Terms and definitions for computed tomography of the kidneys. Column bertini kidney what is fetal lobulation

06.06.2020

Kidney tumors account for 2-3% of all malignant neoplasms. Most often they occur at the age of 40-60 years. Renal cell carcinoma is noted in 80-90% of all kidney tumors. IN last years the probability of its detection increases, which is associated with both an increase in the number of all malignant tumors and early preclinical diagnosis. To recognize malignant tumors, first of all, it is possible to constantly improve and widely used ultrasound studies of the kidneys.

The first report on the use of ultrasound in the diagnosis of kidney tumors was published in 1963 by J. Donald. Since then, the accuracy of ultrasound diagnostics of kidney tumors has increased from 85-90% to 96-97.3%. When using modern tissue and second harmonic modes, as well as color Doppler and dynamic echocontrast angiography, the sensitivity of ultrasound (US) is 100% with a specificity of 92 and predictability of a positive test of 98%, and a negative one of 100%.

In the literature, there are often publications devoted to errors not only of ultrasonic, but also of other methods. radiation diagnostics... There is a point of view that up to 7-9% of all volumetric processes in the kidneys cannot be differentiated prior to operations for cysts, tumors, abscesses, etc. ... The picture of a kidney tumor with ultrasound and other radiation diagnostic methods can simulate many processes. Among them: various kidney anomalies; "complex" or mixed cysts; acute and chronic nonspecific inflammatory processes (carbuncle, abscess, chronic, including xanthogranulomatous pyelonephritis); specific inflammatory processes (tuberculosis, syphilis, fungal infections of the kidneys); changes in the kidneys with leukemia and lymphomas, including HIV infection; kidney infarction; organized hematomas and other reasons.

In this message, we will only talk about kidney abnormalities, which in the literature are defined by the term pseudotumor. With them, clinical manifestations are almost always absent or determined by concomitant diseases, and the establishment of the correct diagnosis is possible only by methods of radiation diagnostics (Fig. 1).

Figure: one. Variants of pseudotumors that mimic a tumor.

and) Fetal groin, "humped" kidney.

b) Bertin's pillar hypertrophy, enlarged "lip" over the hilum.

Materials and methods

1992-2001 observed 177 patients with different structures of the renal parenchyma by the type of renal pseudotumors. All of them repeatedly underwent ultrasound scanning of the kidneys, ultrasound dopplerography (USDG) of the vessels of the kidneys - 78, including using modes of the second and tissue harmonics and - 15, excretory urography (EU) - 54, X-ray computed tomography (CT) - 36, renal scintigraphy or emission computed tomography (ECT) with 99 m Tc - 21.

Research results

Fetal lobulation of the kidney (see Fig. 1) with multiple bulging along the lateral contour of the kidney was not considered in this report, since it did not cause the need differential diagnosis with a kidney tumor. Among 177 patients with pseudotumors of the kidneys, 22 (12.4%) had a variant of a lobular kidney - a "humped" kidney (Fig. 2).

Figure: 2. Pseudotumor "humped" left kidney.

and) Echograms.

b) A series of computer tomograms.

In 2 (1.2%) patients, an enlarged "lip" was noted above the hilum of the kidney (Fig. 3a-c).

Figure: 3 (a-c). Pseudotumor enlarged "lip" of the kidneys on both sides.

and) Echogram.

b) Excretory urogram.

in) Contrast-enhanced CT.

The most common cause of pseudotumor was "hypertrophy" of Bertin's pillars or "bridge" of the renal parenchyma - in 153 (86.4%) patients (Fig. 3d-f). "Bridges" of the parenchyma were noted not only with various doubling of the renal calyceal systems, but also with their various adhesions and incomplete turns of the kidneys.

Figure: 3 (d-f). Pseudotumor Bertin's hypertrophy (incomplete "bridge" of the parenchyma) in the middle section of the right kidney.

d) Echogram.

e) Excretory urogram.

e) Contrast-enhanced CT.

Differential diagnosis of pseudotumors and renal tumors required 37 (21%) patients. For this purpose, first of all, repeated "targeted" ultrasound scans were carried out using various additional ultrasound techniques in a urological clinic, as well as other methods of radiation diagnostics mentioned above. Only one patient with pseudotumor of the kidney underwent explorative lumbotomy with intraoperative ultrasound-guided biopsy to exclude the diagnosis of a tumor. In the remaining 36 patients, the diagnosis of pseudotumors of the kidneys was confirmed by radiation studies and ultrasound monitoring.

