X-ray signs of kidney disease

The tactics of radiological examination, i.e. the choice of radiological methods and the sequence of their application, are developed taking into account the anamnesis and clinical data. To a certain extent, it is standardized, since in most cases the doctor deals with typical clinical syndromes: pain in the kidney area, macrohematuria, urination disorders, etc. This circumstance justifies the use of typical schemes for examining patients, and such schemes are given below. However, the doctor's responsibility includes a thoughtful analysis of the characteristics of the course of the disease in a particular patient and making the necessary adjustments to the general schemes.

Renal colic

The patient's condition is serious. He has an attack of cramping pain in the kidney area, often radiating to the lower abdominal cavity and pelvic area. The pain syndrome is often accompanied by nausea or vomiting, intestinal paresis. Frequent urination is sometimes observed. The patient is prescribed thermal procedures, painkillers. The attending physician - urologist or surgeon determines the indications for radiological examination and the time of its implementation.

Renal colic is caused by stretching of the renal pelvis due to obstruction of urine outflow, which can be caused by blockage or compression of the upper urinary tract. In the vast majority of cases, the cause of blockage is a stone, but it can also be caused by a blood clot or mucus. Compression of the ureter can be caused by a tumor. The research tactics used in such cases are shown in the diagram.

Examination of a patient with renal colic should begin with sonography. Colic is characterized by dilation of the renal pelvis on the side of the pain attack. A stone is usually found in the renal pelvis or ureter. It is easier to detect a stone in the renal pelvis. Concrements larger than 0.5 cm are visualized as echo-positive formations with clear outlines. An acoustic shadow is noted behind the stone. Stones smaller than 0.5 cm do not give such a shadow, and they are difficult to distinguish from mucus or purulent masses. In such a situation, repeated sonography helps. It is difficult to diagnose a stone in the ureter. Usually this is possible only if it is localized in the pelvic part of the ureter within 4-5 cm from its mouth.

If the sonography results are unclear, a general radiograph of the kidneys and urinary tract is performed. Most kidney stones consist of inorganic salts - oxalates or phosphates, which intensively absorb X-rays and produce a discernible shadow on the images. By analyzing the radiograph, the number of stones, their location, shape, size, and structure are determined. In 2-3% of cases, kidney stones consist mainly of protein substances - fibrin, amyloid, cystine, xanthine, bacteria. They poorly absorb radiation and are not visible on radiographs.

The size of urinary stones may vary. A large stone sometimes repeats the shape of the calyces and pelvis and resembles coral ("coral" stone). Small stones have a round, polygonal, ovoid or irregular shape. In the bladder, the stone gradually takes on a spherical shape. It is important not to confuse urinary stones with stones and petrifications of a different nature - with gallstones, calcified small cysts, lymph nodes in the abdominal cavity, etc. Doubts often arise when detecting venous stones (phlebolites) in the pelvis. It should be taken into account that they have a regular spherical shape, small size, a transparent center and a clear concentric structure, and are located mainly in the lower lateral parts of the pelvis.

The next stage of examination of a patient with renal colic is urography. It confirms the presence of a stone in the urinary tract and specifies its location. At the same time, urography makes it possible to assess the anatomical condition of the kidneys, the type of pelvis, the degree of expansion of the calyces, pelvis, and ureter.

In case of X-ray negative stones, urograms reveal a filling defect of the urinary tract with clear contours. Sometimes, in case of severely impaired urine outflow, urograms reveal an enlarged kidney with an enhanced nephrographic effect without contrasting the renal pelvis and calyces - the so-called large white kidney. Such an urogram shows that the kidney function is preserved. If the function is lost, then the kidney shadow does not increase during urography.

Renography is of great importance in determining the functional state of the kidneys and especially in assessing their reserve capacity. On the side of the affected kidney, the renographic curve has a constantly ascending character - an obstructive type of curve. The steeper the rise of the curve, the more the kidney function is preserved. In order to distinguish obstructive uropathy from functional (dilatational), the above-described test with the introduction of a diuretic is used in renography.

