Preparing the patient for pyelography. Pyelography is an informative method of X-ray examination of the kidneys. Indications and contraindications

Retrograde (ascending) pyelography (Fig. 14) is used to obtain a clear image of the upper urinary tract, pelvis and calyces, ureterography is used to obtain an image of the ureter, and pyeloureterography is used to obtain an image of the ureter. In this case, liquid and gaseous (oxygen, carbon dioxide) contrast agents are used. Air should not be applied as it may cause an air embolism. Obtaining an image of the upper urinary tract using gaseous contrast agents is called pneumopyeloureterography.

To perform retrograde pyelography, it is necessary to catheterize the ureter using a catheterization cystoscope. A liquid or gaseous contrast agent is injected through the catheter in an amount of 5-6 ml. Simultaneous bilateral catheterization of the ureters followed by bilateral pyelography is fraught with serious complications. For retrograde pyelography, the same liquid contrast agents are used as for excretory urography, only in a 20-30% concentration. The introduction of contrast solutions is carried out slowly, under pressure not higher than 40-50 mm Hg. Art.

The introduction of a contrast solution through the catheter before the onset of pain in the lower back is unacceptable; the very appearance of pain should be regarded as a complication. Colicky back pain during pyelography indicates overstretching of the pelvis and the occurrence of pelvic-renal refluxes, which are very often complicated by a purulent inflammatory process of the kidneys. To obtain a three-dimensional representation of the pelvis-calyx system, it is necessary to take pictures in various projections - in the position of the patient on the back, oblique lateral and on the stomach. When the patient is on the stomach, the lower renal calyx is very well performed. To identify the mobility of the kidneys, which is important in the diagnosis of nephroptosis, radiographs are performed in the supine and standing position.

To obtain an image of not only the pelvis, but also the ureter, pyeloureterography is used. There are two methods of pyeloureterography. The ureter is catheterized to a height of 5 cm, and then a contrast agent is injected. Such a study must be carried out on a special urological table. More often, however, the ureter is catheterized to a height of 20 cm, 5-6 ml of a contrast agent is injected through the catheter, and then the catheter is slowly removed, while continuing to inject another 2 ml of contrast fluid. After removing the catheter, an x-ray is taken. This technique allows you to get an image not only of the pelvis, but also of the ureter along its entire length, which is especially important for anomalies of the upper urinary tract and various cicatricial narrowing of the ureter.

Also noteworthy is the Klamy method, in which a contrast agent is mixed with a 3% solution of hydrogen peroxide and injected through a catheter into the upper urinary tract. The formation of gas and, accordingly, its shadow on the radiograph in one of the cups indicates the presence of an inflammatory destructive process or blood in it, which is more often observed with tumors and the so-called forical bleeding.

Pneumopyeloureterography is used to diagnose X-ray negative stones of the upper urinary tract. Against the background of the gas introduced into the urinary tract, stones become visible that are not detected on the survey x-ray. To perform pneumopyeloureterography, 8-10 ml of oxygen or carbon dioxide is injected through the ureteral catheter. Antegrade pyelography is also used, which can be performed by puncturing the renal pelvis from the lumbar side, followed by the introduction of a contrast solution. This method is indicated when retrograde pyelography cannot be performed due to obstruction of the ureter, and excretory urography does not allow one to judge the pathological process in the kidneys due to sharp decline its functions. Sometimes only antegrade pyelography makes it possible to establish a diagnosis (tumor of the ureter, closed tuberculous pyonephrosis, hydronephrosis, etc.). Antegrade pyelography can be performed with a renal fistula - nephrostomy (a contrast agent is injected through the renal drainage and a picture is taken). It is also used to determine the patency of the upper urinary tract, to detect pathological changes in the upper urinary tract. To identify the location and cause of urinary fistulas in the lower back, fistulography is used (see) by introducing a liquid contrast agent into the fistula.

Urography and pyelography can reveal various lesions of the kidneys and upper urinary tract. An increase in the size of one of the poles of the kidneys with a simultaneous change in the pattern of the pelvis-calyx system in the form of a filling defect or displacement of the calyx along the vertical or horizontal axis indicates the presence of a tumor or cyst of the kidney (Fig. 15). Enlargement of the pelvis with the expansion of the calyces indicates hydronephrotic transformation (Fig. 16). Pyelography and especially pyeloureterography can also determine the cause of hydronephrosis (stone, narrowing of the ureter). Changes in the zone of the renal calyces and papillae in the form of their mushroom-like extensions most often indicate pyelonephritis. The presence of corroded contours of the papillae with the formation of additional cavities located in the renal parenchyma with narrowing of the calyces indicates the presence of a tuberculous process (Fig. 17).