Difficulties and errors in radiological diagnosis in pseudotumors of the kidneys usually occurred at the first prehospital stages diagnostics. In 34 (92%) patients, they were associated with both objective difficulties in interpreting unusual echographic data and their incorrect interpretation due to insufficient qualifications of specialists and a relatively low level of diagnostic equipment. In 3 (8%) patients, an erroneous interpretation of X-ray computed tomography data was noted, when a discrepancy was noted with the data of repeated ultrasound scans and X-ray computed tomography in a urological clinic.

Tumors of the kidneys, which had their combinations with a pseudotumor in one kidney, were verified in 2 patients after nephrectomy, and pseudotumors - in one patient with biopsy under ultrasound control during exploratory lumbotomy; for the rest - with ultrasound monitoring over a period of 1 to 10 years.

Discussion

One of the most common reasons for simulating a kidney tumor on ultrasound, the so-called pseudotumor, is most often defined in the literature as Bertin's pillar hypertrophy.

As you know, along the periphery of the ultrasound cut of the kidney, the cortex forms intussusceptions in the form of pillars (columnae Bertin) between the pyramids. Often, Bertin's pillar goes deep enough beyond the inner contour of the parenchyma into the central part of the kidney - into the renal sinus, dividing the kidney more or less completely into two parts. The resulting peculiar parenchymal "jumper" is the non-absorbed parenchyma of the pole of one of the lobules of the kidneys, which merge into the kidney of an adult during ontogenesis. The anatomical substrate of the "bridges" is the so-called connective tissue defects of the parenchyma or prolapse of the latter into the sinus of the kidney. It includes cortical substance, Bertin's pillars, kidney pyramids.

All elements of the "bridge" are normal parenchymal tissue without signs of hypertrophy or dysplasia. They represent a doubling of the normal renal cortex or its additional layer located lateral to the calyx. The latter is a variant of the anatomical structure of the parenchyma, in particular, the corticomedullary relationship between the parenchyma and the renal sinus. They can be most clearly seen on ultrasound and computed tomographic sections of the kidney.

The absence of parenchymal hypertrophy or dysplasia in the so-called hypertrophy of Bertin's pillars or parenchymal "bridges" was confirmed by histological examinations biopsy material in one patient with parenchymal "bridges", taken before explorative lumbotomy for a kidney tumor, as well as in two patients with a morphological study of the kidneys removed due to a combination of tumor and pseudotumor in one kidney (parenchyma "bridges").

In this regard, in our opinion, the term most frequently encountered in the literature, the term hypertrophy of Bertin's pillars does not reflect the morphological essence of the substrate. Therefore, we, like a number of authors, believe that the term "jumper" of the parenchyma is more correct. For the first time in the domestic literature on ultrasound diagnostics, we applied it in 1991. It should be noted that the term "jumper" of the parenchyma had other names in the literature (table).

Table... Terms used to describe the "bridges" of the renal parenchyma (according to Yeh HC, Halton KP, Shapiro RS et al., 1992).

Origin or nature of the fabric	Terms	Authors
Hypertrophied or unusually wide tissue	Hypertrophied Bertin's pillar	Lafortune M et al., 1986 Wolfman NT et al., 1991 Leekman RN et al., 1983
	Focal cortical hyperplasia	Popky GL et al., 1969
	Wide arcade	Hodson CJ et al., 1982
Misplaced or misplaced fabric	Lobar dysmorphism	Carghi A et al., 1971 Dacie JE, 1976
	Incorrect position of the renal lobe	Carghi A et al., 1971
	Cortical folds	King MC et al., 1968
	"Kidney" within the kidney	Hodson CJ et al., 1982
	Cortical invagination and prolapse of Bertin's pillars	Lopez FA, 1972
Mass or pseudo-mass	Renal pseudotumor	Felson B et al., 1969 Lopez FA, 1972
	Glomerular zone of pseudotumor	Hartman GW et al., 1969
	Renal cortical nodule	Wolfman NT et al., 1991
	Primary cortical nodule	Thornbury JR et al., 1980
	Intermedial cortical mass	Netter F et al., 1979
Fetal anomaly	Aberrant lobule of renal tissue	Meaney TF, 1969
	Benign Cortical Caesura	Flynn VJ et al., 1972
	Cortical islet of the kidney	Flynn VJ et al., 1972
Evolved (perfect) anomaly	Failed attempt to duplicate renal parenchyma	Dacie JE, 1976
Supernumerary share	Additional renal lobe	Palma LD et al., 1990

