Retrograde pyelography. Kidney diagnostics - the best way

Pyelography is an informative method for x-ray examination of the kidneys, in particular the collecting apparatus, by introducing a liquid x-ray contrast agent into the cavity of the pelvis. The procedure is often performed in conjunction with urography, an X-ray examination of the ureters. Both studies make it possible to identify changes in the shape, position, size of the pelvis, as well as the presence of pathological processes, even minor changes in the contour of the pelvis, calyces, and renal papillae.

Kidney pyelography

It is more correct to call the study pyeloureterography, since imaging of both the pelvis and ureters is often required. A type of pyelography is considered pneumopyelography, which uses gas (carbon dioxide or oxygen, but not air). X-ray using gas allows you to determine the presence of radio-negative stones, kidney tuberculosis, tumors and bleeding in the fornix area (fornical bleeding, localized in the vaults of the small calyces of the kidneys). The double contrast method is also used - double pyelography, with the simultaneous use of gas and liquid contrast agent.

There are three types of pyelography, depending on the method of administration of the contrast agent:

1. Retrograde (ascending).
2. Antegrade (percutaneous or transdrainage).
3. Intravenous ().

Pyelography can be combined with surgical intervention (intraoperative). There are a number of contraindications for the procedure, mainly related to the method of administering the radiocontrast agent.

A general contraindication for all types of pyelography is individual intolerance to iodine preparations or hypersensitivity to other components of the administered substance.

The most commonly used substances used are:

• sodium amidotrizoate;
• iodamide;
• iohexol;
• Novatrizoate;
• sodium iopodate;
• trazograf;
• iopromide

If there is no history of data on the tolerability of iodine preparations, a test administration of the preparations in a volume of no more than 1 ml is necessary. Side effects are possible (feelings of heat, dizziness, nausea), which patients should be warned about.

Indications for use

The main indication for pyelography is the examination of urine-forming structures (calyces) and the urinary canal (pelvis, ureters). Intravenous pyelography allows one to judge the excretory capacity of the kidneys. The substance is injected directly into the bloodstream, and radiography is taken during the formation of urine (i.e., the drug enters the primary and secondary urine, into the calyces, pelvis and ureter, respectively).

Pyelography, depending on the chosen method of drug administration, allows you to identify:

1. Enlargement of the renal pelvis.
2. Obstruction of the ureters by stones or thrombus.
3. The presence of tumors in the cavity of the ureter, calyces, pelvis.
4. Diagnosis of hydronephrosis.
5. Narrowing of the ureter.

Used as an auxiliary procedure for catheterization and placement of a ureteral stent.

Kinds

For each type of pyelography, there are a number of indications and contraindications. The method of administering the contrast agent is determined by the doctor based on the general condition of the patient, the expected diagnosis and the collected medical history.

Retrograde

Retrograde pyelography is a method of introducing a radiopaque contrast agent through the urethra using a long catheterization cystoscope. In modern diagnostics, the same drugs are often used as for intravenous pyelography, but in higher concentrations, diluted in glucose.

With retrograde pyelography, the image is sharply contrasted due to the use of high concentration solutions. This makes it possible to identify the smallest changes in the renal pelvis pattern.

Kidney stones detected by retrograde pyelography

Preparation

Preparation for the procedure is minimal. It is recommended to exclude gas-forming foods from the diet a few days before the test, and perform a cleansing enema the day before. This is necessary so that the intestinal contents do not interfere with image acquisition. As a rule, the procedure is performed in the morning, so it is not recommended to have breakfast. You should also limit your fluid intake.

Performance

A radiopaque substance is injected into the cavity of the pelvis under a pressure of no higher than 50 mmHg. The volume of the pelvis is 5-6 ml, so introducing a larger volume of the substance is unacceptable. This can lead to distension of the pelvis and cause an acute attack of renal colic.

The patient should not experience pain in the lumbar region during or after administration. This indicates a complication of the procedure and the development of renal pelvic reflux (backflow of contents into the renal cavity).

X-rays must be done in several projections:

• standing;
• lying on your back;
• lying on your side;
• lying on your stomach.

Antegrade

In most cases, antegrade pyelography is used when retrograde administration of a radiocontrast agent is not possible. It is carried out by introducing contrast into the cavity of the pelvis through nephrostomy drainage or percutaneous puncture.

