X-ray of the kidneys

, medical expert
Last reviewed: 31.05.2018

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X-ray examination of the urinary system

It is difficult to imagine a modern urological clinic without radiation studies. In fact, it is thanks to them that urology has become one of the most accurate medical disciplines. This is not surprising, since ray methods allow the doctor to study in detail both the morphology and the function of the excretory organs and detect pathological changes in them in the early stages of development.

Indications for radiation studies are very wide. They are prescribed for each patient who is suspected of damage or disease of the kidneys, ureters, bladder, prostate. The appointment is made by the attending physician.

The head of the radiation department or a specialist in the field of radiation diagnostics chooses the research methods and the sequence of their application. Qualified urologists, as a rule, are well prepared for radiation diagnosis of injuries and diseases of the kidneys and urinary tract and can contact the radiologist themselves to establish the order and volume of radiation studies themselves.

Methods of radiological examination of the urinary system

A survey radiograph of the abdominal region. Many urological patients perform a survey of the kidneys and urinary tracts at the first stage of the examination or after sonography. For this, the patient needs to be prepared - to clean the intestine the night before and the morning of the day of the study. In the X-ray room, the patient must appear on an empty stomach. The only exception is patients with acute renal colic: they have to be examined without cleansing the intestine. The patient is placed on his back and the picture is performed on a large film so that both kidneys, large lumbar muscles and pelvis are displayed on it to the level of the lone articulation.

The kidneys all over the length of the survey image are not always, approximately 60-70% of the subjects. Normally they look like two bean-like shadows, located at the level of ThXII-LII on the left and LI-LII on the right. Thus, the left kidney is slightly higher than the right kidney. The upper poles of the kidneys are normally located closer to the midline of the body than the lower ones. The outlines of the kidneys are normally clear, their shadow is uniform. The individual variant is the arcuate bulging of the outer contour (the so-called humpback kidney). Ureters on the survey radiograph of the abdominal cavity are not visible. A urinary bladder filled with urine can cause an oval or round shadow in the pelvis. The normal prostate gland in the shadows does not give. The main purpose of the survey radiography - the detection of concrements, calcifications and gas.

Intravenous urography. This is one of the main radiographic studies conducted by patients with lesions of the urinary system. Intravenous urography is based on the physiological ability of the kidneys to capture iodinated organic compounds from the blood, concentrate them and excrete them in the urine. In case of usual urography, the patient, on an empty stomach, after preliminary cleansing of the intestine and emptying the bladder, 20-60 ml of one of the urotropic contrast substances, ionic or, more preferably, neuronal ones, are intravenously administered.

 Intravenous urography 

Direct pyelography. Excretory urography in most cases provides the study of the calyx-pelvis system. However, in some patients, especially when the contrast medium is weakly excised, if it is necessary to examine the calyx and pelvis in detail, direct contrast of the upper urinary tract must be made. It is performed retrograde, through a catheter installed in the ureter (retrograde pyelography), or antegrade, through a needle or nephrostomy tube (antegrade pyelography). On the radiographs obtained, all the details of the structure of the calyx and pelvis are clearly visible, it is possible to detect insignificant changes in their contours and shape. Limited use of direct pyelography is associated with the need for catheterization of the urinary tract and the risk of their infection. This study is contraindicated in acute inflammatory processes in the kidney and urinary tract, as well as in macrohematuria.

Angiography of the kidneys. There are general and selective arteriography of the kidneys. In the first case, the catheter is guided from the femoral artery to the abdominal aorta and its end is established above the site of the renal arteries. If, due to occlusal involvement of the aorto-ileum-femoral segment, catheterization of the aorta through the femoral artery is not possible, recourse is made to transluminal puncture of the aorta by a lumbar puncture. Through a puncture needle or catheter with a special injector, 40-60 ml of a water-soluble contrast medium is injected into the aortic lumen under pressure and a series of X-rays is performed.

A series of radiographs first receive an image of the aorta and the large branches that extend from it, including the renal arteries (early arterial phase), then the shadow of small intraorgan arteries (late arterial phase), then the overall increase in the intensity of the kidney shadow (nephrographic phase), weak shadow of the renal veins (veinogram), and finally, the image of calyxes and pelvis, since the contrast substance is excreted in the urine.

The renal arteries move away from the aorta almost at right angles at the level L, or the disk between it and LV. The diameter of the trunk portion of the renal artery is 1/3 -1/4 of the aortic diameter at this level, the length of the right artery is 5-7 cm, and the left artery is 3-6 cm. The outlines of arteries are even, their shadow is uniform and intense. A more detailed study of renal vessels is possible with their selective contrasting. The catheter is placed directly into the renal artery and a contrast agent is injected through it under pressure. On arteriograms, all the phases of contrasting kidneys noted above are recorded. If necessary, perform targeted radiographs. Renal arteriography is performed if there is a suspicion of renovascular hypertension (atherosclerosis, arteritis of the renal artery) and planning of operations for an abnormal kidney. Arteriography is also performed as a first stage for intravascular interventions, such as balloon dilatation, embolization, stent placement. As with other types of angiography, in the contrast study of renal vessels, the technique of digital subtraction angiography (DSA) is preferred. In order to perform selective venography, the catheter is inserted into the renal vein from the inferior vena cava.