Pyelography allows you to establish the nature and localization traumatic injuries kidneys. When the kidney is ruptured, the contrast agent from the pelvis penetrates into the renal parenchyma, and sometimes beyond it, more often through the zone of the calyx, in the form of uneven lines. In an acute purulent inflammatory process in the kidney (for example, carbuncle), on the pyelogram, the affected area looks like a filling defect. At the same time, due to the phenomena of perinephritis, the kidneys lose their physiological mobility. This can be established by taking pictures while the patient is breathing. With normal mobility of the kidneys, the contours of the pelvis-calyceal system are blurred on the radiograph, and with inflammatory changes in the kidneys and perirenal tissue, they are distinct. An acute inflammatory process is also evidenced by the presence of a zone of rarefaction around the shadow of the kidney, which is detected on an x-ray with edema of the perinephric tissue.

If a kidney tumor is suspected for the purpose differential diagnosis with tumors of other localizations, along with pyelography, pneumoren and presacral pneumorethroperitoneum (see), based on the introduction of gas (oxygen and carbon dioxide) into the retroperitoneal, perirenal space, are used. Pneumoren is used relatively rarely, more often pneumorethroperitoneum is used, which makes it possible to obtain an image of two kidneys at once (Fig. 18). Pneumoren is used to identify the contours of the kidneys and adrenal glands, especially if a tumor is suspected. After pararenal novocaine blockade from 350 to 500 ml of oxygen or carbon dioxide are injected into the perirenal space. Produce radiographs in various projections. With a tumor, the corresponding section of the kidney increases with a change in its contours. Quite often pneumothorax is combined with excretory urography or pyelography and tomography.

However, pneumothorax and presacral pneumorethroperitoneum do not allow differentiation of a kidney tumor from a cyst. If a cyst is suspected, especially if it large sizes, renokistography can be used. The cyst is punctured, its contents are removed, and a contrast agent solution is injected into the cyst through the needle. This method allows not only to diagnose a kidney cyst, but also to identify tumor processes that can be observed in it. On the cystogram in these cases, uneven contours with filling defects are visible. The study of punctate allows you to confirm or reject the diagnosis of a tumor in the cyst.

Almost all kidney diseases are accompanied by changes in its vascular architectonics. These changes occur early and can be detected by renal angiography, while other methods of renal x-ray examination do not allow a diagnosis. Renal angiography allows you to identify the initial form of a kidney tumor, differentiate it from a cyst, find out the cause of hydronephrosis, resolve the issue of the possibility and nature of an organ-preserving operation (kidney resection), etc. Renal angiography is of great importance in recognizing renovascular hypertension. The following types of renal angiography are used: translumbar (by puncture abdominal aorta), transfemoral (probing the aorta through femoral artery; rice. 19), selective (probing renal artery; rice. 20), operating room (puncture of the renal artery during surgery). Renal angiography allows you to get images of the renal arteries (arteriogram) and veins (venogram), shadows of the kidneys (nephrogram), urinary tract (urogram). In order to detect compression or germination of the inferior vena cava by a kidney tumor and metastases to the paracaval The lymph nodes venocavography is used, more often by puncture of the femoral veins, followed by the introduction of 25 to 50 ml of a 70% solution of a contrast agent. Direct puncture of the inferior vena cava can also be used. With compression and germination of the inferior vena cava by a tumor, its displacement, narrowing of the lumen and the development of collaterals are noted. Metastases in the paracaval lymph nodes are diagnosed by round and oval filling defects. With varicocele in order to detect violations venous outflow with a tumor of the kidney, venography is used by puncturing one of the dilated testicular veins, followed by the introduction of a radiopaque solution.

To detect changes in the dynamics of the upper urinary tract (the so-called dyskinesias), which often accompany various pathological processes in the kidneys, pyeloscopy, urokimography (Fig. 21), X-ray cinematography are used. Pyeloscopy (transmission of the pelvis-calyx system filled with a contrast agent along the ureteral catheter) allows you to observe the nature of the emptying of the upper urinary tract and identify a violation of the motor function of the pelvis and calyces. More distinct data can be obtained with kymography, and especially with X-ray cinematography, which, thanks to the use of an electron-optical converter, is increasingly used in the clinic. Pyeloscopy, urokimography and X-ray cinematography make it possible to diagnose not only organic changes in the kidneys and upper urinary tract, but also functional, i.e., the earliest manifestations of many renal diseases.