Indications for antegrade pyelography:

1. Obstruction of the ureters by cysts, thrombus, stones, tumor.
2. Severe hydronephrosis.
3. Assessment of the reserve capacity of the kidney.
4. Nephroptosis.
5. Pyelonephritis.

Preparation

Antegrade pyelography requires more careful preparation than retrograde pyelography. In addition, after the procedure, it is possible to install a nephrostomy tube and complex antibacterial therapy.

Performance

The patient should be positioned on his stomach. An initial survey radiography is performed. Based on the image taken, the doctor inserts a long needle into the cavity of the renal calyx or pelvis, which is accompanied by continuous injection of anesthetic.

Part of the urine is excreted, a radiopaque contrast agent is injected, and radiography is performed. After this, the entire contents of the pelvis are removed using a syringe, and an antibacterial drug is injected into the cavity. It is unacceptable to perform percutaneous puncture if the patient has blood clotting pathologies.

Inserting a needle into the cavity of the renal pelvis

Intravenous

With excretory pyelography (urography), contrast is used for a long time, which allows you to take the required number of images. This is an invasive examination in which a contrast agent is injected into the bloodstream through a vein. Allows you to determine the condition of all parts of the urinary tract.

It is used when it is impossible to perform antegrade or retrograde pyelography, as well as for a number of other reasons:

• Detection of anomalies and .
• To diagnose functional changes in the urinary tract and bladder.
• Determination of the degree and intensity of urolithiasis.
• With nephroptosis (prolapse of the kidney).
• Indirect examination of the structure of the kidney, collecting apparatus, ureters.
• Diagnosis of glomerulonephritis.

Preparation

If the patient has a history of allergies to iodine preparations, antihistamine treatment is prescribed 3-4 days before the procedure. Preparing the patient for the procedure involves administering a dose of prednisolone to avoid anaphylactic shock. As with other types of pyelography, the patient must follow a diet for 2-3 days before the procedure to prevent increased gas formation. It is recommended to have an enema the day before or in the morning of the day, and to abstain from eating.

Performance

The contrast agent, namely its amount, depends on the patient’s body weight, but should not be less than 40 ml for adults.

The most commonly used drugs are:

• Iodamide (60-76%);
• Triombrast;
• Urografin;
• Verografin.

With normal renal excretory function, the procedure takes half an hour from the moment the drug is administered. In case of insufficiency or during subsequent pharmacourography (determining the excretory capacity of the kidneys), furosemide diluted in an isotonic solution is administered intravenously.

The study is carried out in a horizontal and vertical position, which makes it possible to determine nephroptosis and various architectural changes at different angles and in different planes. Before administering the main amount of radiopaque contrast agent, it is necessary to conduct a sensitivity test: 1 ml of the drug is injected intravenously.

The patient's condition is assessed 5 minutes after administration - if there is no allergic reaction, then the examination is continued.

Contraindications

The existence of several types of the procedure makes it possible to conduct examinations in almost any condition of the patient, choosing the appropriate method of administering the contrast agent. General contraindications include:

• State of pregnancy.
• Sepsis (blood poisoning).
• Acute and chronic renal failure (mainly for excretory pyelography).
• Individual intolerance to iodine-containing drugs.
• Hyperthyroidism and thyrotoxicosis (pathologies of the thyroid gland).
• Decompensated diseases of the cardiovascular system.
• Severe form of hypertension.
• Bleeding disorders (mainly for the antegrade form).
• Inflammatory diseases of the lower urinary tract - the urethra or bladder (for the retrograde form of conduction).

To establish an accurate diagnosis, patients with suspected dysfunction of the urinary system undergo urography. This method allows you to determine functional disorders, the presence of stones, as well as the condition of the kidneys, ureters and bladder. Retrograde urography is a type of x-ray examination that makes it possible to assess the condition of the urinary system. The diagnostic result is recorded on the images, but its implementation requires appropriate preparation of the patient, and the images are prepared in a specially equipped room under the strict supervision of a doctor.

What is this method

Urography or pyelography is the filling of the pelvis and ureter with contrast, followed by taking pictures using X-rays. It can be retrograde (ascending) and antegrade (descending). The latter is performed when it is impossible to administer contrast through the ureter. Then it is introduced directly into the pelvis using a puncture. The main contraindication for such manipulation is a blood clotting disorder.

