini's column cuts into the central part of the kidney, dividing it fully or incompletely into two parts. Such a parenchymal jumper is the parenchyma of the pole of one of the embryonic lobules, which merge to form a kidney; consists of bark, pyramids, Bertini columns - all elements without signs of hypertrophy or dysplasia. The term Bertini's column hypertrophy does not reflect the morphology of the structure, or rather, consider this formation as a parenchymal bridge.

Drawing. On ultrasound, a rounded formation divides the renal sinus into two segments with a common pelvis; interlobar arteries bend around the formation; the echogenicity and intensity of the vascular pattern inside is close to the cortical zone. Conclusion: Hypertrophy of the Bertini column or incomplete parenchymal jumper. This is a variant of the normal structure of the kidney. The term "incomplete doubling of the PMC" is incorrect, because incomplete parenchymal jumper is not a sign of duplication of the PLC.

Drawing. On ultrasound, the renal sinus is separated by a complete parenchymal jumper (1, 2). In such cases, excretory urography will help to distinguish the duplication of the kidney from the hypertrophy of the Bertini column. The duplicated kidney is covered with a common fibrous capsule. Full doubling assumes the presence of two pelvis, two ureters and two vascular bundles. The half-doubled kidney (3) feeds on one vascular bundle, the ureter can be doubled at the top and flow into the bladder with one or two mouths. Doubling of the PLC and ureters is a risk factor for the development of pathology (pyelonephritis, hydronephrosis, etc.).

Drawing. On ultrasound, the renal sinus is wide, with a heterogeneous echo structure (1, 2). Against the background of hyperechoic fat, there is a hypoechoic focus of a round shape (2); with CDC, the interlobar vessels pass through the hypoechoic zone without displacement (3) - this is hypoechoic fat. In obesity, sinus lipomatosis can be mistaken for parenchymal atrophy.

The ureter, small and large calyces are normally not visible on ultrasound. There are three types of pelvis location: intra-, extrarenal and mixed (partly inside the kidney, partly outside it). With the intrarenal structure, the lumen of the pelvis at an early age is up to 3 mm, at 4-5 years old - up to 5 mm, in puberty and in adults - up to 7 mm. With extrarenal and mixed type of structure - 6, 10 and 14 mm, respectively. With an overflowing bladder, the pelvis can increase up 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, 2) and extrarenal (3) location.

Drawing. In children under 1 year of age, ultrasound of the kidney sinus is poorly determined; anechoic pyramids can be mistaken for an enlarged PLC (1). On ultrasound at the hilum of the kidney, the linear hypoechoic structure looks like an enlarged pelvis (2); at CDC it is seen that these are vessels (3).

Abnormalities of the location of the kidneys on ultrasound

Anomalies in the location of the kidneys occur when there is a violation of the movement of the primary kidney from the pelvis to the lumbar region. Almost always, the shape of the kidney is changed, and the gate is open forward.

In thoracic dystopia, the kidney is usually part of a diaphragmatic hernia. With lumbar dystopia, the pelvis is at the L4 level, with the iliac - L5-S1. The pelvic kidney is located behind or just above the bladder. In cross-dystopia, the ureter flows into the bladder in its usual place, and the kidney is displaced contralaterally.

Drawing. Dystopia of the kidneys in relation to the skeleton: thoracic right (1), bilateral lumbar (2), pelvic left (3), lumbar right and pelvic left (4), lumbar doubled left kidney (5), cross (6).

Drawing. Dystopia of the kidneys in relation to each other and their fusion among themselves: fusion of the upper ends (1), the lower ends and doubling of the left kidney (2), the middle parts of the pelvic-dystopic kidneys (3), the lateral parts of the pelvic-dystopic kidneys (4), different ends (5), at an angle (6).

Drawing. On ultrasound, the renal bed on the left is empty (1). Both kidneys are located on the right; they grow together at the poles (2, 3). Conclusion: Anomaly of the kidney relationship - I-shaped doubled right kidney.

Drawing. Ultrasound in the small pelvis (bladder - acoustic window) identifies the kidneys connected by a narrow isthmus (1, 3); differentiation of the parenchyma is preserved, the blood flow is traced to the capsule (2, 3). Conclusion: Anomaly of the kidney relationship - fusion of the lower poles of the pelvic-dystopic kidneys.

Kidney mobility on ultrasound

We mark on the skin the level of the upper pole of the kidney in the position of the patient lying on his stomach and standing. Ask the patient to jump before taking another measurement.

Normally, on inhalation, the kidneys fall by 2-3 cm.In adults, one can speak of abnormal mobility of the kidney if on ultrasound in a standing position the kidney shifts by 5 cm.In children, a displacement of 1.8-3% of height indicates excessive mobility, displacement\u003e 3% is an indirect sign of nephroptosis. Nephroptosis is established by X-ray - this is the movement of the kidney more than 2 times the height of the vertebral body.

How to distinguish nephroptosis from dystopia on ultrasound? Normally, the PA departs from the aorta immediately below the SMA, with lumbar dystopia - near the aortic bifurcation, with pelvic dystopia - from the iliac artery.

Drawing. In case of pelvic dystopia on intravenous urography in the supine position, the ureter is short, the kidney is in the pelvis (1, 2). With nephroptosis on intravenous urography in the supine position, the kidney is determined in a typical place (3), in the standing position the kidney is significantly lowered (4).

Take care of yourself, Your Diagnostician!

Video. Kidney ultrasound lectures by Vladimir Izranov

The term "nephrosclerosis" refers to the replacement of the renal parenchyma by connective tissue. Renal nephrosclerosis can occur due to various diseases of the kidneys and renal vessels.

Causes of the disease

According to the mechanism of development, the following types of nephrosclerosis are distinguished:

1. primary (caused by impaired blood supply to the renal tissue in hypertension, atherosclerosis, and other diseases);
2. secondary (developing as a result of various kidney diseases, for example, with nephritis).

Primary nephrosclerosis can occur when the renal arteries are narrowed due to atherosclerotic lesions, thrombosis, or thromboembolism. Ischemia leads to the formation of heart attacks and scars in the kidneys. A similar picture is observed with hypertension, as a result of hypertensive arteriolosclerosis, with stagnation of venous blood in the kidneys, due to age-related changes in the vessels.

A classic example of primary nephrosclerosis is the primary contracted kidney, which develops in the late stages of hypertension. Due to circulatory failure and hypoxia, atrophic and dystrophic changes occur in the renal tissue with a gradual proliferation of connective tissue.

Thus, primary nephrosclerosis can be divided into the following forms:

• atherosclerotic,
• involutive,
• hypertensive nephrosclerosis,
• other forms.

Secondary nephrosclerosis, or secondary wrinkled kidney, occurs as a result of inflammatory and dystrophic processes that develop directly in the kidneys:

• chronic glomerulonephritis,
• pyelonephritis,
• kidney stone disease,
• kidney tuberculosis,
• syphilis with kidney tissue damage,
• systemic lupus erythematosus (lupus nephritis),
• amyloidosis of the kidneys,
• diabetes mellitus (diabetic nephritis),
• kidney injury, including repeated surgery,
• exposure to ionizing radiation,
• severe forms of nephropathy in pregnant women.

In addition, a peculiar form of nephrosclerosis with dilatation and cystic transformation of the kidney tubules develops in gout and oxalaturia as a result of crystalluric interstitial nephritis, as well as in hyperparathyriosis, accompanied by increased calciuria. Radiation nephrosclerosis is usually detected many months or even years after radiation exposure. Its severity depends on the type of radiation and dose.

Shriveled kidney

Pathological anatomy

In the pathogenesis of nephrosclerosis, two phases are distinguished:

1. In the first phase, a picture is observed in the kidneys, due to a specific disease that caused the sclerotic process;
2. In the second phase, the features of nephrosclerosis inherent in the disease that caused it are lost.

During the second phase, the sclerotic process invades all new areas of the kidney tissue until the entire kidney is largely affected. With an expanded picture of the disease, the kidneys are compacted, have an uneven surface. With arterial hypertension and glomerulonephritis, the surface of the kidney is fine-grained, and with atherosclerosis it is large-nodular, has cicatricial retractions of an irregular stellate shape. With pyelonephritis, nephrosclerosis affects the kidneys asymmetrically.

The morphology of the renal tissue reflects the features of the course of the sclerotic process, as well as the rate of increase in severe changes. Depending on the course, the following forms of nephrosclerosis are distinguished:

• benign,
• malignant.

Benign nephrosclerosis is more common, characterized by arteriolosclerosis and atrophy of certain groups of nephrons with hyalinosis of the glomeruli. In this case, the connective tissue grows in the interstitium (interstitial space) and in the place of atrophied areas. In the malignant form, arterioles and capillary glomeruli undergo fibrinoid necrosis, stromal edema, hemorrhages and pronounced dystrophic changes in the tubules are observed. As a result, widespread sclerosis occurs in the kidneys. This form of nephrosclerosis is characteristic of malignant arterial hypertension, eclampsia and some other diseases.

Symptoms and diagnosis of nephrosclerosis

The outcome of a long course of hypertension, as a rule, is nephrosclerosis: its symptoms usually appear in the later stages of the disease. At the early stage of nephrosclerosis, symptoms are mild. In laboratory research, the following changes can be detected:

• polyuria,
• nocturia,
• the appearance of protein in the urine,
• microhematuria,
• decreased urine density.