CT scan. CT scan significantly expanded the scope of morphological studies of the kidneys, bladder and prostate. Kidney research is performed without special training in people of any age. On tomograms, the normal kidney is in the shape of an irregular oval with even and sharp outlines. In the anterior medial department of this oval, a renal sine appears at the level of LI-LII. At the same level, the renal arteries and veins are visible. To improve the visualization of the renal parenchyma and differential diagnosis of volumetric formations, the produced CT is produced.

At present, CT is the most informative method for detecting and differential diagnosis of volumetric processes in the kidney.

With its help determine the stage of malignant tumors of the kidneys. The method has high accuracy in the diagnosis of concrements (including X-ray negative), calcifications of the parenchyma and pathological formations, in the recognition of peripoint, periureteral and pelvic processes. CT is also effective in the recognition of traumatic kidney damage. Three-dimensional reconstruction on a spiral computer tomograph provides a urologist and an X-ray surgeon with a demonstrative picture of renal vessels. Finally, CT is the main method of visualizing the adrenal glands and diagnosing their pathological conditions - tumors, hyperplasia.

Magnetic resonance imaging. This method, in contrast to CT, allows you to obtain layered images of the kidneys in various projections: sagittal, frontal, axial. The image of the kidneys resembles that found on CT, but the boundary between the cortical and cerebral layers of the organ is better visible. Cups and pelvis containing urine are distinguished as low-density formations. With the introduction of a paramagnetic contrast agent, the intensity of the parenchyma image increases significantly, which facilitates the detection of tumor nodes. With MRI, the bladder is clearly visible, including parts of it such as the bottom and the top wall that are poorly discernible on CT. In the prostate gland, the capsule and the parenchyma are determined. The latter is normally homogeneous. Near the gland, in the behind-bubble tissue, you can see more dense formations - seminal vesicles.

Radionuclide study of the kidneys. Radionuclide methods are firmly established in the practice of urological and nephrological clinics. They make it possible to detect violations of kidney function in the initial stages, which is difficult to accomplish with the help of other methods. Clinicians are attracted to the physiology of the method of radioindication, its relative simplicity and the possibility of conducting repeated studies during the treatment of the patient. It is also important that radionuclide compounds can be used in patients with increased sensitivity to radiopaque substances. Depending on the research objectives, one of the radionuclide indicators is selected from the group of nephrotropic RFPs.

 Radionuclide study of the kidneys 

Radiometric determination of residual urine volume. In a number of diseases, especially if there is an obstruction to the flow of urine from the bladder, in the latter after urination there remains a part of the urine, which is called residual urine. A simple way to measure it is radionuclide research. After 1 1 / 2-2 hours after intravenous administration of RFP, excreted by the kidneys, the intensity of radiation above the bladder is measured. After the patient has emptied the bladder, determine the volume of excreted urine and again measure the intensity of radiation above the bladder.

Main clinical syndromes and tactics of radiation research

Tactics of radiation research, i.e. The choice of radiation methods and the sequence of their application, are developed taking into account the history and clinical data. To a certain extent, it is standardized, since in most cases the doctor deals with typical clinical syndromes: pain in the kidney, macrogemuria, urination disorders, etc. This circumstance justifies the use of typical schemes for examining patients, and such schemes are given below. However, the duty of the doctor is a thoughtful analysis of the features of the course of the disease in a particular patient and the introduction of the necessary adjustments into the general schemes.

Renal colic. The patient's condition is difficult. He has an attack of cramping pain in the kidney, often radiating to the lower abdominal cavity and pelvic region. Pain syndrome is often accompanied by nausea or vomiting, paresis of the intestine. Sometimes there is frequent urination. The patient shows thermal procedures, painkillers. The attending physician, the urologist or the surgeon, determines the indications for the radiation study and the time of its conduct.

Injury of the kidney and bladder. Macrohemuria. Damage to the kidney is often combined with trauma of neighboring organs and bones, therefore it is advisable to begin the examination of the victim with an overview of fluoroscopy and X-rays, in which the condition of the lungs, diaphragm, spine, ribs, abdominal organs is determined. Isolated injuries of the kidney include her bruising with the formation of subcapsular hematoma, violation of the integrity of the cup-and-pelvic system, rupture of the renal capsule with the formation of a retroperitoneal hematoma, crushing or detachment of the kidney.

Inflammatory diseases. Pyelonephritis is a nonspecific inflammatory process with a predominant lesion of the interstitial tissue of the kidney and its bowel-and-pelvis system. On radiographs and sonograms there is a slight increase in the affected kidney.

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

Tumors and cysts of the kidneys, bladder, prostate. Volumetric formation in the kidney, bladder or prostate is one of the most frequently detected syndromes of damage to these organs. Cysts and tumors for a long time can develop secretly, without causing severe clinical symptoms. Laboratory tests of blood and urine are very relative due to their nonspecificity and heterogeneity of the results. It is not surprising that radial methods are the decisive factor in determining and establishing the character of the volumetric process.

The main method of radial examination of the prostate gland is transrectal sonography. Valuable information about the nature of the tumor can be obtained using color Doppler mapping. CT and MRI are important refinement methods, allowing to judge the extent of the spread of the tumor process.

Malformations of the kidneys and urinary tract. Kidney anomalies do not always manifest themselves as specific clinical symptoms, but they need to be remembered, since these anomalies are observed frequently and, moreover, are not so rarely complicated by infection or stone formation. Of particular danger are the anomalies, in which the tumor is palpable tumor-like formations. It is clear that a doctor can suspect a tumor in the event that in fact it is not.

X-ray signs of kidney disease

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