Retrograde pyelography.

Preparation of the patient for retrograde pyelography is the same as for the overview image. Since pyelography should not be performed simultaneously on both sides, then ureteral catheterization, as a rule, should be unilateral. Ureteral catheterization is performed with a special catheter. Immediately before the introduction of a contrast agent into the pelvis, it is advisable to take an overview picture to determine the level of the end of the catheter in the urinary tract. More than 5 ml of a contrast agent should not be injected into the pelvis, this amount is equal to the average capacity of the pelvis of an adult.

Judging by the data of normal pyelograms, the right renal pelvis is located at the level of the II lumbar vertebra. The left renal pelvis is located 2 cm above the right one, however, it is very common to see that both pelvises are located below the indicated level. Sometimes it is often necessary to decide whether a given x-ray picture is a norm or a pathology. In such cases, the image of another kidney, or a radiograph of this kidney in a different projection, helps. Usually, a tendency to the symmetry of the location of the pelvis and cups in one patient is determined.

Retrograde pyelography reveals mainly the morphological picture of the upper urinary tract, sometimes it makes it possible to judge the motor function of the urinary tract when several consecutive serial pyeloureterograms are made.

Cystography.

Main indications: diseases and injuries of the bladder.

There is a descending cystography (during excretory urography) and an ascending cystography.

Ascending cystography is performed by insertion into bladder rubber catheter, a contrast agent is injected with the addition of an antiseptic (furacillin).

Anomalies in the development of the urinary system.

There are anomalies in the development of position, quantity, structure, anomalies of CHLS, vascular anomalies, anomalies of the ureter, bladder.

Position anomalies:

Dystopia- an unusual position of the kidney. May be homolateral, when the kidney is located on its side, but on unusual place. Depending on the origin of the renal artery. Normally departs at the level of the LII vertebra. If at the level of LIII-IV vertebrae - lumbar dystopia. M.b. iliac, pelvic dystopia. Differentiate with nephroptosis. With dystopia, the ureter is short, does not form bends. Heterolateral ditsopia, when the kidney is located on the opposite side, its ureter passes to its side and crosses the spine, therefore it is called heterolateral, cross dystopia. There are two types:

when a kidney is fused with another kidney, their axes resemble the letter "L".

when the kidneys are fused with poles - "S" shaped kidney.

Quantity anomalies:

Doubling (full, incomplete); third accessory kidney, hypoplasia.

Doubling of the kidney- this is a frequent anomaly, m.b. two-sided and one-sided. With complete doubling, the kidney is slightly larger than normal, two PCLs are visualized, the additional one is often represented by one cup, there is an additional ureter. Cystoscopy reveals 3 orifices of the ureters.

Third accessory kidney- more often located above the main kidney. The ureter may have its own orifice or merge with the main one. This anomaly is rare.

hypoplasia can be one-sided or two-sided. Allocate simple hypoplasia, when the kidney is only reduced in size, has a miniature PCS and vascular system. The main kidney is of normal size. It is necessary to differentiate with a secondarily wrinkled kidney. The function of the hypoplastic kidney is normal. There is hypoplasia with dysplasia, i.e. violation of the development of the renal nephron, kidney function is impaired.

Structural anomalies

spongy kidney- does not function, more often a unilateral anomaly. There are small cysts in the parenchyma of the kidney, there are calculi.

Solitary cyst- in the parenchyma of the kidney, can be located subcapsularly. The humpback kidney is differentiated from the solitary cyst by ultrasound. On ES, a protrusion of the outer contour can be determined, if the cyst is far from the PCS, then there are no changes on the ES. If it is close to CHLS, then the symptom of pushing apart the cups is determined, with the “amputation” of the cups.

The main symptoms of a pelvic cyst - ultrasound does not give an answer (an enlarged pelvis or a cyst?), R - a large pelvis kidney, displacement of the pelvis in any direction, a semilunar filling defect of the pelvis, fornixes are scattered.

Polycystic- in the kidney a large number of cyst that is enlarged. M.b. asymptomatic course, when there are many complications with the clinic and changes in the urine, atrophy of the kidney parenchyma occurs. Symptoms: the kidney is enlarged in size with polycyclic contours, more often a 2-sided process. Cysts give a sharp stretching of the fornixes, the cups can cross, move apart, maybe. "amputated"

CHLS anomalies small calyx diverticulum(rare anomaly) - a rounded protrusion associated with the neck of the calyx. Dif. dz: with carbuncles, with a tuberculous cavity. Very rare intrapelvic cyst, difficult to diagnose. On CT, the contrast agent wraps around the cyst.