As a result of a decrease in the osmolarity of urine, edema occurs, which first appears on the face, and in later stages - throughout the body. In addition, in most cases, arterial hypertension develops due to renal ischemia. It is malignant and difficult to treat. Renal arterial hypertension often leads to the following complications:

• overload of the left ventricle of the heart with coronary insufficiency,
• strokes,
• edema of the papilla of the optic nerve and its atrophy up to complete blindness,
• retinal disinsertion.

Ultrasound, X-ray and radionuclide studies play an important role in the diagnosis. With ultrasound of the kidneys, it is possible to detect a change in their size, determine the thickness of the parenchyma and the degree of atrophy of the cortex. Urography allows you to determine a decrease in the volume of the affected kidney and cortical layer, sometimes calcifications are visible. On the angiogram, narrowing and deformation of small arteries, and an uneven surface of the kidneys are observed. Radionuclide renography reveals a slowdown in the accumulation and excretion of the radiopharmaceutical from the kidneys. During scintigraphy, radionuclides are unevenly distributed in the kidney tissue; in severe cases, the image of the kidney may be absent.

Advice: if you find edema of unknown origin, high blood pressure with headache and visual impairment, you should immediately seek medical help. Timely started treatment will avoid such formidable complications as stroke, blindness, etc.

The end result of nephrosclerosis is severe chronic renal failure and intoxication of the body with nitrogenous wastes.

General principles of treatment of renal nephrosclerosis

When diagnosed with renal nephrosclerosis, treatment depends on the manifestations of the disease. If nephrosclerosis is not accompanied by obvious signs of renal failure, but is manifested by an unstable increase in blood pressure, then the treatment consists in limiting the intake of sodium chloride and liquid and the use of antihypertensive drugs. In addition, diuretics, anabolic drugs, enterosorbents, vitamins are used.

With severe renal failure, antihypertensive drugs should be prescribed with great caution, since a sharp decrease in blood pressure can lead to impaired renal blood flow and deterioration of organ function.

Important: with azotemia, a protein-restricted diet should be followed, this will reduce the formation of nitrogenous toxins in the body.

In case of malignant hypertension with rapidly developing nephrosclerosis and progressive renal failure, renal artery embolization or nephrectomy is performed, followed by transfer to hemodialysis. Kidney transplantation is also possible.

A 50-year-old man complains of losing weight for 2 months, weakness, apathy, bone pain. Moderate pain in the lumbar region is more related to movement. A month ago, an increase in t-ry within a week is associated with ARVI, an inexplicable increase in pressure, mainly diastolic up to 100-110. On ultrasound in the abdominal cavity, I found only a change in the left kidney in the sinus at the border of the upper and middle third, an isoechoic formation with a fuzzy capsule with arterial vascularization according to pyrephyria is determined, in the parenchyma of the middle third there is a small anechoic cyst with the presence of a hyperechoic intermittent capsule. There was no hematuria, the tapping symptom was negative. In conclusion, he wrote the formation of the sinus of the left kidney to differentiate RCC, MTS, angiolipoma or pseudotumor (hypertrophied Bertini's column) parenchymal cyst according to Bosnyak 2 Recommended URO CT. What is your opinion?

Today I reviewed the patient and used a different sensor and there was more time. I brought out transverse scans, but all the same I think this is Bertini's column. On the second scan, next to the cyst. I post scans.

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The pyramids of the kidneys are defined as the specific areas through which urine enters the calyx-pelvic system after filtration of fluid from the bloodstream through the tubular systems. Already from the chls, urine moves along the ureter and enters the bladder. Violations of the pyramids can be observed in one or both kidneys, which leads to dysfunction of the organ and requires mandatory treatment. The identification of pathological changes is carried out by means of ultrasound and only after examination and diagnosis, the doctor prescribes the necessary therapy.

What does the hyperechogenicity of pyramids mean?

Pyramids of the kidneys are defined areas through which urine enters the calyx-pelvic system after filtration of fluid from the bloodstream.

The normal healthy state of the kidneys means the correct shape, the uniformity of the structure, the symmetrical arrangement, and at the same time, the ultrasound waves on the echogram - a study carried out when a disease is suspected, are not reflected. Pathologies, on the other hand, change the structure, appearance of the kidneys and have special characteristics that indicate the severity of the disease and the state of the inclusions.

For example, organs can be asymmetrically enlarged / reduced, have internal degenerative changes in the parenchymal tissue - all leads to poor penetration of the ultrasound wave. In addition, echogenicity is impaired due to the presence of stones and sand in the kidney.

Important! Echogenicity is the ability of a wave to reflect sound from a solid or liquid substance. All organs are echogenic, which allows an ultrasound scan. Hyperechogenicity is a reflection of increased strength, revealing inclusions in organs. Based on the readings of the monitor, the specialist detects the presence of an acoustic shadow, which is the determining factor in the density of inclusion. Thus, if the kidneys and pyramids are healthy, the study will not show any wave deviations.

Symptoms of hyperechogenicity

Syndrome of hyperechoic kidney pyramids causes pain in the lower back of a cutting, stabbing nature

Syndrome of hyperechoic renal pyramids has a number of symptoms:

• Body temperature changes;
• Pain in the lower back of a cutting, stabbing character;
• Change in color, odor of urine, sometimes blood droplets are observed;
• Stool disorder;
• Nausea, vomiting.

The syndrome and symptoms indicate an overt kidney disease that needs to be treated. Isolation of pyramids can be caused by various organ diseases: nephritis, nephrosis, neoplasms and tumors. Additional diagnostics, doctor's examination and laboratory tests are required to establish the underlying disease. After that, the specialist prescribes measures of therapeutic treatment.

Types of hyperechoic inclusions

All formations are divided into three types, based on what picture is visible on ultrasound

All formations are divided into three types, based on what picture is visible on ultrasound:

A large inclusion, which has an acoustic shadow, most often indicates the presence of stones, focal inflammation, disorders of the lymphatic system;

A large formation without a shadow can be triggered by cysts, fatty layers in the sinuses of the kidneys, tumors of a different nature or small calculi;

Small inclusions without a shadow are microcalcivicates, psammary bodies.

Possible diseases depending on the size of the inclusions:

Urolithiasis or inflammation - manifested by large echogenic inclusions.

Single inclusions without a shadow signal:

• hematomas;
• sclerotic vascular changes;
• sand and small-format calculi;
• scarring of organ tissues, for example, parenchymal tissues, where scarring has occurred due to untreated diseases;
• fatty seals in the sinuses of the kidneys;
• cystosis, tumors, neoplasms.

Important! If the monitor of the device shows obvious sparkles without a shadow, then in the kidneys there may be an accumulation of compounds (psammomny) of a protein-fatty nature, framed by calcium salts or calcifications. It is not recommended to skip this symptom, as this may be the beginning of the development of malignant tumors. In particular, oncological formations include calcifications in 30%, psammon bodies in 50%.

The inclusion of an echo complex of the kidneys on an ultrasound scan is a study that allows one to identify abnormal developments in all parts of the organ, the dynamics of diseases and parenchymal changes. Depending on the echogenic parameters, the characteristics of the disease are determined, therapeutic and other treatment is selected.

As for the symptomatology, even knowing what it is about the pyramids in the kidneys, what pathologies are indicated by changes in structure and echogenicity, the lack of signs of the disease often does not cause concern. Patients resign themselves to pain and delay the visit to the doctor. It is categorically not recommended to do this: if the disease has touched the pyramid, it means that the pathological changes have gone far enough and can turn into not only purulent inflammatory processes, but also chronic diseases, the treatment of which will take a lot of time and money.

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The structure and purpose of the parenchyma

Under the capsule are several layers of dense parenchymal substance, differing both in color and consistency - in accordance with the presence of structures in them that allow performing the tasks facing the organ.

In addition to its most famous purpose - to be part of the excretory (excretory) system, the kidney also performs the functions of an organ:

• endocrine (intrasecretory);
• osmo- and ion-regulating;
• participating in the body both in the general metabolism (metabolism) and in hematopoiesis - in particular.

This means that the kidney not only filters the blood, but also regulates its salt composition, maintains the water content that is optimal for the body's needs, affects the level of blood pressure, and also produces erythropoietin (a biologically active substance that regulates the rate of erythrocyte formation) ...

Cortical and medullary layers

According to the generally accepted position, the two layers of the kidney are usually called:

• cortical;
• brain.

The layer that lies directly under the dense elastic capsule, the outermost in relation to the center of the organ, the densest and most light-colored, is called cortical, while the one located under it, darker and close to the center, is the cerebral layer.

A fresh longitudinal section reveals even to the naked eye the heterogeneity of the structure of the renal tissues: it shows radial striation - structures of the medulla, which are pressed into the cortical substance with semicircular tongues, as well as the red dots of the renal corpuscles-nephrons.

With a purely external monolithicity, the kidney is characterized by lobulation, due to the existence of pyramids, delimited from each other by natural structures - renal columns formed by the cortical substance dividing the brain into lobes.