The essence of the retrograde procedure is to administer a contrast agent using a catheter into the urethra. Catheterization is carried out using a cystoscope and only on one side, since a double-sided catheter causes spasms of the pelvis and calyces in the patient. Contrast fills the ureter and renal pelvis. The temperature of the dye solution for administration should be 36–37 C, so as not to cause pain in the patient, and it should be administered very slowly.

The contrast agent is not visible through X-rays, so it makes it possible to trace the contours of the urinary organs, their patency and functioning.

The disadvantage of the method is that the study can only be carried out on the side where the kidney works. The positive thing is that the diagnosis does not result in allergies, since the contrast does not enter the bloodstream.

When is urography performed?

The technique is performed on patients to identify the following conditions:

• developmental defects of the urinary organs;
• chronic inflammation;
• neoplasms;
• ICD (stones);
• injuries;
• blockage of the ureter.

The study helps to see the pathological mobility of the kidneys, and is also necessary during preparation for surgery and in the postoperative period.

Impossibility of carrying out the technique

The procedure cannot be performed on patients with the following characteristics and pathologies:

• allergy to contrast;
• internal bleeding of unknown etiology;
• decreased blood clotting;
• impaired excretory ability of the kidneys;
• renal failure;
• acute glomerulonephritis;
• thyrotoxicosis;
• adrenal neoplasm.

Diagnosis is prohibited for women during pregnancy, since X-rays negatively affect not only the female body, but also the development of the fetus. The procedure should be carried out with caution in patients with hormonal disorders (diabetes mellitus) who are taking medications based on metformin, since in combination with iodine the drug leads the patient to severe acidosis. Such patients undergo the procedure only if the excretory function of the kidneys is preserved.

If the patient has contraindications to the procedure, the doctor replaces the diagnostic study with a less informative one, but safer for such a patient. This may be a CT, MRI or ultrasound of the kidneys.

Preparation rules

In order for the pictures to be clear, the patient must be prepared for the manipulation. Preparation involves cleansing the intestines of feces and gases. To do this, exclude foods that provoke flatulence from the patient’s diet:

• raw vegetables and fruits;
• legumes;
• mushrooms;
• cabbage;
• black bread;
• dairy products;
• carbonated drinks.

The patient must adhere to this diet for three days. To maximize bowel cleansing, the patient takes a laxative and sorbex or activated charcoal. Its dosage is determined by the doctor. The patient must undergo a cleansing enema in the evening, before the procedure and 3 hours before it is performed.

If patients are bedridden or weakened, they are recommended to move more to improve intestinal motility and relieve gases.

The procedure is carried out on an empty stomach or after a light breakfast (unsweetened tea and a sandwich). If the patient experiences increased emotional arousal before the procedure, he is given a sedative.

How is the examination carried out?

The manipulation is carried out in an equipped X-ray room. Before starting the procedure, a contrast agent is selected. It should not cause allergic reactions and meets the following criteria:

• non-toxic;
• does not accumulate in tissues;
• participates in metabolic processes.

To perform retrograde urography, contrast containing iodine is used. Before starting the procedure, the patient’s tolerance to the substance must be established. To do this, a test is carried out the day before. Make a small scratch on the skin and apply a few drops of iodine to it. After 15–20 minutes, see if there is an unnecessary reaction in the form of hyperemia, rash, itching, or swelling. If there is no reaction, then diagnostics can be performed.

The procedure is carried out while maintaining sterility so as not to cause urinary tract infection. The patient is in a supine position. First, a catheter is used to empty the pelvis and ureter of urine, and then a contrast agent is injected through it, filling the renal pelvis and ureter.

Usually 5–8 ml of contrast is sufficient. The patient should feel a slight heaviness in the lumbar region. The appearance of pain in the area of ​​the kidneys indicates overstretching of the renal pelvis, which occurs with the rapid administration of a contrast agent or a large amount of it. This condition can cause pelvic-renal reflux.

Pictures are taken with the patient lying on his back, stomach, side and standing. This makes it possible to completely fill the pelvis with contrast and conduct an objective study. It is recommended to repeat the image an hour after administration of the substance to assess the excretory function of the kidneys and ureters.

Experts also call this diagnostic method retrograde ureteropyelography. This interpretation gives an idea of ​​the scope of the research being carried out. Diagnosis is not performed for acute inflammation of the upper and lower parts of the urinary system.