Long-term experience of excretory urography has shown that the calyx-pelvic systems have an extremely large number of structural options. They are practically individual not only for each person, but also for the left and right kidneys in one subject. With the development and increasingly widespread use of ultrasound and CT, which makes it possible to trace both the internal and external contours of the renal parenchyma, in our opinion, a similar situation is developing with respect to the variants of the anatomical structure of the renal parenchyma. Comparison of echo and computed tomographic data with urographic data for various types of renal pseudotumors showed that there is a relationship between the anatomical structure of the parenchyma and the renal calyx systems. It is expressed in the congruence of the medial contour of the parenchyma in the echo or computed tomographic image with the lateral contour of the calyceal-pelvic systems, conventionally performed on excretory urograms or on computed tomograms with contrast enhancement. This symptom can be traced in the usual structure of the parenchyma and calyx-pelvic systems, as well as in the "bridge" of the kidney parenchyma, which is a variant of the anatomical structure. In a kidney tumor, which is an acquired pathological process, the congruence of the contours of the parenchyma and renal calyx systems is disturbed (Fig. 4).

Figure: 4. A symptom of the congruence of the contours of the parenchyma and the renal calyx-pelvis with an incomplete "bridge" of the parenchyma (explanation in the text).

findings

Thus, the typical ultrasound images of the "bridge" of the kidney parenchyma, "humpback" kidney and an enlarged "lip" above the hilum of the kidney without signs of expansion of the calyceal-pelvic systems do not require further examination.

If a differential diagnosis of pseudotumors and renal tumors is required, which was required in 37 (21%) patients, we propose the following diagnostic algorithm (Fig. 5).

Figure: five. Algorithm of radiological diagnosis for pseudotumor of the kidney.

Repeated ultrasound by qualified specialists of a higher class using ultrasound, mapping techniques, tissue and second harmonics.
X-ray computed tomography with contrast enhancement or excretory urography with comparison of uro- and echographic data and data of repeated "targeted" ultrasound.
The methods of choice are renal scintigraphy or emission computed tomography with 99 m Tc (false-negative results are possible in small tumors).
With the remaining suspicions of a malignant tumor, a biopsy under ultrasound guidance (only a positive result is of diagnostic value).
If the biopsy result is negative or the patient refuses biopsy and operative revision of the kidney, ultrasound monitoring is performed at a frequency of at least once every 3 months in the first year of observation, and then 1-2 times a year.