Glomeruli and urine formation

To be able to purify (filter) blood in the kidney, there are zones of direct natural contact of vascular formations with tubular (hollow) structures, the structure of which makes it possible to use the laws of osmosis and hydrodynamic (arising from fluid flow) pressure. These are nephrons, the arterial system of which forms several capillary networks.

The first is a capillary glomerulus completely immersed in a cup-shaped depression in the center of the flask-shaped expanded primary element of the nephron - the Shumlyansky-Bowman capsule.

The outer surface of the capillaries, consisting of a single layer of endothelial cells, is almost entirely covered with cytopodia intimately tightly adjacent to it. These are numerous leg-shaped processes that originate from the centrally passing cytotrabekula beam, which in turn is a process of a podocyte cell.

They arise as a result of the entry of the "legs" of some podocytes into the gaps between the same processes of other, neighboring cells with the formation of a structure resembling a "lightning" lock.

The narrowness of the filtration slits (or slit diaphragms), due to the degree of contraction of the "legs" of podocytes, serves as a purely mechanical obstacle for large molecules, preventing them from leaving the capillary bed.

The second miraculous mechanism that ensures the fineness of filtration is the presence on the surface of slit diaphragms of proteins that have an electric charge that is the same as the charge of molecules approaching them in the filtered blood. This electrical "curtain" also prevents unwanted components from entering the primary urine.

The mechanism of formation of secondary urine in other parts of the renal tubule is due to the presence of osmotic pressure directed from the capillaries into the lumen of the tubule, braided by these capillaries until their walls "stick" to each other.

Parenchyma thickness at different ages

In connection with the onset of age-related changes, tissue arthrophy occurs with a thinning of both the cortical and medullary layers. If at a young age the thickness of the parenchyma is from 1.5 to 2.5 cm, then upon reaching 60 or more years it becomes thinner to 1.1 cm, leading to a decrease in the size of the kidney (its shrinkage, usually bilateral).

Atrophic processes in the kidneys are associated both with the conduct of a certain lifestyle, and with the progression of diseases acquired during life.

The conditions causing a decrease in the volume and mass of the renal tissue are caused by both general vascular diseases of the sclerosing type, and the loss of the ability by the renal structures to carry out their functions due to:

• voluntary chronic intoxication;
• sedentary lifestyle;
• the nature of the activity associated with stress and occupational hazards;
• living in a certain climate.

Column Bertini

Also referred to as bertinium columns, or renal pillars, or Bertin's pillars, these beam-like bands of connective tissue that run between the pyramids of the kidney from the cortex to the medulla divide the organ into lobes in the most natural way.

Because inside each of them there are blood vessels that provide metabolism in the organ - the renal artery and vein, at this level of their branching they are called interlobar (and at the next - lobular).

Thus, the presence of Bertin's pillars, which differ in a longitudinal section from the pyramids in a completely different structure (with the presence of sections of tubules passing in different directions), allows communication between all zones and formations of the renal parenchyma.

Despite the possibility of the existence of a fully formed pyramid inside the especially powerful Bertin's pillar, the same intensity of the vascular pattern in it and in the cortical layer of the parenchyma testifies to their common origin and purpose.

Parenchymal jumper

The kidney is an organ that can take any shape: from the classic bean-shaped to the horseshoe-shaped or even more unusual.

Sometimes ultrasound of an organ reveals the presence of a parenchymal bridge in it - a connective tissue retraction, which, starting on its dorsal (posterior) surface, reaches the level of the median renal complex, as if dividing the kidney across into two more or less equal "semi-fasolines". This phenomenon is explained by too strong wedging of Bertin's pillars into the kidney cavity.

For all the seeming unnaturalness of such an organ's appearance, with the absence of its vascular and filtering structures, this structure is considered a variant of the norm (pseudopathology) and is not an indication for surgical treatment, as well as the presence of a parenchymal constriction dividing the renal sinus into two seemingly separate parts, but without complete doubling of the pelvis.

The ability to regenerate

Regeneration of the renal parenchyma is not only possible, but also safely carried out by the organ under certain conditions, which has been proven by many years of observation of patients who have undergone glomerulonephritis - an infectious-allergic-toxic kidney disease with massive damage to the renal corpuscles (nephrons).

Studies have shown that the restoration of organ function occurs not through the creation of new ones, but through the mobilization of existing nephrons, which were previously in a conserved state. Their blood supply remained sufficient solely to maintain minimal vital activity in them.

But the activation of neurohumoral regulation after the acute inflammatory process subsided led to the restoration of microcirculation in areas where the renal tissue did not undergo diffuse sclerosis.

These observations allow us to conclude that the key point for the possibility of regeneration of the renal parenchyma is the ability to restore blood supply in areas where it has significantly decreased for any reason.

Diffuse changes and echogenicity

In addition to glomerulonephritis, there are other diseases that can lead to the appearance of focal atrophy of the renal tissue, which has varying degrees of extent, called the medical term: diffuse changes in the structure of the kidneys.

These are all diseases and conditions leading to vascular hardening.

The list can begin with infectious processes in the body (flu, streptococcal infection) and chronic (habitual household) intoxication: alcohol intake, smoking.

It ends with industrial and service-related hazards (in the form of work in an electrochemical, galvanic workshop, activities with regular contact with highly toxic compounds of lead, mercury, as well as those associated with exposure to high-frequency electromagnetic and ionizing radiation).

The concept of echogenicity implies the heterogeneity of the structure of an organ with varying degrees of permeability of its individual zones for ultrasound examination (ultrasound).

Just as the density of various tissues is different for X-ray "transmission", both hollow formations and areas with a high tissue density are also found on the path of the ultrasound beam, depending on which the ultrasound picture will be very diverse, giving an idea of \u200b\u200bthe internal structure organ.

As a result, the ultrasound method is a truly unique and valuable diagnostic study that cannot be replaced by any other one that allows you to give a complete picture of the structure and function of the kidneys without resorting to autopsy or other traumatic actions in relation to the patient.

Also, an outstanding ability to recover in case of damage, it is possible to largely regulate the life of an organ (both by saving it by the owner of the kidneys, and by providing medical care in cases requiring intervention).

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Syndrome of hyperechoic renal pyramids

If it is long, then chronic renal failure, if acute, then acute renal failure. Poisoning can be the cause of both. The kidneys play an important role in the human body and overall health depends on their normal functionality. Therefore, when the first signs of malaise appear, it is recommended to immediately provide the necessary assistance to the kidneys.

Common Symptoms That Cause Kidney Problems

When these symptoms appear, it is important to immediately contact your attending physician, who will prescribe an immediate examination and the necessary tests. Also, these symptoms may indicate that the patient has one kidney larger than the other, so it is necessary to undergo additional examination, including renal clearance. In the event that, after hypothermia, the kidneys began to hurt in a person, only one conclusion can be drawn - this means that the development of the inflammatory process began earlier.

Symptoms associated with kidney disease

A person can get closed kidney injuries in car accidents, when falling from a height, and even while playing sports. Each of these types of diseases has its own dangers, so in no case should you experiment on yourself and self-medicate. Often, patients who actually have a kidney carbuncle end up in the hospital under completely different diagnoses.

Types of hyperechoic inclusions and diagnostics

With this disease, pus is also released, so it is very dangerous and requires immediate hospitalization of the patient in a medical institution. It has been proven that dietary nutrition has a very beneficial effect on many kidney diseases and allows them to work in a sparing mode.

The kidneys are a paired organ and in the human body they perform several functions at the same time. Therefore, during a diagnostic ultrasound examination, a mandatory examination of both kidneys is carried out. The dysfunction can start on one side and affect the other. Hyperechoic inclusions in the kidneys can be observed in one or two. The location of the inclusions is very diverse and depends on the predisposing unfavorable factors.

Kidney Disease Website

Pathological processes of various etiologies change the structure and appearance of the kidneys, depending on the severity of the disease and the state of the inclusions. Hyperechogenicity means super strong reflection, indicating the presence of any inclusions in the kidney. There are several types of echogenic inclusions, which determine the pathological state of the kidneys. Hyperechoic inclusions are divided into two large groups: stones (sand) and neoplasms.

Large inclusions in the kidneys. This can also be confirmed by the presence of calcifications and psammotic bodies in the tumor, as well as sclerosed areas. During the examination, several different types of echogenic inclusions can be found. Disruption of kidney function is always accompanied by weakness and fatigue. This condition is inherent in the acute development of diseases or the phase of exacerbation of chronic pathological processes in the kidneys.

Therapeutic measures and prevention

It is necessary to assess the state of the renal parenchyma against the background of prominent pyramids. Depending on the neglect of the condition and the type of pathological process, treatment can be therapeutic or surgical.

Pyelonephritis is an inflammatory process that occurs only in the calyx-pelvic system of the kidney, accompanied by pronounced laboratory changes. Fig. 1 Visualization of the right kidney. The sensor is located in the right posterior axillary line.

Necessary treatment

As with a complete examination of any other organs, it is necessary to examine the kidney in a second projection to examine its cross-section. The sensor can be installed directly under the costal arch or in the area of \u200b\u200bthe last intercostal space.

Clinical manifestations

The left kidney is also located in a kind of triangle, the sides of which are the spine, muscles and spleen. The echographic characteristics of the renal capsule and parenchyma of the normal kidney are generally accepted.

Partial or complete rupture of the collecting system image at the same site indicates a doubling of the kidney with separate ureters and blood supply for each half.