When planning an operation - surgical removal of occlusion - it is advisable to perform renal angiography. This method allows studying the architecture of the vessels, which is important for resection of the kidney, nephrotomy. If the renal artery is narrowed by more than 50% of its normal diameter, then the loss of kidney function is usually irreversible.

Radiation studies are widely used to monitor the effectiveness of various interventions on the kidneys. In recent years, a method for crushing stones in the body has been developed - extracorporeal shock wave lithotripsy.

Sonograms and radiographs help evaluate the results of the intervention and identify possible complications, in particular intrarenal hematomas. In surgical removal of stones, ultrasound localization directly on the operating table is of some use.

Obstruction or compression of the upper urinary tract leads to expansion of the renal pelvis. Initially, the renal pelvis enlarges - pyelectasis, then the calyces expand - hydronephrosis, but isolated expansion of one or more calyces is also possible. If the cause of the urine outflow disorder is not eliminated, then persistent and increasing expansion of the entire renal pelvis is observed, ultimately leading to atrophy of the renal parenchyma. This condition is called hydronephrotic transformation, or hydronephrosis.

Hydronephrotic transformation of the kidney is determined using radiation methods - sonography, urography, scintigraphy. Signs of hydronephrosis are an enlarged kidney, expansion of the calyceal-pelvic complex up to its transformation into a large cavity with a smooth or wavy internal surface, atrophy of the renal parenchyma, a sharp decrease or loss of kidney function.

The cause of hydronephrosis is usually a stone blocking the ureter. If the stone is not found, angiography is prescribed to exclude other causes, primarily an accessory renal artery compressing the ureter.

Kidney and bladder trauma and macrohematuria

Kidney injuries are often combined with trauma to adjacent organs and bones, so it is advisable to begin the examination of the victim with a general fluoroscopy and radiography, which determine the condition of the lungs, diaphragm, spine, ribs, and abdominal organs. Isolated kidney injuries include its contusion with the formation of a subcapsular hematoma, disruption of the integrity of the calyceal-pelvic system, rupture of the renal capsule with the formation of a retroperitoneal hematoma, crushing or avulsion of the kidney.

On a survey radiograph, a subcapsular hematoma of the kidney is manifested by an increase in the shadow of the organ. A sonogram allows one to detect a hematoma and judge its location and size. In case of a relatively minor kidney injury, the primary examination, in addition to survey images, is intravenous urography. First of all, it allows one to determine the degree of dysfunction of the damaged kidney. On urograms, one can detect a volumetric formation (hematoma), the presence of urinary leaks, indicating a rupture of the renal pelvis.

However, the most informative method of examining patients with kidney injuries is still computed tomography. It makes it possible to assess the condition of all abdominal organs and identify a perirenal hematoma, rupture of the kidney capsule, disruption of the integrity of the fascia, and accumulation of blood in the abdominal cavity. A kidney rupture with the outpouring of blood and urine into the perirenal tissue leads to the disappearance of the kidney shadow on the plain radiograph and the contour of the large lumbar muscle on the affected side. Metallic foreign bodies are clearly visible during radiography.

If the condition of the calyces and pelvis cannot be determined based on the results of sonography and tomography, then urography is used. If the calyces and pelvis are intact, their contours are smooth. In the case of a rupture of the wall of the pelvis or calyx, accumulations of contrast agent are observed outside them, in the thickness of the renal tissue, as well as deformation of the calyceal-pelvic complex. In addition, weak and late release of contrast agent is noted. If damage to the ureteropelvic junction is suspected, a combination of CT and urography is especially valuable. They make it possible to distinguish a complete rupture of the ureter from its rupture, in which case it is possible to perform ureteral stenting and thus limit ourselves to conservative therapy.

In case of macrohematuria and questionable results of urography and CT, angiography is indicated, which reveals direct signs of damage to blood vessels and extravasation of contrast agent when they rupture. The area of damage can be clarified on the nephrogram.

