X-ray (intravenous excretory urography) of the urinary system

The urinary system in the human body is represented by the kidneys, ureters, bladder and urethra. This organ system is responsible for the formation, accumulation and excretion of urine in the human body.

Diagnosis of diseases of the urinary system has certain features and difficulties, since, firstly, a large number of organs and tissues are located in a small limited space, and secondly, the symptoms of pathologies and diseases of the urinary organs may coincide with manifestations of disorders in the work of other organs. Accurate and informative methods of examining these organs are something that modern medicine cannot do without. Among these techniques are contrast radiography or excretory urography of the urinary organs.

How does the human urinary system work and how does it work?

The main functions that the urinary organs perform are maintaining the water-salt balance and removing metabolic products.

The kidneys are paired organs, shaped like beans. They are located in retroperitoneal space, lumbar region. Through the renal gates, which are located on the inside of the organ, the inferior vena cava and the aorta enter the kidney. In the same place, the ureters exit from them. The shell of the kidneys consists of adipose and connective tissue, and the structural units of the organs are nephrons – a set of glomeruli and excretory tubules. Of the entire urinary system, only the kidneys are involved in the processes of detoxification of the body, the rest of its organs are responsible only for the accumulation and excretion of urine.

The ureter looks like a hollow tube with a lumen thickness of about 12 millimeters. Its length is 30-32 centimeters, although it may vary depending on the human body.

The walls of the ureter consist of three layers – internal mucous, middle muscular and external connective tissue.

The bladder is a hollow, sac-like organ that stores urine until it is excreted from the body. The bubble capacity is about 300-400 milliliters. With the accumulation of a volume of fluid from 200 milliliters, a person feels the urge to urinate.

Anatomically, the organ is divided into apex, neck, body and fundus. Its walls have a three-layer structure, consisting of:

• serous membrane, which is outside;
• the middle layer, consisting of muscles;
• inner layer: the bladder is lined from the inside with a mucous membrane of transitional epithelium.

In addition, glandular epithelium and lymphatic follicles are present in the bladder. At the bottom of the bladder there is a narrowing – the sphincter.

The urethra comes out of the bladder – urethra, having the shape of a tube through which urine is excreted from the body.

What diseases can affect the urinary system and why is excretory urography prescribed?

All components of this system are subject to several types of pathological processes:

• infectious;
• congenital;
• tumor.

Infectious diseases often affect the kidneys. The disease can also overtake other organs, but this happens less frequently, and such diseases are usually less dangerous for humans, although they certainly cause significant discomfort, pain, burning, and cramps.

Congenital abnormalities of a genetic nature usually manifest themselves as anomalies in the structure, due to which the excretion of urine is difficult or impaired. For example, the shape or size of the bladder may be disturbed, the ureter may be absent, and some people may have one kidney instead of two from birth, in very rare cases a person is born without kidneys at all (usually, babies with this pathology die immediately after birth) or, conversely, there may be a doubling of one or both kidneys.

Tumor diseases of a benign and malignant nature are determined in the kidneys, canals, bladder. Most often, adenomas, angiomyolipomas, and also cancerous tumors are found.

Violation of metabolic processes in the body can cause the formation of kidney stones.

An x-ray of the urinary system is prescribed so that the doctor can assess the location, shape, size, as well as excretory function and urodynamics.

What is a urinary tract x-ray

The examination method is based on the filtration capacity of the kidneys, on the functions of excretion of metabolites and excretion of processed substances. Classical x-rays cannot reflect some features of the state and structure of the organs of the urinary system, so the patient is injected with a special contrast agent in order to be able to study them. These drugs filtered by the kidneys, and are displayed in the picture as dark areas with clear outlines. A number of requirements are put forward for their properties, without which the effectiveness of the study may be reduced. Substances-contrasts should not accumulate in tissues or be metabolized in the body.

They should have low nephrotoxicity and a normal level of radiopacity.

Contrast agents can be:

• ionic;
• non-ionic.

The former include high-osmolar monomers and low-osmolar dimers: Urographin, Isopak, Iodamide, Trazograph, Telebrix, Hexabrix. Non-ionic drugs are represented by low-osmolar monomers and iso-osmolar dimers. Among these drugs are Lopamiro, Visipak, Omnipak, Ultravist.

The introduction of contrast, among other things, allows you to get a clear image of hollow organs, in contrast to ultrasound or classical x-rays.

Indications and contraindications for the procedure

When is a urinary tract x-ray needed? The doctor gives the patient an appointment for diagnosis in the following cases:

• the presence of the results of previous examinations indicating the possible presence of cysts and other neoplasms of any nature;
• persistent or recurrent pain in the groin and lower back;
• detection of pathologies in the development of the urinary system (diverticulum, polycystic kidney disease, doubling of the ureters);
• injury to the lumbar region;
• chronic infectious processes in the kidneys;
• the appearance of blood in the urine;
• urinary incontinence;
• violations of the urinary process;
• swelling of the face or lower extremities;
• transferred operations on the urinary organs;
• if you suspect the presence of stones in the kidneys or in the urinary tract.