Complications

During the diagnostic study, the following undesirable manifestations may develop:

• renal pelvic reflux;
• distension of the pelvis;
• lower back pain;
• allergies up to the development of anaphylactic shock.

Diagnosis is often complicated by the appearance of hematomas and blood clots at the puncture site. If the ureter is damaged, contrast may enter beyond it or into the kidney tissue, which subsequently causes an increase in body temperature. If sterility is not maintained, infectious infection often occurs, and the administration of contrast can provoke the development of renal colic.

Conclusion

The technique performed is informative and, with proper preparation, and if there are no contraindications, helps to establish a diagnosis and carry out appropriate treatment.

At the initial stage of diagnosis, many patients are prescribed a survey radiograph of the paired organ and ureteric canals. But this technique only makes it possible to evaluate their location and structure, without giving a specific answer about their functional capabilities. This method of examination helps doctors plan upcoming surgical interventions.

Pyelography is an examination method that can be used to obtain an image of an organ and canals. Often, pyelography is performed when the bladder is examined with an endoscope. In this case, the contrast component is administered using a catheter.

Since methods and technologies have improved, today they are increasingly using other methods of examination - and ultrasound.

How is pyelography performed?

It is more correct to call such a study pyeloureterography, because quite often it is necessary to obtain images of the pelvis and ureteric passages. One of the types of pyelography is pneumopyelography, performed using oxygen or carbon dioxide.

This method makes it possible to identify the presence of negative lesions, new formations and bleeding. In addition, a double contrast technique is used - gas and liquid contrast are used simultaneously.

Today, pyelography is performed in three ways.

Retrograde

In this method, the drug is administered through the ureter using a long cystoscope with a catheter. Today, the same drugs that are administered intravenously are often used, but in higher concentrations, diluted with glucose.

With this research method, the image is contrasted because a highly concentrated composition is used. But it is possible to examine the smallest changes in the kidneys and...

Intravenous

Before performing it, it is necessary to test the kidneys for their functionality. Most likely, you will have to take laxatives or give enemas to cleanse the stomach.

A needle is inserted into a vein, through which a contrast liquid with a medicinal composition is injected. Over the next thirty to sixty minutes, the patient will have to lie on a special table while X-rays are taken. You may need to hold your breath at your doctor's command.

Using a contrast component, the ureteral system will be highlighted. Using this image, a specialist will be able to examine all organs and determine the problem. The procedure ends with emptying the bladder.

Ureteropyelography

With its help, images of the upper ureteric passages are obtained. At the same time, using catheterization to introduce the contrast component. The study uses an iodine-containing composition. It is absorbed in a certain amount into the mucous membrane of the ureteral canal, entering the blood, but is still used for patients with a high level of sensitivity who cannot tolerate the introduction of contrast into a vein.

Note that ureteropyelography is performed in case of uninformative images or their low quality, in case of kidney failure. The main goal of the method is to assess the anatomical structure and condition of the upper ureteric passages.

Indications for the procedure

It is prescribed for patients in whom a blockage of the ureteral canals is suspected by a neoplasm, calculus, blood clot, or narrowing of the passage.

Pyelography will help evaluate the lower sections of the canals, to which the flow of urine may be difficult. In addition, this method is used to determine the normal location of the catheter or.

The advantage is that the examination can be carried out even if the patient has obvious allergic signs to the contrast agent or impaired kidney function.

Contraindications

There are some factors that can affect the result of the study:

• gas formation in the intestinal tract;
• the presence of barium in the gastrointestinal tract from a previous x-ray.

Preparing for pyelography

The specialist will explain the essence of the process and answer all your questions. You will be asked to sign an agreement form, with which you will confirm your consent to this type of research. It is recommended that you carefully study such a document, clarifying obscure points.

You will have to give up food for a certain time, which the doctor will tell you about. By the way, it will not be superfluous if you tell your doctor what medications you are taking today.

If you experience frequent bleeding or use medications that reduce blood clotting, you should also tell your doctor about this. You'll probably have to take a break from this for a while.

If there are some peculiarities in the body or certain diseases, the doctor prescribes preparatory measures taking them into account.

Methodology

The procedure can be performed on an outpatient basis or in a hospital setting. Typically, the study goes like this:

Decoding the results

Under normal conditions, contrast fluid moves easily through the catheter, filling cups and pelvises that have smooth contours and correct dimensions. During breathing, the mobility of the paired organ should not exceed two centimeters.