Kidney dystopia is an abnormality in the development of the kidney, in which the kidney does not rise to its normal level during embryogenesis. In this case, variants of heterolateral dystopia with and without renal fusion are possible. With echographic detection of an abnormally located kidney, difficulties usually arise in the differential diagnosis of nephroptosis and dystopia. It should be remembered that the kidney with nephroptosis has a normal length of the ureter and a vascular pedicle located at the usual level (level L1-L2 of the lumbar vertebrae).

As for the increase in the echogenicity of the parenchyma and the prominent pyramids, here the reasons for this condition may be different. In newborns, the structure and condition of the pyramids themselves and the fluids released through them are assessed. The base of the triangle is the border between the cortex and the pyramid along the periphery of the pyramid cut. The syndrome itself is not life-threatening and is a symptom of a disease that is established after a complete comprehensive examination.

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Concepts - hyperechoicity and acoustic shadow?

Echogenicity is the ability of bodies of liquid and solid consistency to beat off ultrasonic waves. All organs located inside a person are echogenic, this is what allows ultrasound examination. Ultrasound helps to study the activity of the kidneys, determine their integrity and confirm or exclude the presence of malignant or benign neoplasms. A healthy person has a rounded organ with a symmetrical location and an inability to reflect sound waves. In cases of pathologies, the size of the kidneys changes, the location becomes asymmetrical and inclusions appear that can beat off sound waves.

On ultrasound, hyperechoic inclusions look like white spots.

Hyper refers to the increased ability of echogenic tissues to reflect ultrasonic waves. During an ultrasound scan, a specialist sees white spots on the screen and determines whether they have an acoustic shadow, more precisely, a cluster of ultrasonic waves that did not pass through it. Waves have a much higher density than air; therefore, they cannot pass exclusively through a dense object. Hyperechogenicity is not a separate disease, but a symptom indicating the appearance of various kinds of pathologies inside the kidneys.

Kidneys and paranephria are normal

The kidneys are located on either side of the spinal column. Their upper third is covered with ribs that run over them anteriorly, dropping downward. When viewed from the back and from the side, the longitudinal axes of the kidneys form an acute angle with the spine. The transverse axes of the kidneys form an angle of approximately 45 ° with the sagittal plane. The kidneys are located retroperitoneally. The right kidney is at the level of Th-12-L-4, the left kidney is located higher - at the level of the Th-11-L3 vertebra. However, it is rather inconvenient to determine the position of the kidney relative to the vertebrae, therefore, in echographic practice, a hypoechoic acoustic "shadow" from the twelfth rib, the dome of the diaphragm (or diaphragmatic contour of the liver), the gate of the spleen, the contralateral kidney are used as a reference point for determining the position of the kidney. "from the twelfth rib crosses (with longitudinal scanning from the back parallel to the long axis of the kidney) the right kidney at the level of the borders of the upper and middle third, the left kidney at the level of the hilum of the kidney. Usually the kidneys are clearly visible when the patient is lying on his side. The longitudinal section of the kidney is visible when the sensor is placed on the extension of the intercostal line from the side.During a deep inhalation, the kidneys move down from under the acoustic shadow of the ribs and are visible in their longitudinal section.

Fig. 1 Visualization of the right kidney. The sensor is located in the right posterior axillary line. N - kidney, L - liver.

The upper pole of the right kidney is located at or slightly below the upper diaphragmatic contour of the right lobe of the liver. The superior pole of the left kidney is located at the level of the hilum of the spleen. The distances from the upper pole of the right kidney to the contour of the diaphragm and from the upper pole of the left kidney to the hilum of the spleen depend on the degree of development of the perirenal tissue of the subject.

To obtain a longitudinal sonongram of the right kidney in the supine position of the patient, use the serodic shown in Fig. 2.

Fig. 2. To obtain an image in the lateral plane, the transducer is shifted laterally from the paramedial position. This plane is used to assess the pleural angle distal to the diaphragm (D) and to obtain a longitudinal section of the kidney (K) posterior to the liver (L).

As with a complete examination of any other organs, it is necessary to examine the kidney in a second projection to examine its cross-section. The sensor can be installed directly under the costal arch or in the area of \u200b\u200bthe last intercostal space. It should be remembered that the lower parts of the kidney are located closer to the sensor, the upper parts are removed from it, i.e. the longitudinal axis runs from top to bottom and from the central axis of the body in the lateral direction.

Fig. 3.a-c Visualization of the right kidney in lateral cross section

A transverse sonography of the right kidney can be performed with the patient supine.

Fig. 4. When evaluating the longitudinal section of the kidney, the transducer is rotated laterally in the mid-abdomen and moved towards the midline. The kidney will be visualized in cross section, posterior to the liver (L). At the level of the renal hilum in the anteroposterior direction, the vascular pedicle of the kidney, including the renal vein (Vr) and the renal artery (Ar), will be visualized, and the ureter can also be determined. In patients with poorly expressed subcutaneous adipose tissue, the place where the renal vein flows into the vena cava (Vc), the place where the renal artery leaves the aorta (Ao) and the gallbladder (Gb) near the lower edge of the liver can be visualized in one image.

Visualization of the left kidney body is similar to visualization of the right kidney.

The left kidney is also located in a kind of triangle, the sides of which are the spine, muscles and spleen. The spleen covers almost half of the kidney. The lower half of the kidney is laterally bordered by the descending colon and the left bend of the colon. The colon bends around the kidney in front. Its upper pole is covered in front by the stomach. Thus, access to the left kidney is optimal from the back and from the side through the intercostal space using the spleen as an ultrasound window. Nevertheless, the quality of visualization of the left kidney is almost always much worse than the right one, especially if it is accompanied by the imposition of intestinal gases.

Fig. 5 Visualization of the left kidney. N - kidney, Mi - spleen, Мр - psoas muscle.

Normal kidney sizes:

Kidney length: 10-12 cm Kidney width: 4-6 cm Respiratory mobility: 3-7 cm Parenchyma thickness: 1.3-2.5 cm

The cut shape of a normal kidney is bean-shaped or oval in all projections. The contour of the kidney is usually even, and in the presence of preserved fetal lobulation of the kidney, it is wavy (this is a variant of the normal structure of the kidney). Echographic characteristics of the renal capsule and parenchyma of the normal kidney are generally accepted. On the periphery of the ultrasound cut of the kidney, a fibrous capsule is determined in the form of a hyperechoic smooth, continuous structure with a thickness of 2-3 mm, then a layer of parenchyma is determined.

Normal renal parenchyma has slightly reduced or similar echogenicity compared to spleen or liver parenchyma. The thickness of the parenchyma should be at least 1.3 cm.The ratio of the thickness of the parenchyma to the width of the renal sinus (\u003d PS index) decreases with age:

PS index (depending on age):

< 30 лет: 1,6: 1

< 60 лет: 1,2-1,6: 1

\u003e 60 years old: 1.1: 1

The hilum of the kidney is determined echographically in the form of a "rupture" in the medial contour of the renal parenchyma, while scanning from the side of the anterior abdominal wall at the top of the scan visualizes the anechoic tubular structure located anteriorly - the renal vein, below - the hypoechoic renal artery located posteriorly. Because of their small size, the ureter and renal artery are often difficult to identify.

The parenchyma is heterogeneous and consists of two layers: the cortical substance and the medullary substance (or the substance of the kidney pyramids). The morphological substrate of the renal cortex (kidney cortex) is mainly the glomerular apparatus, convoluted tubules, interstitial tissue containing blood, lymphatic vessels, and nerves. The cortical substance of the kidney is located on the periphery of the ultrasonic cut of the kidney with a thickness of 5-7 mm, and also forms invaginations in the form of columns (columnae Bertini) between the pyramids. The echogenicity of the renal cortex is usually slightly lower or comparable to the echogenicity of the parenchyma of the normal liver.

Medullary substance contains Henle loops, collecting ducts, Bellini ducts, interstitial tissue. In a standard longitudinal section, the hypoechoic medullary pyramids appear like strands of pearls between the parenchymal cortex and the centrally located echogenic collecting system. They should not be mistaken for tumors or cysts. Often, this difference in echogenicity is the reason for a false-positive diagnosis of hydrocalicosis, when very dark, low echogenicity of the pyramids are mistaken by novice ultrasound diagnostics doctors for dipated cups. Modern histomorphological studies of the renal parenchyma and their comparison with the echographic picture suggest that the pronounced echographic corticomedullary differentiation is due to a significant difference in the number of fatty vacuoles in the epithelium of the tubular structures of the cortex and pyramids. However, it is impossible to explain the different echogenicity of the cortex and pyramids only by the different content of fatty vacuoles in the epithelium of the tubular structures, because It is known that the echogenicity of the pyramids of the kidney at a high level of urine output is significantly lower than the echogenicity of the pyramids of the same kidney under normal conditions, the number of fatty vacuoles does not change depending on the level of urine output. Also, the low echogenicity of the pyramids cannot be explained by the presence of fluid in the tubular structures, because the resolution of the ultrasound apparatus under any conditions does not allow differentiating the lumen of the tubule and the fluid in it. It can be assumed that the low echogenicity of the medullary substance is associated with: 1) a high content of glycosaminoglycans in the interstitial tissue, where most of the functional processes occur that provide ion exchange, reabsorption of water and electrolytes, and urine transport; glycosaminoglycans are able to "bind" the liquid, according to the authors of the hypothesis, "swelling very quickly and from thumping; 2) the presence of smooth muscle fibers in the interstitial tissue surrounding the excretory ducts of the renal papilla.