Ureter anomalies m.b. doubling, tripling.

Anomalies of ureteral discharge when high, behind. There is a violation of the passage of urine, which leads to hydronephrosis.

The presence of a valve mechanism, which is located in the ureteropelvic segment, is two transverse folds that disrupt the passage of urine, which leads to the occurrence of hydronephrosis. Diagnosis is based on retrograde pyelography - a catheter in the pelvis, contrast in the pelvis, the symptom of an empty ureter is determined.

Circumcavally located ureter - the ureter is located posterior to the inferior vena cava, bends around it, is squeezed, hydronephrosis develops. The diagnosis is made on the basis of retrograde pyelography and venocavagraphy.

Neuromuscular diseases, complete atony of the ureter, of enormous size, leads to hydronephrosis.

Achalasia of the ureter - the innervation of the ureter is disturbed, the absence of the Airbach plexus, the process begins from below.

Ureterocele - cystic degeneration of the mouth of the ureter.

Bladder anomalies: diverticulum of the bladder, incomplete doubling of the bladder.

Vascular anomalies: accessory arteries supply the upper or lower pole of the kidney. They squeeze the neck of the small calyx, which leads to stenosis, hydrocalicosis. This is the so-called. Falley's symptom. If a accessory artery in the lower part, it can compress the lumen of the ureter. Diagnosis: aortography.

With the development of radiology, a large number of methods for diagnosing kidney diseases have appeared. In the middle of the 20th century, science helped to introduce radiographic methods that allow you to reliably study the structure genitourinary system. Currently, there are laboratories in every city that allow such examinations to be carried out. Retrograde urography is a method of X-ray examination of the genitourinary system using a special contrast agent, which is installed through a catheter into the urethra. This substance is impervious to X-rays, so it is clearly visible in the pictures. The method of urography is widely used for diagnosing diseases of obstruction or disorders of the genitourinary system. Retrograde urography has a reduced risk of developing allergic reactions due to the non-penetration of the contrast composition into the blood, unlike other types of medical examinations.

Advantages of the method

A number of advantages of retrograde urography should be highlighted, which significantly distinguish this technique from other types of examination of the urinary system. Conducting urography provides the most qualitative data on the degree of damage to paired organs and with the help of images you can get reliable information about the kidney parenchyma, salt formations and renal pelvis, the foci of inflammation are clearly visible in the images. The method is indispensable in identifying renal pathologies and convenient for determining the extent of the disease. The procedure does not cause inconvenience to the patient and does not cause pain, and there is no injury to the tissues of the urinary system. The method is widely used for adults and children, and has no dangerous side effects. Preparation for the procedure does not involve the reception of expensive funds. There is no danger of exposure during urography, due to the minimum doses used. The method is the most informative and gives the most reliable data.

Indications for carrying out

Retrograde urography is prescribed according to the doctor's indications to identify:

hydronephrosis

salt stones in the kidneys;
pyelonephritis;
arterial hypertension;
malignant or benign neoplasms;
kidney tuberculosis;
causes of hematuria;
congenital pathologies of the structure of the kidneys;
infectious diseases;
glomerulonephritis;
structural tissue disorders;
to monitor the state of organs in the postoperative period.

Contraindications

The appointment of the procedure is excluded for patients with the following diseases:

allergy to a contrast agent;
internal bleeding;
hemophilia;
violation of the outflow of urine;
acute renal failure;
thyrotoxicosis;
acute form of glomerulonephritis;
neoplasms of the adrenal glands.

It is strictly forbidden to conduct urography for pregnant women, in order to avoid damage to the child and the body x-rays. With extreme caution, the procedure should be carried out in patients with insulin-dependent diabetes mellitus due to the use of drugs based on metformin, which, in reaction with iodine, can lead to acidosis. These patients undergo the procedure only while maintaining the excretory function.

In the case when there are contraindications to the use of urography, the doctor prescribes other diagnostic studies, which are less informative, but differ in safety for the patient.

