The urinary system in the human body is represented by the kidneys, urethra, ureter and bladder. This organ system is responsible for the formation, accumulation and elimination of urine in the human body.
Diagnosing diseases of the urinary system has certain features and difficulties, because, firstly, a large number of organs and tissues are in a small confined space, and secondly, the symptoms of urinary organs pathologies and diseases may coincide with the manifestations of disturbances in the work of other organs. Exact and informative methods of examination of these organs is something that modern medicine cannot do without. Among such methods - contrast radiography or excretory urography of the urinary organs.
How the human urinary system works and how it works
The main functions that the urinary organs perform are maintaining the water-salt balance, excretion of metabolic products, as well as participation in hormonal processes in the human body due to the development of certain types of hormones by the adrenal glands.
The kidneys are a paired organ, shaped like beans. They are located in the lumbar region. Through the renal gates, which are located on the inner side of the organ, the inferior vena cava and the aorta enter the kidney. In the same place the ureters exit from them. The sheath of the kidneys consists of fat 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 detoxification process 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 size of the human body.
The walls of the ureter consist of three layers - the internal mucous, middle muscular and external connective tissue.
The bladder is a hollow, bag-like organ that accumulates urine until it is removed from the body. The capacity of the bubble is about 300-400 milliliters. With the accumulation of fluid volume of 200 milliliters, a person feels the urge to urinate.
Anatomically, the tip, neck, body and bottom are distinguished in the organ. Its walls have a three-layer structure, consisting of:
- serous membrane, which is located outside;
- the middle layer consisting of muscles;
- inner layer: the bladder is lined inside by a mucous membrane of the transitional epithelium.
In addition, glandular epithelium and lymphatic follicles are present in the bladder. At the bottom of the bubble there is a constriction - the sphincter.
From the bladder enters the urethra having the shape of a tube, supplying urine to the urethra, through which urine is excreted from the body.
What diseases can affect the urinary system and what is the purpose of excretory urography
All components of this system are subject to several types of pathological processes:
Infectious diseases mainly affect the kidneys. The disease can overtake the other organs, but this happens less frequently, and such diseases are usually less dangerous for humans, although they certainly cause considerable discomfort, pain, burning, cramps.
Congenital abnormalities that have a genetic nature are usually manifested as anomalies of the structure, due to which urinary excretion becomes difficult or disturbed. 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 since birth, in very rare cases a person is born without kidneys (usually, babies with this pathology die immediately after birth) .
Tumor diseases of benign and malignant nature are determined in the kidneys, canals, bladder. Most often, physicians detect adenomas, angiomyolipomas, and also cancerous tumors.
A x-ray of the urinary system is assigned so that the doctor can assess the location, shape, size, as well as the excretory function and urodynamics.
What is an x-ray of the urinary organs?
The method of examination is based on the filtration ability of the kidneys, on the functions of excretion of metabolites and the excretion of processed substances. Classic X-ray images cannot display some features of the state and structure of the urinary system organs, therefore, a special contrast agent is administered to the patient in order to be able to study them. These drugs are filtered in the renal corpuscles, and in the image are displayed as areas of darkening with clear contours. A number of requirements are put forward to their properties, without which the effectiveness of the research can be reduced. Contrast substances should not accumulate in tissues or metabolize in the body.
They should have low nephrotoxicity and a normal level of x-ray contrast.
Contrasting substances can be:
The first category includes high-osmolar monomers and low-osmolar dimers: Urografin, Izopack, Yodamide, Trazograf, Telebriks, Hexabriks. Non-ionic drugs are represented by low-osmolar monomers and iso-osmolar dimers. Among these drugs - Lopamiro, Vizipak, 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-ray.
Indications and contraindications to the procedure
When is radiography of the urinary system necessary? The doctor gives the patient an appointment for diagnosis in the following cases:
- availability of results of previous examinations indicating the possible presence of cysts and tumors of any nature;
- persistent or periodic pain in the groin and lower back;
- detection of pathologies of the urinary system (diverticula, 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;
- urinary disorders;
- swelling of the face or lower limbs;
- transferred operations on the urinary organs.