Often, Bertin's column extends far enough beyond the inner contour of the parenchyma into the central part of the kidney - into the renal sinus, dividing the kidney more or less completely into two parts. The resulting parenchymal "jumper", the so-called. the hypertrophied column of Bertin is a non-absorbed parenchyma of the pole of one of the kidney lobules, which merge during ontogenesis to form an adult kidney. The pyramids of the kidney are defined as structures of a triangular shape with reduced echogenicity compared to the cortex. In this case, the apex of the pyramid (papilla of the pyramid) is facing the renal sinus - in the central part of the cut of the kidney, and the base of the pyramid is adjacent to the parenchymal cortex located along the periphery of the cut. The pyramids of the kidney are 8-12 mm thick (the thickness of the pyramids is defined as the height of the triangular structure, the apex of which is facing the renal sinus), although the normal size of the pyramids largely depends on the level of urine output. Normally, echographic differentiation of the cortex and pyramids is expressed: the echogenicity of the cortical substance is much higher than the echogenicity of the pyramids of the kidney.

Norm options

The normal form of the kidney may have some features that reflect its embryonic development. Hyperplastic Bertini columns can protrude from the parenchyma into the pelvis and do not differ in echogenicity from the rest of the renal parenchyma.

Isoechoic parenchymal bridges can completely separate the collecting system. Partial or complete rupture of the collecting system image at the same site indicates a doubling of the kidney with separate ureters and blood supply for each half. Indeed, difficulties usually arise in the diagnosis of doubling of the pelvic cup system, which is a very common cause of false (false positive and false negative) conclusions. Sometimes the presence of a parenchymal "jumper" - the so-called hypertrophied Bertin's column dividing the renal sinus, is the reason for the echographic diagnosis of incomplete doubling of the pyelocaliceal system. Indeed, cases with complete division of the renal sinus by the parenchymal bridge are accompanied by doubling in more than 50% of cases. pelvis and calyces, however, the most common incomplete ("shallow") bridges are not an ultrasound sign of doubling of the pelvic-pelvic system, although they can give a displacement of the calyx group detected by excretory urography. In this case, ultrasound will help exclude the presence of a volumetric process in the renal sinus.

Fig. 8. Echogram of the kidney with a double cup-pelvis system. The kidney is normally formed. Only a significant increase in the length of the kidney (up to 15.6 cm) made it possible to suspect the presence of a doubling of the calyx-pelvic system according to echography.

The prevertebral parenchymal bridge of the horseshoe kidney can be mistaken for pre-aortic lymphadenopathy or thrombosis of the aortic aneurysm. Among the abnormally fused kidneys, the most common is the horseshoe kidney. Most often (in about 90% of cases) fusion is noted with the lower poles, much less often with the middle and upper segments.

Fig. 9. Horseshoe kidney (v). A volumetric formation located in front of the aorta, which has an oval shape in a longitudinal section.

Kidney dystopia is an abnormality in the development of the kidney, in which the kidney does not rise to its normal level during embryogenesis. Distinguish homolateral dystopia of the kidney, while the kidney is on its "own" side. Among homolateral dystopias, lumbar, iliac and pelvic dystopias are distinguished. Heterolateral dystopia is characterized by a lower detection of the kidney, but not on its own, but on the opposite side. In this case, variants of heterolateral dystopia with and without renal fusion are possible.

Nephroptosis, or pathological displacement of the kidney, occurs with congenital or acquired weakness of the ligamentous-supporting apparatus of the kidney, while the main role in the normal fixation of the kidney in the renal bed is played by the perirenal tissue.

With echographic detection of an abnormally located kidney, difficulties usually arise in the differential diagnosis of nephroptosis and dystopia. It should be remembered that the kidney with nephroptosis has a normal length of the ureter and a vascular pedicle located at the usual level (level L1-L2 of the lumbar vertebrae). Dystopic kidney has a short ureter and vessels extending from the large trunks at the level of the kidney.

The lobular contour of the kidney can be seen in children and young people as a manifestation of fetal lobulation, characterized by a flat surface of the kidney with the presence of grooves between the individual medullary pyramids. These changes should be distinguished from renal infarctions, which can be found in elderly patients with atherosclerotic renal artery stenosis.

Limited thickening of the parenchyma along the lateral margin of the left kidney (or in the region of the renal sinus margin), usually just below the inferior pole of the spleen, is found in almost 10% of patients. This anatomical variant, often referred to as the "camel hump" "humpback" kidney, is sometimes very difficult to distinguish from a true tumor of the kidney. These conditions are described as pseudotumors and are also variants of the normal structure of the kidney. One of the hallmarks of pseudo-tumor "bulging" of the parenchyma the preserved fetal lobulation of the kidney, in contrast to the tumor, is the preservation of the parallelism of the outer and inner contours of the parenchyma, the preservation of the normal echostructure of the parenchyma.

Atrophic and inflammatory changes in the kidneys

The kidneys respond to various inflammatory processes with heterogeneous sonographic changes. In acute pyelonephritis or glomerulonephritis in the early stages, the picture may be normal.

Later, an enlargement of the kidney is noted, with a predominant increase in the anteroposterior size of the kidney, as a result of which the echographic section of the kidney becomes round, and not oval, or bean-shaped, as is normal. There is a thickening of the parenchyma and a diffuse decrease in the echogenicity of the parenchyma. Edema causes an increase in size, and interstitial infiltration causes an increase in the echogenicity of the parenchyma with an increase in the clarity of its boundaries relative to the hypoechoic pyramids. This picture is called "knocked out medullary pyramids." In comparison with the neighboring parenchyma of the liver or spleen, the parenchyma of the kidney in such situations looks more echogenic than the parenchyma of the normal kidney.

Fig. 10. Acute pyelonephritis: an enlarged hypoechoic kidney with obliterated sinus and fluid levels in the renal pelvis.

This type of echographic changes is usually accompanied by acute renal failure. At the same time, the appearance of the syndrome of "protruding pyramids is based on ischemia of the renal cortex with shunting of blood through the venules of the medulla. Ischemia of the renal cortex develops as a result of interstitial edema, cellular infiltration of the interstitium and peripheral vasoconstriction. The echogenicity and sectional area of \u200b\u200bthe renal sinus also decreases as a result of resorption of renal sinus. renal sinus, compression of the renal sinus by a thickened parenchyma.

Fig. 11. Kidney enlargement in acute glomerulonephritis.

Interstitial nephritis can be caused by chronic glomerulonephritis, diabetic or urate nephropathy (hyperuricemia as a manifestation of gout or increased nucleic acid metabolism), amyloidosis or autoimmune diseases, but it is impossible to establish the true cause of the increased echogenicity of the parenchyma. Another sign of inflammation is the fuzzy border between the parenchyma and the collecting system.

Fig. 12. a, b Renal vein thrombosis, a Acute renal vein thrombosis in septic pyelonephritis: an enlarged kidney (K, cursors) with a fuzzy hypoechoic structure and a patchy-striped hypoechoic transformation of the central echo complex. C - atypical cyst, b Spectral analysis shows an extremely high IR of 0.96.

Para- and perinephritis is often visualized as zones with fuzzy, uneven contours of reduced echogenicity. With abscess formation, with purulent fusion of paranephria around the kidney, anechoic cavities are visualized, in which a suspension can be determined. A sharp decrease in the respiratory mobility of the kidney is determined. In the presence of viscous purulent contents in the case of "old", chronic paranephritis around the kidney, tumor-like masses of mixed echogenicity can be visualized. In this case, the borders of the kidneys will be indistinct, however, the purulent-necrotic masses themselves are extremely poorly differentiated from adipose tissue in the retroperitoneal space. An enlarged, deformed kidney is visible, with a sharply thickened, heterogeneous parenchyma, with distinct foci of destruction.The purulent process has spread to paranephritis with the development of purulent paranephritis (the hypoechoic zone around the kidney is marked with an arrow).

Fig. 13. Echogram of the kidney (1) with acute purulent paranephritis, which developed against the background of apostematous pyelonephritis. Paranephritis (2) is defined as a crescent-shaped zone of reduced echogenicity around the kidney.

Renal artery stenosis is the cause of peripheral infarction, and can also lead to a general decrease in the size of the kidney, which, however, can be a manifestation of recurrent or chronic inflammation.

Fig. 14. Shriveled kidney. Significant reduction in the kidney. Fuzzy border between the cortical and medullary layers.

The pronounced thinning of the parenchyma, found in the terminal stage of chronic nephritis, leads to atrophy of the kidney, which is often combined with degenerative calcification or calculi with a corresponding acoustic shadow.

Fig. 15. Reduction in the size of the kidneys with pyelonephritis (83.9 mm, cursors): foci of thinning of the parenchyma due to scarring, leading to the appearance of a wavy surface contour. C - flat cyst. Fine needle aspiration of a putative adrenal epithelium abscess.