Incomplete filling of the upper zones of the ureteric passage with contrast, expansion or delayed emptying after the catheter is removed may indicate existing tumors, stones and other obstacles. Deviations in the mobility of the paired organ indicate that pyelonephritis is developing, an abscess has appeared, and is growing. If diagnosed, then expansion is observed.

The results obtained after the examination must be passed on to the attending physician.

Advantage of pyelography

To obtain good quality images, a retrograde examination is performed with the injection of contrast fluid through the ureteral meatus. Using this method, new formations and injuries to the channels for urine output are diagnosed.

In addition, the procedure makes it possible to examine almost all ureteric passages in one session. This allows you to reduce the examination time and reduce the amount of contrast element that is introduced into the human body. As a result, the load on the paired organ is reduced, and the number of adverse reactions associated with allergenic manifestations is reduced.

Complications

Complications may arise due to the radiation exposure the body receives during procedures. Many experts recommend keeping records of such procedures, recording the radiation exposure.

If a woman is pregnant or there is a suspicion of such a condition, then pyelography is not prescribed. The fact is that radiation can cause abnormal development of the fetus.

When contrast is used, the risk of an allergic reaction increases. The patient, who knows his problems, should notify the doctor about this.

People suffering from kidney failure are required to notify a specialist about this. The fact is that the contrast agent can worsen the situation. Pyelography is contraindicated in case of dehydration.

After the procedure, the patient may experience sepsis, infection in the ureter, perforation of the ureter, bleeding, nausea and even vomiting.

After pyelography

You will be monitored by medical staff for some time after this examination. You measure the pressure in the arteries, pulse, breathing. If all of the above indicators are within normal limits, you will be sent to the ward or sent home.

You will have to measure the volume of biological fluid that will be released during the day and monitor its shade (there is a possibility that there will be blood particles in it). A slight redness of the urine is acceptable, there is no reason to worry about it. An experienced specialist will give you the necessary recommendations that will help in your observations.

You may begin to experience pain while passing urine. At such moments, you are allowed to use painkillers prescribed by the doctor. Do not take aspirin and a number of drugs with similar effects that can increase blood flow. In this matter, it is recommended to strictly adhere to the doctor’s prescriptions.

It is imperative to go to the hospital if you start to worry about:

• fever or chills occur;
• redness, swelling, bleeding and other discharge will appear;
• a feeling of pain will begin, the level of blood in the biological fluid will increase;
• in the process of emission of urine certain difficulties are experienced.

Taking into account the characteristics of your body, the doctor will prescribe additional research.

Conclusion

It can be concluded that pyelography allows one to evaluate the structure and structural features of the ureteric canals, partially. Using this method, a large number of diseases can be diagnosed. The examination is carried out according to various modifications, which are used in cases where other methods are not suitable due to pathological abnormalities existing in the body.

At the first stages of diagnosis, most patients are prescribed a plain radiograph of the kidneys and urinary tract. However, this technique only allows one to assess their position and structure, without giving an unambiguous answer to the question of their functional ability.

Contrasting process

Therefore, one of the main studies performed in patients with kidney damage is pyelography. This procedure should be performed on the patient on an empty stomach. Preparation is carried out in the form of cleansing the intestines and bladder. Urotropic contrast agents are administered intravenously. Along the route of their introduction, modification in the form of retrograde pyelography or antegrade pyelography is possible.

The first series of pictures are taken after one or two minutes, then they wait five minutes (abdominal compression is performed if possible to retain urine in the kidneys) and a second series of pictures are taken. After this, the compression is removed and the last series of images is taken after 10-15 minutes.

This method provides images of several stages of kidney function.

Snapshot time	Phase	Description
1-2 minutes	Nephrographic	A contrast agent is imaged in the renal parenchyma, and their excretory function is assessed. A parallel CT scan can be performed for improved visualization.
4-5 minutes	Renal pelvis	The renal pelvis and ureters are clearly visualized. When the abdomen is compressed, the outflow of urine slows down, which gives more time for taking pictures and improving the quality of the images.
10-15 minutes	Bladder filling	Allows you to obtain images of the bladder and lower ureters. If necessary, you can take pictures after another hour or additionally take a tomogram, a targeted x-ray of the bladder.