Patient preparation

Preparation for the procedure of retrograde urography with the introduction of a contrast agent requires certain actions. A few days before the procedure, you should refuse food products that can cause strong gas formation - cabbage, pastries, fresh vegetables, carbonated drinks. When the body appears or tends to flatulence, you need to take several tablets activated carbon. Before urography in without fail you should take an allergy test of the contrast composition: Visipak, Urografin and Cardiotrast. In case of previous allergic reactions to the drugs used, it is necessary to inform the doctor about it. 12 hours before the study, you should eat, during the day you need to limit fluid intake, but on the day of the urography in the morning you can not eat. Before the procedure, the patient must remove metal products and empty the bladder, and to relieve stress, it is recommended to take sedatives before the procedure.

Process

Urography is performed in a special x-ray room. Before the procedure, a contrast composition is selected that does not cause allergies in the patient and is not toxic.

During urography, a substance containing iodine is used. The tolerance of the patient to the substance used is established in advance. For these purposes, special tests are carried out. A scratch is made on the skin and a drop of iodine is applied to the wound. After 20 minutes, the patient is examined for the presence of a reaction in the form of a rash, hyperemia or itching. In the absence of a reaction, urography is allowed.

The procedure involves compliance with strict sterility to prevent infection of the urethra. The patient is in the supine position. Further, with the help of a catheter, the renal pelvis is emptied from the urine and a contrast composition is introduced through the urethra, which fills the ureter and kidney.

Enough 8 ml of the substance. The patient during urography feels heaviness in lumbar region. In the event of pain in the kidneys, the renal pelvis overflows due to too rapid intake of the substance in excess. Such violations of the technique of performing urography can lead to the occurrence of renal pelvic reflux.

Photographs are taken in the supine and standing positions. This approach allows you to fill the pelvis more volume with a contrast agent and conduct qualitative examination. It is recommended to take repeated pictures one hour after the installation of the substance for an adequate assessment of the excretory function of the genitourinary system.

Sometimes this method of diagnosing diseases is called retrograde ureteropyelography for a more complete interpretation of ongoing research. The procedure is not performed in case of acute inflammatory processes of the urinary system.

Are there any negative effects

During the procedure, the patient does not experience discomfort, slight discomfort may occur during the removal of the substance. Over a short period of time side effect the drug is stopped. Before the procedure, the doctor without fail warns the patient about possible unpleasant sensations such as dizziness, nausea, burning sensation at first, bad taste and an increase in body temperature.

To remove the contrast agent after urography, you should consume more green tea, fresh fruit drinks and milk.

During manipulations, some complications may occur:

pain syndrome in the lower back;
an allergic reaction up to the occurrence of anaphylactic shock;
stretching of the renal pelvis;
pelvic-renal reflux.

In case of damage to the ureter, the contrast agent can enter the kidney tissue, which leads to an increase in temperature. Technical non-observance of sterility may lead to the occurrence infection. The introduction of a contrast agent can cause acute renal colic.

> X-ray (pyelography) of the kidneys, types of pyelography

This information cannot be used for self-treatment!
Be sure to consult with a specialist!

What is pyelography and how is it performed?

Pyelography is x-ray examination prefilled kidneys urinary tract contrast agent. With the help of pyelography, the size, shape, location of the calyxes and pelvises of the kidneys, the structure and function of the ureters are assessed.

Most often, retrograde (ascending) pyelography is performed. In this case, the contrast agent is injected through the ureter using a catheterized cystoscope. Antegrade (descending) pyelography is usually used in cases where, due to obstruction of the ureter, it is not possible to introduce contrast through it, or when the patient has contraindications for cystoscopy. In the descending version of the study, the contrast is injected directly into the pyelocaliceal system of the kidney by puncture or by installing a drain.

Liquid, gas (pneumopyelography) or both (double contrast) can be used as contrast.

Indications for pyelography

Pyelography is prescribed to confirm the diagnosis of hydronephrosis, pyelonephritis, urolithiasis or oncological disease. The images show tumors, stones, blood clots, and other obstructions to the passage of urine. The study helps surgeons plan the course of the upcoming operation.

Who sends for the study, and where can I take it?

Nephrologists, urologists, oncologists, surgeons send for pyelography. It is advisable to undergo it in a medical or diagnostic medical center, equipped with an X-ray machine and specializing in the diagnosis and treatment of pathology of the urinary organs.

Contraindications for pyelography

The study is contraindicated for hypersensitivity to contrast and during pregnancy. The retrograde method is not used in case of violation of the patency of the ureters, insufficient capacity of the bladder, hematuria (the presence of blood in the urine), and the antegrade method - in case of a violation of blood clotting.