An atrophied kidney can be so small that it cannot be detected sonographically. The associated decrease in excretory function can cause compensatory hypertrophy of the opposite kidney. With a one-sided small kidney, its PS index should be determined. If the PS index has a normal value, we can talk about congenital renal hypoplasia.

Although sonography does not allow differential diagnosis of inflammatory kidney disease, it is of great value in observing any renal inflammation during treatment, to exclude complications (eg, acute obstruction) and to perform percutaneous biopsy.

Kidney cysts

Renal cysts are anechoic and give distal enhancement. Additional criteria for the diagnosis of kidney cysts are the same as for liver cysts. Cysts are subdivided into peripheral cysts along the surface of the kidney,

Fig. 16. Peripheral cyst of the upper pole of the kidney.

Cysts of the parenchyma and cysts of the renal sinus, which in the future must be differentiated from the renal pelvis enlarged due to obstruction.

Fig. 17. Large cyst of the parenchyma.

The description of the cyst should include its size, as well as the approximate location (upper, middle, or lower third of the kidney). The detection of multiple kidney cysts is not of significant clinical significance, although regular re-examinations are recommended.

Fig. 18. Renal sinus cyst.

In contrast, adults with polycystic kidney disease have an uncountable number of cysts that continually increase in size. When the cysts grow large, the patient may complain of pain and a feeling of heaviness in the upper abdomen.

Fig. 19. Polycystic kidney disease.

In the future, polycystic disease causes kidney atrophy due to displacement and thinning of the organ parenchyma, which leads to the development of renal failure at a young age and requires dialysis or kidney transplantation.

Signs of obstruction and urinary tract. Differential diagnosis of urodynamic disorders

With obstruction of the urinary tract, the normal passage of urine through the urinary tract is disturbed, the fluid more or less completely fills the cavities of the renal calyceal system, as a result of which visualization of the calyceal system becomes possible.

The collecting system of the kidneys looks like a central complex of high echogenicity, which is intersected only by small thin vascular structures. With an increase in urine output after fluid intake, the renal pelvis can stretch and take the form of an anechoic structure. Similar manifestations can give various options for the development of the extrarenal pelvis. In both cases, the dilatation does not affect the large and small calyces. There are a number of pathological conditions in which the pyelocaliceal system is also visualized, but this is not caused by obstruction. These are acute and chronic renal failure in the stage of polyuria, chronic pyelonephritis, accompanied by sclerosis and deformation of the calyx and pelvic structures, renal tuberculosis with deformation, amputation, sclerosis of the calyces, formation of cavities, diabetic nephropathy with secondary pyelonephritic process, papillary necrosis, and subsequent necrosis the involvement of the cups in the sclerotic process. Vesico-pelvic reflux is the reason for visualization of the calyx-pelvic system during filling of the bladder (passive reflux), with active contraction of the detrusor (active reflux) with possible subsequent hydronephrotic transformation of the kidney. If the ultrasound diagnostics doctor is tasked with detecting reflux, it is advisable to examine the patient under conditions of normal water load, because the presence of fluid in the pelvis with increased urine output can lead to a false positive diagnosis of reflux. Ultrasound diagnostics of passive reflux is difficult, since dilatation of the pelvis occurs in almost all healthy people with an overstretching of the bladder. A presumptive diagnosis of passive reflux can be made if, after urination, the patient continues to dilate the PCS cavities for half an hour or more (assuming the patient is normally hydrated). Traditionally, ultrasound diagnosis of reflux is confirmed by ureterocystography.

Not always the expansion of the calyx-pelvic system indicates obstructive uropathy. The options for the development of the extrarenal pelvis have already been mentioned on the previous page. In addition, at the hilum of the kidney, prominent vessels can be seen heading towards the hypoechoic medullary pyramids. They can be mistaken for elements of the collecting system, but these vessels are more delicate and not as stretched as is the case with obstruction and expansion of the collecting system. Pyelectasis - ampullar enlargement of the renal pelvis with increased urinary excretion. It is characterized by the following sonographic features:

Triangular or cone-shaped hypoechoic mass in the renal pelvis

· Lack of expansion of the cups.

· Lack of dilatation of the ureter.

· CDI: absence of blood vessels.

Fig. 20. Pyelectasis (R), CDI. A large renal vein can be excluded from the list of diseases with which this condition should be differentiated.

Color Doppler will make it easy to determine if these structures are fast flowing blood vessels or a collecting system filled with immobile urine. Blood vessels appear as color-coded structures, the color of which depends on the direction and speed of blood flow, while slowly moving urine in the collecting system remains black. A similar flow rate differentiation principle can be used to distinguish cysts of the renal sinus, which do not require any treatment, from obstructive renal pelvis enlargement, which should be monitored or treated. Of course, these two states can exist simultaneously.

The literature discusses vasorenal and vasourethral conflicts that cause the presence of Frayly syndrome manifested by vascular compression of the calyces, anomalies of the vascular-ureteric relationship (pelvic-ureteric segment, retrocaval or retroilical location of the ureter, etc.) with the development of ureteral ureteral calyceloectomy, etc.)

Distinguishing these manifestations from the first (mild) degree of obstructive dilatation can be very difficult.

Distinguish obstruction "from the inside" of the calyx-pelvic system of kidney cavities. The most common obstruction is a calculus, less often - saline or inflammatory embolus, tumor. Obstruction occurs with various anomalies of the urinary system - ureteral strictures, stenosis of the pelvic-ureteric segment, high ureteral discharge etc. Below the site of obstruction, the urinary tract is not visualized against the background of perirenal tissue. Obstruction of the urinary system "outside" is most often caused by pathology of the retroperitoneal space. These are tumor lesions of the retroperitoneal lymph nodes, primary and metastatic tumors of the retroperitoneal space, retroperitoneal fibrosis, tumors of nearby organs ...

At the first (mild) degree of obstructive dilatation, the renal pelvis expands, but without distension of the calyces and visible thinning of the parenchyma.

Fig. 21. Violation of the outflow of urine, the first stage: a - the pelvis is filled with liquid (^), the necks of the cups are not yet stretched;

Second (moderate) degree of obstructive dilatation causes an increase in calyx filling as well as a decrease in parenchymal thickness. The bright central echo complex becomes rarefied and eventually disappears.

Fig. 22. Violation of the outflow of urine, the second stage. Expansion of the necks of the cups.

The third (pronounced) degree of obstructive dilatation is characterized by severe atrophy of the parenchyma due to compression and the presence of a cystic-enlarged pelvis.

Fig. 23. Violation of the outflow of urine, the third stage. Dilated cystic pelvis (^), distended calyx, significant thinning of the parenchyma.

At the fourth (terminal) stage of obstructive dilatation, the parenchyma is practically not visualized.

Fig. 24. Violation of the outflow of urine, terminal stage. The parenchyma is almost completely absent (^).

Sonography is unable to identify all causes of structural uropathy. Since in most cases the middle part of the ureter is closed by the gas located above it, the ureteral stone, unless it is stuck in the pelvic, ureteral, or peri-vesical region (in the upper or lower third of the ureter), is usually not visualized. Less common causes of ureteral obstruction are swelling of the bladder or uterus, swollen lymph nodes, and retroperitoneal fibrosis after radiation or idiopathic fibrosis such as Ormond disease. Latent obstruction can be found during pregnancy due to ureteral atony or urinary tract infection. In addition, the cause of ureteral obstruction can be bladder hyperextension as a result of neurogenic disorders and prostatic hypertrophy. In these cases, ultrasound examination should include examination of the bladder and search for an enlarged prostate in men.

Kidney infarction

Renal artery embolism or stenosis can cause focal kidney infarction. Clinical manifestations: flank pain, hematuria and proteinuria; fever, leukocytosis; nausea, vomiting Renal failure with oliguria may develop. After a few days, arterial hypertension appears.

In case of kidney infarction, its shape corresponds to the location of the vessels in the spleen parenchyma and is characterized by a wide base at the surface of the kidney and narrowing towards the hilum.

Ultrasound data:

· Segmental occlusion of the renal artery within 48 hours is manifested by the appearance of a zone of sharply reduced echogenicity, corresponding to the zone of infarction. In the acute stage of renal artery embolism, the kidney may have a normal echo structure, a wedge-shaped hypoechoic region may be determined, the apex of which is directed to the renal pelvis.

· From 7 to 21 days after a heart attack, a decrease in the infarction zone is observed, the boundaries of the infarction zone become more distinct. An echogenic triangular scar is formed, as a result of which a depression forms on the surface of the kidney, and the parenchyma layer decreases.

· In hemorrhagic infarction as a result of renal artery thrombosis, hemorrhage into the parenchyma leads to the appearance of a heterogeneous echogenic formation of irregular shape.

· CDE shows a lack of blood flow in the renal artery and sometimes a wedge-shaped defect in parenchymal perfusion.

· In the later stages of the scan, a decrease in the size of the kidney is noted. By the 35th day after a heart attack, the defined zone decreases sharply, its echogenicity increases. Remaining scars echo similar to kidney stones. You can distinguish them by the form of localization.

Fig. 25 a, b Renal infarction, a Wedge-shaped, clearly demarcated hypoechoic area b Magnification: the presence of a triangular avascular zone confirms the diagnosis of infarction. The patient was admitted with complaints of pain in the side.