In case of bladder trauma, the leading role is played by X-ray examination. General images of the pelvis are especially important in case of extraperitoneal bladder ruptures, since they are usually associated with pelvic bone fractures. However, artificial contrast of the bladder - cystography - is of primary importance. Contrast agent is introduced into the bladder through a catheter in the amount of 350-400 ml. In case of intraperitoneal rupture, the contrast agent flows into the lateral canals of the abdominal cavity and changes its position when the patient's body position changes. For extraperitoneal rupture, the contrast agent typically passes into the perivesical tissue, where it creates shapeless accumulations in front of and on the sides of the bladder. Pelvic and perineal trauma may be accompanied by rupture of the urethra.

A direct way to quickly and reliably recognize this damage and determine the location of the rupture is urethrography. A contrast agent, introduced through the external opening of the urethra, reaches the rupture site and then forms a leak in the paraurethral tissues.

Inflammatory kidney diseases

Pyelonephritis is a non-specific inflammatory process with predominant damage to the interstitial tissue of the kidney and its calyceal-pelvic system. X-rays and sonograms show a slight increase in the affected kidney.

Computer tomograms can detect thickening of the renal fascia and accumulation of exudate in the perirenal space. Dynamic scintigraphy almost always reveals a decrease in the rate of excretion of the radiopharmaceutical, i.e. a decrease in the steepness of the decline of the third segment of the renogram curve. Later, flattening of the renographic peak and stretching of the first and second segments are detected.

Urography is performed on patients with pyelonephritis. The contrast agent is usually excreted by the affected kidney weakly and slowly. Initially, a barely noticeable deformation of the calyces can be noted. Then their expansion (hydronephrosis) is observed. Dilation of the renal pelvis also occurs. Its size of more than 2-3 cm indicates pyelectasis, but unlike pyelectasis and hydronephrosis, when the ureter or pelvis is blocked by a stone, the outlines of the calyces and pelvis become uneven. The process can progress to the pyonephrosis phase. At first glance, its urographic picture resembles that of hydronephrotic deformation of the kidney, but here too the distinctive feature is the eroded contours of the resulting cavities.

Pyelonephritis may be complicated by the development of an abscess, carbuncle, or paranephritis. Sonography and angiography allow us to directly identify the abscess or carbuncle cavity. The contours of the cavity are initially uneven, with fragments of necrotic tissue in the lumen and a zone of compacted tissue around it. In paranephritis, an infiltrate is observed in the perirenal space. It should be noted that the upper posterior paranephritis is actually a subdiaphragmatic abscess, so fluoroscopy and radiography of the lungs can show deformation and limited mobility of the diaphragm on the affected side, blurred outlines, the appearance of small atelectasis and foci of infiltration at the base of the lung and fluid in the pleural cavity. On a general radiograph of the abdominal organs, the outline of the large lumbar muscle disappears.

Among nephrological diseases, glomerulonephritis is of the greatest importance; other diffuse lesions of the renal parenchyma are less common: cortical necrosis, nodular periarteritis, systemic lupus erythematosus, etc. The primary method of examination for lesions of this kind is sonography. It allows one to detect changes in the size of the kidneys (increase or decrease), expansion and compaction of the cortical layer. As a rule, the lesion is bilateral, relatively symmetrical, and no signs of hydronephrosis are detected, which are so characteristic of pyelonephritis. Other methods of radiation examination for kidney lesions of this group are of limited importance. An exception is renography. In this case, it is necessary to pay attention to the following: since glomerulonephritis primarily affects the glomeruli, the study should be performed with ^99m Tc-DTPA, which is secreted by the glomeruli, whereas in pyelonephritis, preference is given to hippuran and ^99m Tc-MAG-3, which are secreted mainly by the tubular epithelium. In patients with glomerulonephritis, the renogram curve gradually flattens as the severity of kidney damage increases.