Modifications of the method for severe cases

Unfortunately, a number of pathologies can disrupt the passage of the contrast agent in one of the phases, which will lead to the inability to obtain a complete picture of the urinary tract.

In such cases, retrograde pyelography is used. The contrast is injected in the reverse way, through the urethra and upward, bringing it to the pyelocaliceal system. This method is used in people with reduced excretory capacity of the kidneys, when the contrast agent lingers for a long time in the vessels and parenchyma without entering the calyces.

The essence of intravenous pyelography

There is a modification of the technique called antegrade pyelography, in which a needle or nephrostomy tube is inserted into the kidney, injecting contrast first into the calyces and pelvis. This makes it possible to conduct a study when there is a violation of the outflow of urine and a decrease in excretory function.

Optimal research methodology

However, conventional intravenous pyelography does not always accurately depict damaged structures. As the contrast passes through the urinary tract, an additional series of images can be taken, which will be called ureterography, but the images are often not clear enough, and part of the tract may be spasmed and it will not be possible to get a complete picture.

Therefore, to obtain better images, a retrograde injection of contrast agent is performed through the external opening of the urethra. This study is called retrograde ureteropyelography.

It can be used to diagnose obstructive urethral diseases:

• strictures;
• tumors;
• diverticula;
• traumatic injuries of the urinary canals.

Using pyelography, you can evaluate not only the anatomical features of the organs of the excretory system, but also their function

Advantages of the technique

In addition, retrograde ureteropyelography allows you to examine almost the entire urinary tract during one procedure, with one injection of contrast agent. Thanks to this, it is possible to reduce the procedure time and the amount of contrast administered. Therefore, the use of retrograde ureteropyelography reduces the load on the kidneys and reduces the number of adverse reactions, since, unfortunately, some patients may develop sensitivity to contrast agents.

Conclusion

Thus, pyelography makes it possible to evaluate the structure and structure of the urinary tract and, in part, the renal parenchyma, which helps to diagnose many diseases. The method has many modifications that make it possible to use it in cases where conventional methods are impossible due to pathology.

One of the most popular and most informative methods of x-ray examination of the kidneys is pyelography, which is carried out by introducing a liquid x-ray contrast agent into the renal collecting cavity. Almost always, this examination is accompanied by urography - x-ray diagnosis of the ureters. Both procedures are aimed at identifying various types of pathologies, changes in the appearance and shape of the renal pelvis itself, as well as its contour, calyces and renal papillae.

Types of pyelography

When diagnosing the renal apparatus, images of the ureters are often also required, so pyelography is performed simultaneously with urography. One of the varieties of this procedure is pneumopyelography, when oxygen or carbon dioxide is used for diagnosis. This technique allows you to diagnose the presence of bleeding or stones in the kidneys, as well as identify tumors or tuberculosis of the kidney.

Sometimes the double contrast method is used, when pyelography uses both a liquid contrast agent and a gas simultaneously.

Depending on the method of administration of the X-ray contrast agent, pyelography is divided into several types: retrograde or ascending, intravenous or excretory, as well as antegrade or percutaneous pyelography.

This study can also be used in combination with surgery. This type of pyelography is called intraoperative. There are some contraindications for this technique, depending mainly on the method of introducing the contrast agent into the body. But for all options and types of pyelography, a general contraindication is increased sensitivity or individual intolerance to other components of the radiocontrast agent.

The most commonly used contrast agents are: trazograf, iohexol, iopromide, sodium iopodate, sodium amidotrizoate, novatrizoate and iodamide.

If the degree of tolerability of a particular drug is unknown, then the contrast agent is administered in a test mode, with a volume not exceeding one milliliter. In case of hypersensitivity, the patient may experience adverse reactions such as nausea, dizziness and a feeling of heat.

Indications and contraindications for the examination

Pyelography is often prescribed to identify the presence of various pathologies in the human body:

• blockage of the ureters with blood clots or stones;
• hydronephrosis;
• various kidney injuries;
• dilation of the renal pelvis;
• narrowing of the ureters;
• tumors in the cavity of the renal pelvis, calyces and ureters.

This procedure is also used as an additional procedure when placing a catheter or ureteral stent.