Accuracy of ultrasound diagnostics: a reliable diagnosis of a fresh kidney infarction is impossible without the use of CDE, the accuracy of which reaches 85%. The diagnosis can be confirmed by ultrasound examination using echocontrast drugs or by CT angiography.

Urolithiasis disease

Currently, echography is the most accurate method of non-invasive diagnosis of nephrolithiasis. An important advantage of echography is the ability to visualize calculi of any chemical composition, including X-ray negative calculi of uric acid. At the same time, it is much more difficult to detect kidney stones (nephrolithiasis) than in the gallbladder, since echogenic kidney stones are often located within the collecting system of an equal echogenicity and do not give any echo signals to distinguish them from the surrounding structures. Difficulties in ultrasound diagnostics of calculi arise when the size of the calculus is small (3-4 mm). In the absence of enlargement, it is most important to detect an acoustic shadow from calculi or calcifications, such as in hyperparathyroidism.

Concretions in the dilated collecting system are a remarkable exception, as they are clearly visible in echo-negative urine as echogenic structures. The stone, which is the cause of the obstruction, is perfectly visualized against the background of fluid in the calyx-pelvic system

Fig. 26. Stone of the hepatic pelvis. The hepatic pelvis is hypoechoic and dilated. In the area of \u200b\u200bthe ureteropelvic junction, a stone with a high-amplitude echo signal (arrow) and a dorsal acoustic shadow (S) is found. K - kidney.

Depending on the composition, kidney stones can either fully conduct ultrasound, or reflect it so much that only the nearest surface in the form of an echogenic cup is visible.

In ultrasound practice, there is a significant overdiagnosis of calculi and sand in the kidney. This is due to the misinterpretation of the renal sinus image in the presence of small echo-positive structures in it. The differential diagnosis is carried out with arcuate arteries between the cortex of the kidney and the medullary pyramids (bright echo without a shadow), vascular calcifications in diabetic patients and calcified foci of fibrosis after renal tuberculosis. Calcifications in the vascular wall are characterized by the presence of two linear hyperechoic structures located on both sides of the formation. Finally, papillary calcifications may occur after prolonged use of phenacetin. For calcification of the papilla of the pyramid, the location in the projection of the papilla of the pyramid is characteristic.

Fig. 27. a, b. a Stone of the renal pelvis (not causing obstruction): a hyperechoic stone with a distal acoustic shadow (S; flickering artifact helps to confirm the diagnosis of stones), b Calcification of the apex of the papilla in diabetes mellitus: a bright echo at the apex of the medullary pyramid (arrow) with incomplete acoustic shadow (S).

The calculus is characterized by a rounded shape and a fairly clear acoustic shadow. However, all these differences very often do not allow differentiation of hyperechoic structures against the background of renal sinus tissue. To clarify the nature of the existing hyperechoic structures, it is recommended to conduct a pharmacoechographic test with lasix. If this hyperechoic structure is a calculus, then it will be located within the dilated with polyuria of the calyx-pelvis system. In this case, the acoustic "shadow" from a small stone surrounded by liquid may be absent.

Fig. 28. a-c. a Picture of the right kidney in the high transverse plane (K). An enlarged renal pelvis (P) is determined posterior to the artery in the absence of expansion of the proximal ureter. VC - inferior vena cava. B, c Expansion of the calyceal system in a patient with flank pain. Suspected biliary colic, b Dilated calyx (CA) communicating with a dilated and obstructed renal pelvis (PY). c Stone of the proximal ureter, causing obstructive expansion of the calyces. The picture shows anechoic formations in the central echo complex. The upper formation is an enlarged calyx neck. Expansion of the calyx neck greater than 5 mm (here 11 mm) indicates obstruction. The lower formation is an enlarged renal pelvis.

Large coral stones are difficult to diagnose if they produce distal shadow and, due to their echogenicity, can be mistaken for a central echogenic complex.

If kidney stones are displaced and pass from the intrarenal collecting system to the ureter, they may, depending on their size, pass asymptomatically or colicky into the bladder, or become stuck and obstruct the ureter. Clinical signs of urolithiasis: acute severe attacks of abdominal pain caused by a kidney stone or, in rare cases, a blood clot. The release of urine into the perirenal space leads to the formation of urinoma.

Fig. 29. a, b Renal colic against the background of the uretero-pelvic junction stone. a Hydronephrotic kidney (K) with a dilated, fluid-filled renal pelvis and transudate (urinoma, FL). b Ureteropelvic calculus (arrow, U) and dilated renal pelvis (P). The picture was taken in the upper oblique longitudinal plane of the abdominal cavity along the right ureter.

Among doctors of ultrasound diagnostics, it is widely believed that it is impossible to visualize calculi in the ureter. Indeed, at the usual level of diuresis, the ureter practically does not differentiate from the retroperitoneal tissue. However, in the presence of urostasis, or in artificial polyuria, visualization of the ureter is possible. With pronounced dilatations of the ureter (more than 0.7-0.8 cm), the ureter is visualized all the way to the bladder in a patient of any build.

Fig. 30. a, b Urolithiasis with calculus (arrow) defined in the prevesical part of the ureter (U). a B-mode image: high-amplitude echo with incomplete acoustic shadow. A picture in the lower transverse-oblique plane of the abdominal cavity, b CDE, performed 4 days later: a stone in the orifice of the ureter, not causing its obstruction; stream of urine (red); faint flickering artifact in the acoustic shadow of the stone.

The ureter is better visualized when viewed in the frontal plane with the patient on the side. With minor dilations (in this case, the ureter is visualized as a hypoechoic thin strip of 4-6 mm), as a rule, it is very difficult to visualize the prevesical section, since after "crossing" with the iliac vessels, the ureter deviates quite sharply posteriorly, to the posterior wall of the bladder. Therefore, with a large filling of the bladder, visualization of the prevesical part of the ureter is sharply difficult, because in such conditions, the ureter deviates even more posteriorly. When examining the prevesical part of the ureter, it can be recommended to force diuresis as much as possible (for tighter filling of the ureter with fluid) and not to overfill the bladder - up to a maximum of 100-150 ml. At the same time, the bladder is slightly filled.

In addition to diagnosing obstructive uropathy, sonography can help rule out other causes of abdominal pain, such as pancreatitis, colitis, and fluid accumulation.

Fig. 31 a, b Common causes of chronic urinary tract obstruction (UTI). a Metastatic tumor in the small pelvis (ovary, uterus; in this picture: rectal carcinoma), b Bladder carcinoma (urothelial carcinoma, arrows), often localized near the orifice of the ureter. The differential diagnosis includes metastatic prostate carcinoma. U - ureter, IA - iliac artery, B - bladder.

Kidney tumors

Unlike fluid-filled cysts, kidney tumors have internal echoes, and no or weak acoustic amplification is detected behind them.

Organ-specific benign kidney tumors include adenomas (or oncocytomas). Angiomyolipomas, urothelial papillomas. Benign renal tumors (fibromas, adenomas, hemangiomas) are quite rare and do not have a universal sonographic morphology.

Only angiomyolipoma, a benign mixed tumor that includes blood vessels, muscle and adipose tissue, has specific sonographic features at an early stage that can distinguish it from a malignant process. Small angiomyolipomas have the same echogenicity as the central echo complex, and are clearly limited. However, Derchi L. et al. (1992) described a case of renal adenocarcinoma giving almost identical ultrasound semiotics. With an increase in size, angiomyolipoma becomes heterogeneous, which complicates its differentiation from malignant tumors. Angiomyolipoma has a slow (several mm per year) non-invasive growth. Small angiomyolipomas of the parenchyma are echographically similar to calcifications in the parenchyma, however, in the presence of angiomyolipomas, both the anterior and posterior contours of the formation are visualized equally well. In the presence of calcification, ultrasonic signals are reflected from the anterior surface of the formation, then an acoustic shadow is determined. The formation contour farther from the scanning surface of the sensor is not visualized. Angiomyolipomas of the renal sinus are echographically detected only when the tumor is large enough, in the presence of deformation of the central echo complex. Angiomyolipomas can be multiple in nature. Most often, multiple angiomyolipomas in combination with multiple cysts are determined in tuberous sclerosis - a congenital disease characterized by the development of specific granulomas in the brain, with a clinic of oligophrenia and epilepsy, as well as a multiple organ tumor process.

A small renal cell tumor (hypernephroma) is often isoechoic compared to the rest of the renal parenchyma. Only with further growth does the hypernephroma become heterogeneous and occupy space with the bulging of the kidney contour.

Fig. 32. Hypernephroma. Large tumor of the upper pole of the kidney with hypoechoic and hyperechoic inclusions.

If hypernephroma is detected, it is necessary to carefully examine the renal veins, the corresponding locations of the lymph nodes, and the contralateral kidney to identify neoplastic changes. Renal cell carcinoma in about 5% of cases has bilateral growth; an advanced tumor can invade the vessels and spread along the course of the renal and inferior vena cava. If the tumor invades the capsule and spreads to the adjacent psoas muscle, the kidney loses its ability to mix aspirated.

Kidney leiomyomas are rare. It is assumed that renal leiomyomas develop from the muscular elements of the vascular wall of the renal sinus. Echographically, leiomyomas are represented by a solid volumetric structure with clear even contours of lower echogenicity than the renal parenchyma.