Chronic pyelonephritis, glomerulonephritis, long-term arterial hypertension and atherosclerosis of the renal artery lead to nephrosclerosis - replacement of the renal parenchyma with connective tissue. The kidney decreases in size, shrinks, its surface becomes uneven, its function decreases sharply. Reduction of the kidney is recorded on radiographs, urograms, sonograms. CT shows that the reduction occurs mainly due to the parenchyma. Radionuclide examination shows a decrease in renal plasma flow. A flattened, almost horizontal line can be observed on the renogram. Angiography demonstrates a picture of depleted renal blood flow with a reduction of small arterial renal vessels (the "burnt tree" picture).

Thus, the tactics of radiological examination in diffuse kidney lesions is reduced to a combination of radionuclide examination of renal function with sonography or CT. Urography and angiography are performed as additional studies to clarify the state of the calyceal-pelvic complex and renal vessels.

Specific inflammatory lesions include renal tuberculosis. During the period of fresh seeding of the kidney with tuberculous granulomas, radiation methods do not bring real benefit, only renal dysfunction can be determined during renography. Later, fibrous changes and cavities in the renal parenchyma occur. On sonograms, the cavern resembles a renal cyst, but its contents are heterogeneous, and the surrounding tissue is compacted. When the inflammation passes to the calyceal-pelvic system, unevenness of the contours of the calyces occurs. Later, cicatricial deformation of the calyces and pelvis occurs. If changes are not clear during urography, retrograde pyelography should be performed. The contrast agent from the calyces penetrates into the caverns located in the renal tissue. Damage to the ureters leads to unevenness of their outlines and shortening. If the process has spread to the bladder, its image also changes: its asymmetry, reduction, and flow of contrast agent back into the ureter (vesicoureteral reflux) are observed.

The volume and localization of tuberculous lesions in the kidney can be best determined by CT. Arteriography is very useful when planning surgical intervention. In the arterial phase, deformation of small arteries, their ruptures, and uneven contours are detected. The nephrogram clearly shows areas that are not functioning. To obtain an idea of the nature of renal vascularization, power Doppler mapping is now increasingly used instead of angiography, although the doctor receives similar data when performing CT with amplification.

Nephrogenic arterial hypertension

A clear and easily detectable manifestation of this syndrome is high blood pressure. It is persistent and does not respond to treatment until the cause of hypertension is eliminated. And there can be two reasons. The first is a violation of the arterial blood flow to the organ. It can be caused by narrowing of the renal artery due to fibromuscular dysplasia, atherosclerosis, thrombosis, kink in nephroptosis, aneurysm. This form of nephrogenic hypertension is called vasorenal or renovascular. The second reason is a violation of intrarenal blood flow in glomerulonephritis or chronic pyelonephritis. This form of the disease is called parenchymatous.

The basis for conducting a radiological examination is high arterial hypertension resistant to drug treatment (diastolic pressure above 110 mm Hg), young age, positive pharmacological tests with captopril. The tactics of radiological examination are generally presented in the scheme below.

Duplex sonography allows to establish the position and size of the kidneys, study the pulsation of their arteries and veins, detect lesions (cysts, tumors, scars, etc.). Renography provides a study of the blood flow in the kidneys and a comparative assessment of the function of the glomeruli and tubules of the right and left kidneys. It is also necessary to remember the possibility of a renin-secreting tumor (pheochromocytoma). It is detected using sonography, AGG and MRI.

Renal arteriography most clearly reflects lesions of the renal artery - its narrowing, kinking, aneurysm. Arteriography is mandatory when planning surgical, including radiological interventional, intervention. It is performed mainly using DSA. Due to venous access, this study can be carried out even in outpatient settings. After therapeutic interventions on the renal artery (transluminal angioplasty), it is DSA that is used.

In recent years, ultrasound examination of renal blood flow using the power Doppler mapping method has been rapidly developing and successfully used in examining patients with vasorenal hypertension, which in some cases allows avoiding such an invasive examination as X-ray angiography. MR angiography performed in several projections, especially with the use of paramagnetics and three-dimensional image reconstruction, allows for precise determination of the narrowing of the renal artery over the first 3 cm from its mouth and assessment of the degree of vessel occlusion. However, it is difficult to judge the condition of more distal sections of the arteries based on the results of MRA.