Given that during excretory urography, the patient is injected with a contrast agent, and after that he is subjected to X-ray irradiation, the procedure has a specific list of contraindications:

• intolerance to iodine-containing drugs, the presence of allergies;
• tuberculosis of the kidneys;
• acute inflammatory processes in the urinary organs;
• hyperfunction of the thyroid gland, the presence of nodules and neoplasms in it;
• neoplasms in the adrenal glands;
• any form of renal failure, glomerulonephritis;
• acute liver failure and cirrhosis of the liver;
• pregnancy;
• heart attack and stroke.

Requirements for preparation for the procedure of excretory urography

Preparatory measures are not carried out only in one case – if the patient’s life requires urgent diagnostics in order to save his health and life. However, the results obtained in this way can be considered incompletely accurate and authentically objectivebecause stools or accumulations of gas in the intestines often distort the picture.

If possible, the patient needs to refuse food with a high content of coarse dietary fiber a day before the scheduled date of the examination. Black bread, confectionery, legumes, some types of vegetables, milk and dairy products, carbonated drinks, kvass and alcohol should be excluded from the diet before urography. The doctor may prescribe an additional intake of drugs that reduce intestinal gas formation, such as activated charcoal or silicon dioxide.

In the evening before the procedure, it is recommended to do a cleansing enema, or take laxatives to empty the intestines. The study is carried out on an empty stomach, so 3-4 hours before it starts, you can not eat or drink.

Preparatory procedures improve the quality photo, reduce gas formation, and reduce the likelihood of complications from the injected contrast.

How is an X-ray of the urinary system performed?

First, a native image is taken, after which a contrast agent is injected intravenously. The dosage is determined on the basis of “1 milliliter of solution per 1 kilogram of body weight.” The concentration of the coloring agent in the solution ranges from 65 to 75%. The approximate time for the contrast to enter the urinary organs is from 5 minutes to half an hour, depending on the age of the patient. Approximately 3-5 minutes after the administration of the drug, the first picture is taken, after 7 minutes – the second, after 15 – the third, and, if necessary, another one can be taken after about 20-30 minutes. If the distribution of the solution is delayed, the last picture is taken after 40 minutes.

Usually, during the scan, the patient is in a supine position, however, if there is a suspicion of a prolapsed kidney, pictures are taken while standing so that the doctor can assess the degree of displacement of the organ.

The procedure is painless, except for the injection of a contrast agent, and usually lasts no more than 30-40 minutes.

The contrast is injected with a syringe, however, in cases of diagnosing a decrease in the concentration of endogenous creatinine, it is necessary to ensure the supply of the drug by infusion – using a dropper and in a diluted form. The substance is diluted with a solution of glucose, in which case its dosage is doubled.

The procedure does not require the patient to stay in the hospital. The contrast agent is excreted from the body through the kidneys, on average, within a day. To speed up this process, the patient is advised to drink plenty of fluids after urography.

Possible complications and risks of the examination

After excretory urography, post-injection hematomas, suppuration at the injection site may appear. In rare cases, thrombophlebitis develops – inflammation of the venous wall at the site of violation of its integrity. Such consequences are possible if the nurse did not accurately inject the drug.

The main danger posed by this diagnostic method is the use of a contrast agent that can cause allergies, as well as the need for the patient to receive, albeit insignificant, but still a dose of radiation. Allergic reactions are the most dangerous of the possible complications. Anaphylactic shock or Quincke’s edema, to which they can lead, in some cases causes the death of the patient. Therefore, before starting the procedure nurse or doctor a small amount of the drug is administered intravenously to the subject to monitor the reaction of his body. In some cases, the doctor, even at the stage of issuing a referral for such an examination, requires the patient to pass the appropriate tests in order to establish the presence or absence of contraindications for the introduction of contrast. In the room where the procedure is carried out, at the copperQing workers prepared antihistamines. If the patient has characteristic allergic manifestations after the injection of contrast, the procedure is immediately interrupted, and the subject is provided with emergency medical care.

A certain level of danger of X-ray exposure led to the presence of a large list of contraindications. In fact, the dose of radiation received is too small to harm a person. However, for example, if it is carried out more often than 1-2 times a year, there is a risk of some increase in the carcinogenic hazard to the body. For this reason, procedures in which X-ray irradiation is carried out are generally not recommended for children and pregnant women.

For the first time, excretory urography was carried out in the 20s of the last century. Despite the fact that it was invented almost a century ago, this did not particularly affect the popularity of the procedure in the medical world. Urologists, oncologists, gynecologists, andrologists, and therapists refer patients to an x-ray of the urinary system with a contrast agent. The diagnostic results make it possible to assess the general condition of the urinary organs, the features of their structure, the presence of pathologies, diseases, degenerative processes in them.