Kidney lymphomas cause diffuse enlargement of an organ with diffuse lesions of the parenchyma with multiple small hypoechoic formations with a fuzzy outline, or are visualized as hypo- and or are visualized as hypo- and anechoic large rounded foci with a thin capsule and a clear distal pseudo-enhancement. In this case, it is necessary to carry out a differential diagnosis with simple renal cysts. In most cases, renal lymphoma is an organ manifestation of a general disease and usually appears in the later stages of the process. Often at this stage of the disease, packets of altered lymph nodes are visualized.

Clear cell adenoma is not echographically differentiated from kidney cancer. Unfortunately, often the diagnosis of this benign tumor is established only during autopsy, after removal of the organ. The cystic form of adenoma with ultrasound has the shape and structure of a honeycomb. In this case, it is necessary to carry out a differential diagnosis with a multilocular cyst and a cystic form of hypernephroid cancer.

The left adrenal gland lies anteriorly and medially (not above) from the superior pole of the kidney. The right adrenal gland is positioned posterior to the pole, towards the inferior vena cava. In adults, the adrenal glands are not visible or sometimes poorly discernible in the perirenal tissue. Hormone-producing adrenal tumors, such as adenoma in Cohn's syndrome or hyperplasia in Cushing's syndrome, are usually too small to be detected by sonography. Only a clinically significant pheochromocytoma, usually already several centimeters in diameter, can be detected sonographically in 90% of cases. Sonography is more important for detecting metastases in the adrenal glands.

Metastases are usually seen as hypoechoic foci between the superior pole of the kidney and the spleen or the inferior surface of the liver, respectively, and should be differentiated from atypical renal cysts. Hematogenous spread of metastases is due to strong vascularization of the adrenal glands and can occur in bronchogenic cancer, as well as in breast and kidney cancer. Whether or not a mass in the adrenal gland is malignant cannot be decided on the basis of its echogenicity. Before performing fine-needle biopsy, pheochromocytoma should be excluded to avoid hypertensive crisis.

Echography of renal transplant patients

Renal grafts can be in any of the iliac fossae and connected to the iliac vessels.

Typically, the graft is placed in the iliac fossa of the recipient's contralateral side. The kidney is deployed in such a way that the posterior surface of the kidney is facing anteriorly, and the anterior surface is facing posteriorly. The renal vein anastomoses with the external iliac artery, the renal vein with the internal iliac vein. The orientation of the hilum of the graft is opposite to that of the hilum of a normal kidney. The ureter of the transplanted kidney is connected to the bladder or, rarely, to the recipient's ureter. The kidney is located in an oblique direction, retroperitoneally, in front of m. psoas and iliac veins.

Similar to dystopic kidneys, grafts are examined in two views, but the transducer is placed laterally in the lower abdomen. Since the transplanted kidney is located directly behind the abdominal wall, intestinal gas does not interfere with the study.

Early diagnosis of graft rejection or other complications is essential. The norm for a renal graft after surgery is an increase in size of up to 20%.

A very important indicator for identifying echographic signs of graft pathology is the ratio of the anteroposterior size of the kidney to its length. Normally, this ratio is 0.3-0.54, while the value of the anteroposterior size of the kidney does not exceed 5.5 cm. Accordingly, the transverse section of the transplanted kidney normally retains a bean-shaped or oval shape. For an accurate assessment of the size of the kidney graft, first examine in a longitudinal section and select the position of the sensor so that the length of the organ is maximized. Then the sensor is turned slightly. This two-stage technique gives confidence that the length measurement data are not underestimated, and this can lead to an erroneous conclusion about an increase in volume (simplified formula: vol \u003d AxB Cx0.5) during subsequent control studies.

Compared to normal kidneys, the graft cortex looks thicker, and the echogenicity of the parenchyma is reduced so much that the medullary pyramids become clearly visible. Progressive inflammatory infiltration should be excluded by conducting a series of control ultrasound examinations for a short time immediately in the postoperative period. In the future, in the renal transplant, the clarity of its outer contour and the border between the parenchyma and the collecting system should be assessed.

An open renal pelvis or a slightly dilated collecting system (first stage) can be observed due to functional failure of the renal graft and does not require intervention. Normally, in the postoperative period, moderate dilatation of the graft PCS is permissible, apparently associated with edema of the ureteroneocystoanastomosis. However, this dilation should not be significant. Stretching of urine should be documented.

Fig. 33 Renal allograft (K) on the right side of the lower abdominal floor. Arrows: dilated, fluid-filled calyx-pelvis system. C - renal pillars, MR - hypoechoic pyramids of the medulla

The complications of a transplanted kidney include acute tubular necrosis, acute graft rejection, obstructive processes, vascular complications, the formation of various leaks, hematomas, abscesses as a result of anastomoses failure and rejection crises.

An indistinct boundary between the parenchyma and collecting system and a slight increase in volume can be signals of the danger of an incipient rejection. Acute graft rejection develops within the first few weeks after transplantation (however, the use of immunosuppression can significantly change the timing of acute rejection). Cases of the development of acute rejection up to 5 years after transplantation have been described. Histologically, in acute rejection, cellular mononuclear infiltration and edema of the renal interstitium are revealed. The vascular bed changes significantly: the wall of blood vessels (arteries and arteriopes) sharply thickens with the development of hemorrhages. Heart attacks, thrombosis. Echographically, the graft increases in size, mainly due to the anteroposterior size, while in transverse scanning the shape of the section becomes rounded. There is a rapid increase in renal graft volume (more than 25% in two weeks). The ratio of the anteroposterior size to the length of the kidney exceeds 0.55. The anteroposterior size of the kidney increases by more than 5.5 cm. There is an increase in the sectional area of \u200b\u200bthe pyramids, which corresponds to interstitial peritubular edema. The echogenicity and cross-sectional area of \u200b\u200bthe central echo complex corresponding to the renal sinus is reduced by a decrease in the number of fat cells in the renal sinus. Hypo- and anechoic areas appear in the parenchyma, corresponding to the zones of edema, hemorrhage, and necrosis. In general, the graft cortex becomes more echogenic due to cellular infiltration. For a reliable comparison, reproducible longitudinal and cross-sections should be selected for measurement and documentation. After transplantation, the intensity of immunosuppressive therapy gradually decreases, the time intervals between control ultrasound examinations can be increased.

Acute tubular necrosis develops in almost 50% of transplanted kidneys. The pathogenetic factors in the development of acute tubular necrosis of the graft are the syndrome of disseminated intravascular coagulation and hypotension, which occur during storage of the graft before surgery. Clinically, acute tubular necrosis is manifested by the appearance of symptoms of acute renal failure. Very rarely, echographically with acute tubular necrosis, there is an increase in pyramids and a decrease in their echogenicity. Most often, acute tubular necrosis is not echographically manifested, however, the absence of echographic changes in the development of acute renal graft failure does not "remove" the diagnosis of acute tubular necrosis.

Urinary obstruction is an equally common complication and, depending on the severity, may require temporary drainage to prevent damage to the renal parenchyma. Measurements of the pelvis and cross-sections should be taken so that subsequent studies do not miss any dynamics requiring therapeutic intervention. Phenomena of PCS dilatations develop as a result of obstruction of the ureter "from the inside" by a blood clot, stone, as a result of stricture formation, as well as squeezing of the ureter by fluid leaks that form near the graft when the anastomoses fail.

Lymphocele can develop as a complication of kidney transplantation. Lymphocele is usually found between the lower pole of the renal graft and the bladder. But it can be anywhere near the graft. Fluid leaks are more often formed as a result of anastomoses failure, with acute graft rejection. Reveal hematomas, lymphoid streaks, seromas, urinomas. Fluid streaks may suppurate with the formation of abscesses. More often, the echographic picture of the leak does not allow differentiating its composition.

Vascular reactions are defined as venous thrombosis, complete or partial arterial occlusion. In acute venous thrombosis, the kidney rapidly and sharply increases in size, the parenchymal cortex becomes thicker, its echogenicity decreases sharply, and corticomedullary differentiation disappears. In the parenchyma of the kidney, multiple hypoechoic areas appear, corresponding to areas of hemorrhage. Changes are similar to changes in acute rejection, therefore, in conclusion, it is more correct to make two presumptive diagnoses. Occlusion of the main trunk of the renal artery, as a rule, does not give any echographic changes. Measurement of the resistance index (RI) of the blood supplying vessels of the kidney during Doppler ultrasound examination provides additional information about the condition of the renal transplant. Recently, the Doppler study of the graft vessels has been considered very promising for determining rejection crises, determining the occlusion of the renal vessels, as well as the specifics of morphological changes that occur in the pathology of the graft. A pronounced increase in vascular resistance is observed with a crisis of renal transplant rejection. At the same time, there is a moderate decrease in the maximum systolic blood flow velocity and a significant decrease or disappearance of the diastolic flow. A pronounced rejection reaction is characterized by a significant decrease in systolic blood flow, a practical absence of blood flow in the diastole phase, and an increase in the acceleration time. The reaction of rejection of weak or moderate severity is characterized by a moderate decrease in systolic blood flow velocity (mainly along the interlobular arteries), a decrease in diastolic blood flow with a gentle slope angle during the entire diastole period.