Tumors and cysts of the kidneys, bladder, prostate gland

A volumetric formation in the kidney, bladder or prostate gland is one of the most frequently detected syndromes of damage to these organs. Cysts and tumors can develop latently for a long time, without causing pronounced clinical symptoms. Laboratory tests of blood and urine are of very relative importance due to their non-specificity and heterogeneity of results. It is not surprising that the decisive role in identifying and establishing the nature of the volumetric process is given to radiation methods.

The main methods of radiological diagnostics used in patients with suspected space-occupying lesions are sonography and CT. The first is simpler, cheaper and more accessible, the second is more accurate. Additional data can be obtained using MRI, Doppler mapping and scintigraphy. Angiography may be useful when planning surgical interventions on the kidney. It is also used as the first stage of intravascular examination during renal artery embolization before nephrectomy.

On sonograms, a solitary cyst appears as a rounded, echo-negative formation devoid of internal echostructures. This formation is sharply defined and has smooth contours. Only rarely, with hemorrhage into the cyst cavity, can delicate structural formations be found in it. A large cyst or a cyst located near the renal sinus can cause deformation of the calyces or pelvis. A peripelvic cyst sometimes resembles an expanded pelvis, but in the latter, a rupture in the contour is visible at the transition of the pelvis into the ureter. A retention cyst and echinococcus are in some cases indistinguishable. Internal echostructures and calcification in the fibrous capsule indicate a parasitic cyst. The cyst is distinguished as a homogeneous and relatively low-density rounded formation with smooth, sharp contours. It is possible to establish the localization of the cyst in the parenchyma, under the capsule, near the pelvis. A parapelvic cyst is located in the renal hilum and usually grows outward. Parasitic cysts have a visible capsule. CT, like ultrasound, is used to puncture cysts and renal tumors.

Urograms mainly reveal indirect symptoms of a cyst: displacement, compression, deformation of the cups and pelvis, sometimes amputation of the cup. A cyst can cause a semicircular depression on the wall of the pelvis, lead to an elongation of the cups, which seem to bend around the neoplasm. In the nephrographic phase, linear tomograms can display a cyst as a rounded defect in the contrast of the parenchyma. The possibilities of radionuclide research in the diagnosis of cystic disease are limited. Only fairly large cysts, larger than 2-3 cm, are visualized on renal scintigrams.

The tactics of examining patients with kidney tumors initially do not differ from those for cysts. At the first stage, it is advisable to perform sonography. Its resolution is quite high: a tumor node measuring 2 cm is detected. It stands out against the general background as a round or oval formation of irregular shape, not quite uniform in echogenic density. The outlines of the node, depending on the type of its growth, can be quite clear or uneven and blurred. Hemorrhages and necrosis cause hypo- and anechoic areas inside the tumor. This is especially characteristic of Wilms' tumor (a tumor of embryonic nature in children), which is characterized by cystic transformation.

The further course of examination depends on the sonography results. If it does not provide data confirming the presence of a tumor, then CT is justified. The fact is that some small tumors differ little in echogenicity from the surrounding parenchyma. On a CT scan, a small tumor is visible as a node if its size is 1.5 cm or more. In terms of density, such a node is close to the renal parenchyma, so it is necessary to carefully analyze the image of the kidney on a number of sections, identifying the heterogeneity of its shadow in any area. Such heterogeneity is due to the presence of denser areas in the tumor, foci of necrosis, and sometimes lime deposits. The presence of a tumor is also indicated by such signs as deformation of the kidney contour, an indentation on the calyx or pelvis. In unclear cases, they resort to the enhancement method, since in this case the tumor node is determined more clearly.