Preparation for pyelography

Pyelography technique

During retrograde pyelography, the patient lies on a special table with knees bent and hip joints legs, the position of which is fixed with special stirrups. After preliminary anesthesia, the doctor inserts a cystoscope into the bladder, and through it to the level of the renal pelvis - a special catheter. Under X-ray control, a contrast agent is slowly injected through the catheter. When the required filling of the pyelocaliceal system is reached, radiographs are performed in the anteroposterior projection, and in some cases additionally in semi-lateral and lateral projections.

During antegrade pyelography, the patient lies on a special table with his back up. After a preliminary local anesthesia the doctor inserts a needle into the pyelocaliceal system (below the level of the XII rib) to a depth of approximately 7-8 cm and connects a flexible tube to it. Under the control of fluoroscopy, a contrast agent is injected through it. Then radiographs are performed in the posterior-anterior, anteroposterior and semi-lateral projections.

Deciphering the results of pyelography

Normally, the passage of the contrast agent through the catheters occurs without difficulty, the cups and pelvises of the kidneys fill quickly, have even, clear contours and normal sizes. The mobility of the kidneys (assessed during inhalation and exhalation) should not be more than 2 cm.

Incomplete filling of the upper urinary tract with contrast, dilatation, and delayed emptying after catheter removal indicate the presence of a tumor, stone, or other obstruction. Impaired mobility of the kidneys may indicate pyelonephritis, paranephritis, tumor or abscess of the kidney. With hydronephrosis, the pyelocaliceal system of the kidneys expands.

The results of the study (images and the conclusion of the radiologist) should be shown to the doctor who sent for pyelography.

Conducting intravenous urography

After the injection of a contrast agent, images are taken at various time intervals. To obtain a picture in the nephrophase, it is recommended to take a picture immediately after the injection of a contrast agent ("at the end of the needle"). But more often in adults, the first picture is taken after 5 - 7 - 10 minutes, since the nephrophase is well expressed in the first pictures.

The second shot is in 10 - 15 - 20 minutes. It is believed that normally the greatest intensity of the shadow occurs after 12 - 15 minutes. Usually, after the second shot, you can already guess which pathological changes in the kidney, and further tactics, further pictures depend on it.

The third shot - after 30 - 40 minutes (if necessary). In the picture after 20 - 30 minutes, the bladder is usually clearly visible. At the end of the entire series, the picture - vertical shot(to exclude nephroptosis) and an orthostatic test.

This study usually ends, but sometimes it becomes necessary in delayed shots. They can be performed 1, 2, 3 or more hours after intravenous administration contrast agent. The fact is that with poor kidney function, the contrast agent is released slowly and the full picture of CHLS is detected late.

Infusion urography- modification of intravenous urography. If kidney function is reduced (see Zimnitsky's test and others functional tests), then sometimes you have to do infusion urography.

This method is used in cases where intravenous urography does not provide a clear detailed image of the cups and pelvis, so there is not enough diagnostic information (especially in initial stages tuberculosis and chronic pyelonephritis in patients with poor concentrating ability of the kidneys).

Retrograde pyelography- more difficult, instrumental method. For its implementation, special tools and a specialist urologist are required. An instrument called a cystoscope is inserted into the bladder. With its help, a special ureteral catheter is inserted into the ureter, and through it a contrast agent is introduced to the desired level (up to the pelvis) in a small amount- 7 - 8, 5 - 6 ml. Rough and rapid introduction of a contrast agent into the pelvis in large quantities leads to sharp increase intrapelvic pressure, overstretching of the PCS and the occurrence of pyelorenal reflux, the contents of the pelvis enter the blood stream, extravasation occurs in the kidney and an attack may occur acute pyelonephritis. Sometimes there are refluxes with intravenous urography.

With intravenous urography, the contrast agent is excreted by the kidneys at a concentration of 5%, and with retrograde pyelography, it is injected directly into the urinary tract at a high concentration (60-30%), so the image of the PCS is clearer and it is possible to identify already initial, small changes in the fornic apparatus of the cups. Therefore, retrograde pyelography is used when anatomical changes are not clearly identified with the help of intravenous urography. Kidney function cannot be detected using this method. In children, retrograde pyelography is rarely used, since special children's instruments are needed, the procedure is unpleasant, painful, and it is difficult for boys to perform it. In adults, this method is used quite often. Limitation of use is associated with the need for catheterization and the risk of infection.

Contraindications for retrograde pyelography - acute inflammatory processes in the kidneys and urinary tract and gross hematuria.