Considering that during excretory urography a contrast agent is injected into the patient, 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;
- kidney tuberculosis;
- acute inflammatory processes in the urinary organs;
- hyperfunction of the thyroid gland, the presence of nodules and tumors in it;
- tumors in the adrenal glands;
- any form of renal failure, glomerulonephritis;
- acute liver failure and liver cirrhosis;
- heart attack and stroke.
Requirements for the preparation for the procedure of excretory urography
Preparatory activities are not carried out only in one case - if urgent diagnostics are necessary for a patient’s life in order to save his health and life. However, the results obtained in this way cannot be considered completely accurate and objective, since fecal masses or gas accumulations in the intestine distort the image in the photographs.
If possible, the patient needs to give up food with a high content of coarse dietary fiber a day before the scheduled examination date. Black bread, pastry baking, 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 means of reducing the formation of gas in the intestines, such as activated carbon or silicon dioxide.
In the evening before the procedure, it is recommended to do a cleansing enema, or take laxatives to empty the bowels. The study is carried out on an empty stomach, so it is impossible to eat and drink for 3-4 hours before it starts.
Preparatory procedures can improve the quality of the resulting radiographs, reduce gas formation, and reduce the likelihood of complications from the injected contrast.
How is the x-ray of the urinary system
The contrasting drug is administered intravenously to the patient. The dosage is determined on the basis of “1 milliliter of solution per 1 kilogram of body weight”. The concentration of the coloring drug in the solution is from 65 to 75%. The approximate time of contrast in the urinary organs - 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 in about 20-30 minutes. When the distribution of the solution is delayed, the last picture is taken after 40 minutes.
Usually, the patient is in a supine position during the scanning process, however, if there is a suspicion of a kidney prolapse, the pictures are taken and standing so that the doctor can assess the degree of organ displacement.
The procedure is painless, except for the very introduction of a contrast agent, and usually lasts no more than 30-40 minutes.
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 delivery of the drug by infusion - using a dropper and in a diluted form. The substance is diluted with glucose solution, in which case its dosage is doubled.
The procedure does not require the patient to stay in the hospital. The contrasting drug is eliminated from the body through the kidneys, on average, during the day. To speed up this process, the patient is recommended to drink plenty of liquids after urography.
Possible complications and risks of examination
After excretory urography, postinjection hematomas, suppurations at the injection site may appear. In rare cases, thrombophlebitis develops - inflammation of the venous wall at the site of its integrity. Such consequences are possible if the nurse did not accurately administer 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 an insignificant, but still an irradiation dose. Allergic reactions are the most dangerous of the possible complications. Anaphylactic shock or angioedema, which they can cause, in some cases causes the patient to die. Therefore, doctors before the procedure is administered to the subject a small amount of the drug intravenously to track the reaction of his body. In some cases, the doctor, still at the stage of issuing a referral for such an examination, requires the patient to undergo appropriate tests in order to determine the presence or absence of allergies. In the office where the procedure is carried out, antihistamines have been prepared for the doctors. If the patient after the introduction of contrast, there are characteristic allergic manifestations, the procedure is immediately interrupted, and the subject is provided with emergency medical care.
A certain level of danger of X-ray exposure caused her to have a large list of contraindications. In fact, the dose of radiation received is too small to harm a person. However, for example, if you carry it out more often than 1-2 times a year, there is a risk of some increase in carcinogenic danger to the body. For this reason, children and pregnant women are generally not recommended procedures in which x-ray irradiation is performed.
For the first time, an excretory urography was performed in the 1920s. Despite the fact that it was invented almost a century ago, this was not particularly affected by the popularity of the procedure in the medical world. Urologists, oncologists, gynecologists, andrologists, and general practitioners direct patients to the x-ray of the urinary system with a contrasting substance. The diagnostic results make it possible to assess the general condition of the urinary organs, the peculiarities of their structure, the presence of pathologies, diseases, and degenerative processes in them.