Large neoplasms are clearly visible in CT, especially when performed using the enhanced method. The criteria for tumor malignancy are the heterogeneity of the pathological formation, the unevenness of its contours, the presence of calcification foci, and the phenomenon of tumor shadow enhancement after intravenous administration of a contrast agent. The renal sinus is deformed or not defined: it is possible to register the spread of tumor infiltration along the vascular pedicle. MRI of renal tumors and cysts produces similar images, but its resolution is somewhat higher, especially when using a contrast agent. Magnetic resonance tomograms more clearly show the transition of the tumor to vascular structures, in particular to the inferior vena cava.

If a tumor is not detected by computed tomography and magnetic resonance imaging, but there is a slight deformation of the renal pelvis and the patient has hematuria, then there is reason to use retrograde pyelography to exclude a small tumor of the renal pelvis.

In case of medium and large tumors, it makes sense to perform urography after sonography. Even on a general radiograph, an enlarged kidney and deformation of its contour, and sometimes small deposits of calcium in the tumor can be detected. On urograms, the tumor causes a number of symptoms: deformation and displacement of the calyces and pelvis, and sometimes amputation of the calyces, uneven contours of the pelvis or a filling defect in it, deviation of the ureter. On a nephrotomogram, the tumor mass produces an intense shadow with uneven outlines. This shadow can be heterogeneous due to individual accumulations of contrast agent.

Even if the above symptoms are present, it is recommended to continue the examination using CT and then DSA. These methods allow not only to confirm the diagnosis, but also to differentiate benign and malignant neoplasms, detect small tumors in the cortex, assess the condition of the renal and inferior vena cava (in particular, whether there is a tumor thrombus in them), identify tumor growth into adjacent tissues and metastases in the opposite kidney, liver, lymph nodes. All these data are extremely important for choosing treatment measures.

Radionuclide methods can play a certain role in tumor diagnostics. On a scintigram, the tumor area is defined as a zone of reduced accumulation of the radiopharmaceutical.

Bladder tumors - papillomas and cancer - are detected by cystoscopy with biopsy, but two circumstances determine the necessity and value of radiological examination. Malignant transformation of papilloma occurs primarily in the depth of the neoplasm, and it is not always possible to establish it by examining a biopsy. In addition, cystoscopy does not reveal tumor growth into adjacent tissues and metastases in regional lymph nodes.

It is advisable to begin the radiological examination of a bladder tumor with sonography or CT. On a sonogram, the tumor is quite clearly visible in a filled bladder. It is possible to judge its nature, i.e., benignity or malignancy, only if tumor invasion into the bladder wall and perivesical tissue is detected. Early stages of tumor growth are convincingly detected with endovesical sonography.

The tumor is no less clearly distinguished on computer and magnetic resonance tomograms, and the latter are especially valuable in detecting a tumor of the bottom and roof of the bladder. The advantage of MRI is the ability not only to see the lymph nodes affected by metastases, but also to distinguish them from the blood vessels of the pelvis, which is not always possible with CT. On cystograms, the tumor is visible with double contrast of the bladder. It is easy to determine the position, size, shape and condition of the tumor surface. With infiltrating growth, deformation of the bladder wall in the tumor area is established.

The main method of radiological examination of the prostate gland is transrectal sonography. Valuable information about the nature of the tumor can be obtained using color Doppler mapping. CT and MRI are important clarifying methods that allow us to judge the extent of the tumor process.

Transrectal sonography clearly shows congenital and acquired cysts of the prostate gland. Nodular hyperplasia leads to enlargement and deformation of the gland, the appearance of adenomatous nodes and cystic inclusions in it. A cancerous tumor in most cases causes a diffuse enlargement and change in the structure of the gland with the formation of hypo- and hyperechoic areas in it, as well as changes in the size, shape and structure of the seminal vesicles. Detection of any form of decreased echogenicity of the prostate gland is considered an indication for diagnostic puncture under ultrasound control.

Malignant tumors of the kidney and prostate gland are known for their tendency to metastasize to the bones of the skeleton. The former are characterized by osteolytic metastases, while prostate cancer is characterized by osteoplastic metastases, primarily to the ribs, spine, and pelvic bones. In this regard, for all malignant lesions of the urinary system and prostate gland, a radionuclide study (scintigraphy) of the skeleton is indicated, in some cases supplemented by X-ray of the suspicious bone area.