There are also a number of contraindications for conducting this study. However, it is worth noting that the existence of several varieties of this procedure makes it possible to bypass a number of contraindications and conduct examinations in almost every patient. To do this, you just need to find the most appropriate way to introduce a radiocontrast agent. General contraindications for all types of pyelography are:

• hypersensitivity to drugs containing iodine;
• pregnancy period;
• vascular and heart diseases;
• chronic and acute forms of renal failure;
• blood poisoning;
• severe hypertension;
• pathologies of the thyroid gland: thyrotoxicosis and hyperthyroidism;
• bleeding disorders;
• infectious and inflammatory processes in the lower parts of the urinary tract.

Types of pyelography, preparation and implementation of the procedure

Each individual type of such research has its own characteristics, advantages and disadvantages. The method by which the contrast agent will be introduced into the patient’s body is determined by the attending physician based on the individual characteristics of the patient and the expected disease.

Pyelography happens:

• retrograde;
• antegrade;
• intravenous.

Retrograde pyelography is a type of procedure in which a contrast agent is introduced into the patient's body through the urethra using a long catheterization cytoscope. In this case, medications such as urografin, triombrast, verografin, iodamide are used.

The same drugs are often used for intravenous pyelography. However, in this particular case they are used in solution and in high concentrations.

Because of this, the image obtained with retrograde pyelography is very contrasting, which makes it possible to detect even the slightest changes in the renal pelvis pattern.

A few days before retrograde pyelography, it is recommended to exclude foods that cause increased gas formation from the diet. And immediately before the procedure itself, perform a cleansing enema. Pyelography is usually performed in the morning, so breakfast should be canceled and fluid intake should be limited.

The procedure involves injecting a radiopaque contrast agent into the cavity of the renal pelvis under pressure. The pelvis reaches a volume of five to six milliliters, so the substance should also be administered in small volumes, since distension of the pelvis can lead to an acute attack of renal colic.

Pain in the lumbar region during or after the procedure indicates a possible complication – pelvic-renal reflux. Typically, retrograde pyelography is performed in several positions: standing, as well as lying on the stomach, side or back.

Antegrade pyelography is used when it is impossible to perform retrograde injection of a contrast agent. This type of procedure is performed by injecting a radiopaque contrast agent into the renal pelvis using percutaneous puncture or nephrostomy drainage.

This procedure differs from retrograde pyelography in that it requires more thorough preparation. And after the examination, antibiotic therapy or the installation of a nephrostomy tube is often required. It is also recommended to completely abstain from food and fluid intake six to eight hours before the test and do a cleansing enema the day before the test.

During antegrade pyelography, the patient is in the prone position. First, an initial survey x-ray of the renal area is taken, on the basis of which a long needle is inserted into the cavity of the pelvis. The procedure is accompanied by the introduction of anesthesia.

Some of the urine is drained, a contrast agent is injected and pyelography is performed. At the end of the procedure, the contents of the renal pelvis are removed and an antibacterial drug is injected using a syringe. Bleeding disorders are a direct contraindication for antegrade pyelography.

Intravenous or excretory pyelography allows examination to be carried out for quite a long time. In this type of radiography, a dye is injected into the systemic bloodstream through a vein. This method of examination promotes a good view of all departments and areas of the urinary system.

Intravenous pyelography is used if for some reason it is impossible to perform a retrograde or antegrade procedure.

Preparation for such an examination requires even more careful preparation, especially in cases where the patient is allergic to iodine-containing drugs. Before carrying out the procedure in such patients, it is necessary to introduce the required dose of prednisolone into the body to eliminate the possibility of anaphylactic shock. In addition, it is also necessary to follow an appropriate diet, as with other types of procedures, perform a cleansing enema and refrain from eating and drinking before the procedure.

The contrast agent is administered intravenously, in a dosage proportional to the patient’s body weight, but not less than forty milliliters for adults. Usually the procedure takes about half an hour. If pharmacourography is also required, an isotonic solution of furosemide should also be administered.

This examination is carried out in a standing and lying position, which allows you to examine pathological changes from different angles. Before administering the main dose of radiopaque contrast agent, a sensitivity test is performed by injecting a very small dose intravenously, approximately one millimeter of the drug. If after five minutes the patient does not show any adverse allergic reactions, then a full examination is carried out.

Summing up

Pyelography is one of the types of x-ray examination that allows you to identify the presence of various types of pathologies in the urinary system. It is carried out in various ways, depending on the introduction of the contrast agent into the human body. There are a number of contraindications to such a study, so before it you need to consult a doctor and undergo some tests to eliminate possible unpleasant and negative consequences.