Malformations of the kidneys and urinary tract

Renal development anomalies do not always manifest with specific clinical symptoms, but they should be remembered, since these anomalies are often observed and, moreover, are not so rarely complicated by infection or stone formation. Anomalies in which tumor-like formations are palpated in the abdomen are especially dangerous. It is clear that a doctor may suspect a tumor in a case when in fact there is none.

Radiological examinations play a major role in identifying and establishing the nature of kidney and urinary tract anomalies. We will indicate the most common developmental defects and methods for detecting them. Renal aplasia is very rare, but the doctor's responsibility for its detection is extremely high. In all radiological examinations, the kidney image is absent in this case, but direct evidence of congenital absence of the kidney is only the complete absence of the renal artery on the side of the anomaly (and not its amputation at one level or another).

Somewhat more often, anomalies of size are detected - large and small kidneys. In the first case, there is a kidney with a double pelvis and two groups of calyces. There are also two ureters, but they can merge at a distance of 3-5 cm from the kidney. Occasionally, two ureters, departing from one kidney, enter the bladder with separate mouths. One of the variants of ureter doubling is its splitting in the distal section. It is more difficult to recognize a small kidney. The very fact of detecting a small kidney is not yet evidence of a congenital defect, i.e. hypoplasia, since the kidney can decrease in size as a result of nephrosclerosis. However, these two conditions can be differentiated. With hypoplasia, the kidney retains the correct shape and smooth outlines, and a calyceal-pelvic complex of the usual shape is outlined in it. The function of the hypoplastic kidney is reduced, but preserved. The second kidney is usually large in size and functions normally.

There are numerous variants of renal dystopia, i.e. anomalies of their position. The kidney can be located at the level of the lumbar vertebrae - lumbar dystopia, at the level of the sacrum and ilium - iliac dystopia, in the small pelvis - pelvic dystopia, on the opposite side - crossed dystopia. With crossed dystopia, different variants of kidney fusion are observed. Two of them - L- and S-shaped kidneys - are shown in the same figure. A dystopic kidney has a short ureter, which distinguishes it from a prolapsed kidney. In addition, it is usually rotated around the vertical axis, so its pelvis is located laterally, and the calyces are medial. Dystopic kidneys can be fused by their upper or, which is more common, lower poles. This is a horseshoe kidney.

Polycystic kidney disease is also considered an anomaly. This is a unique condition in which multiple cysts of varying sizes, not associated with the calyces and pelvis, develop in both kidneys. Large shadows of the kidneys with slightly wavy contours can be seen on plain radiographs, but a particularly vivid picture is observed with sonography and CT. When analyzing sonograms and tomograms, it is possible not only to detect kidney enlargement, but also to obtain a complete picture of the number, size and location of cysts. With sonography, they stand out as rounded echo-negative formations lying in the parenchyma and displacing the calyces and pelvis. On tomograms, cysts are seen no less clearly as clearly delineated low-density formations, sometimes with partitions and calcification. On scintigrams, with polycystic disease, large kidneys with multiple defects (“cold” foci) are visible.

The urographic picture is not at all poor. The calyces and pelvises are elongated, the necks of the calyces are lengthened, their fornical section is flask-shaped. There may be flat and semicircular depressions on the walls of the calyces and pelvises. The radiological signs of polycystic disease are even more obvious on angiograms: avascular rounded zones are noted

A large number of renal vascular anomalies are explained by the complexity of embryonic development of the kidneys. Two equivalent arterial vessels or several arteries may approach the kidney. Of practical importance is the accessory artery, which exerts pressure on the ureteral pelvis, which leads to difficulty in urine outflow and secondary expansion of the pelvis and calyces up to the formation of hydronephrosis. Urograms show a kink and narrowing of the ureter at the point where it intersects with the accessory vessel, but irrefutable evidence is obtained with renal angiography.

Radiation methods are widely used in the selection of a donor kidney and the assessment of the condition of the transplanted kidney.