Literature

Demidov V.N., Pytel Yu.A., Amosov A.V. // Ultrasound diagnostics in urology. M .: Medicine, 1989. S. 38.
Hutschenreiter G., Weitzel D. Sonographic: einewertwolle erganzung der urologichen Diagnostic // Aktuel. Urol. 1979. Vol. Bd 10 N 2. P. 45-49.
Nadareishvili A.K. Diagnostic capabilities of ultrasound in patients with kidney tumor // 1st Congress of the Association of Specialists of Ultrasound Diagnostics in Medicine: Abstracts. Moscow. October 22-25, 1991. P.121.
Builov V.M. Complex application and algorithms of ultrasound scanning and X-ray diagnostics in diseases of the kidneys and ureters: Dis. ... doct. honey. sciences. M., 1995.S. 55.
Modern ultrasound diagnostics of kidney masses / A.V. Zubarev, I. Yu. Nasnikova, V.P. Kozlov et al. // 3rd Congress of the Association of Specialists of Ultrasound Diagnostics in Medicine: Abstracts. Moscow. October 25-28, 1999 p. 117.
US, CT, X-ray diagnosis of Renal Masses / R.K. Zeman, J.J. Croman, A.T. Rosenfield et al. // Radiographics. 1986. Vol.6. P. 351-372.
Thomsen H.S., Pollack H.M. The Genitourinary System // Global TextBook of Radiology. (Ed.) Petterson H. 1995. P. 1144-1145.
Lopatkin N.A., Lyulko A.V. Anomalies genitourinary system... Kiev: I am healthy, 1987. S. 41-45.
Mindel H.J. Pitfalls in Sonography of Renal Masses // Urol. Radiol. 1989. 11.87, No. 4, P. 217-218.
Burykh M.P., Akimov A.B., Stepanov E.P. Echography of the kidney and its pyelocaliceal complex in comparison with the data of anatomical and X-ray studies // Arch. Anat. Gistol. Embriol. 1989. Vol. 97. N9. S.82-87.
Junctional Parenchyma: Revised Definition of Hypertrophic Column of Bertin / H-Ch. Yeh, P.H. Kathleen, R.S. Shapiro et al. // Radiology. 1992. No. 185. P.725-732.
Bobrik I.I., Dugan I.N. Human kidney anatomy with ultrasound // Doctor. a business. 1991. No. 5. S. 73-76.
Khitrova A.N., Mitkov V.V. Kidney Ultrasound: A Clinical Guide to Diagnostic Ultrasound. M .: Vidar, 1996.T. 1.S. 201-204, 209, 212.
Builov V. Junctional parenchyma or hypertrophic column of Bertini: the congruence of their contours and calyceal-pelvic system // Abstracts of ECR \u200b\u200b"99, March 7-12. 1999. Vienna Austria.-Europ. Radiol. Supp. 1. Vol. 9. 1999. S. 447.
Builov V.M., Turzin V.V. Ehotomography and excretory urography in the diagnosis of "bridges" of the renal parenchyma // Vestn. rentgenol.radiol. 1992. No. 5-6. S. 44-51.
Builov V.M., Turzin V.V. Diagnostic value of atypical "bridges" of the parenchyma in renal sonography // 1st Congress of the Association of Specialists of Ultrasound Diagnostics in Medicine: Abstracts. Moscow. October 22-25, 1991. P. 121.
Builov V.M. Questions of terminology and symptom of congruence of the contours of "hypertrophied" Bertini columns or "bridges" of the parenchyma and renal calyx systems // Vestn. rentgenol. and radiol. 2000. N 2.S. 32-35.
Builov V.M. Algorithm for radiological diagnosis of renal pseudotumors // Abstracts of reports. 8th All-Russian. Congress of Radiologists and Radiologists. Chelyabinsk-Moscow. 2001.S. 124-125.

In our observations, it was detected in 0.2% of patients, moreover, in most cases in boys. Echodiagnostics presents certain difficulties that increase when this anomaly is combined with various diseases (hydronephrosis, cysts, polycystic disease, hematomas, paranephritis, tumors, trauma).

An unaffected horseshoe kidney is always located lower than a normal kidney, is large, but never gains the sum of two normal renal sizes, the zone of the parenchyma and the calyx-pelvis system is well delineated. Visualization and differentiation are improved with the application of water loading, which allows for good differentiation of the dilated pelvis. It should be noted that it is very difficult to determine echographically which poles the kidneys are spliced, except in cases when, when viewed through the anterior abdominal wall, it is possible to locate the adrenal glands at opposite poles, and this is possible only with an anomaly of the left kidney.

Galetic kidney

This anomaly is very rare and is formed as a result of the uniform action of forces small intestine during the movement of the kidneys from the small pelvis to the lumbar region. When they are delayed in the pelvis, fusion occurs throughout. The kidney is located low in the pelvis as a flat-oval-elongated formation with clear contours, with a delineation of the parenchyma zone and the calyx-pelvic system without differentiating the fusion site. May be mistaken for a tumor. Echodiagnostics of the biscuit-like kidney is difficult when combined with various diseases. Priority for excretory urography.

Asymmetric forms of fusion include kidneys that have grown together in the form of the Latin letters S, I and L. With this anomaly, the kidneys are fused with opposite poles due to the uneven effect of the forces of the small intestine during their advance from the small pelvis to the lumbar region. Longitudinal axes S and 1-shaped accrete buds are parallel. The S-shaped kidney is located in the pelvis in a horizontal or oblique position, and the I-shaped kidney is located vertically and parallel to the inferior vena cava and the abdominal aorta.

With an L-shaped kidney, the longitudinal axes are perpendicular and are located in the pelvis in a horizontal position. It should be noted that this anomaly is easily confused with a horseshoe kidney. Usually, abnormal kidneys have clear contours with a well-differentiated zone of the parenchyma and often zones of the two calyx-pelvic systems. Sometimes with an S-shaped kidney, it is possible to isolate the isthmus (the place of fusion). Despite the fact that echography reveals the presence of abnormal kidneys, priority in their differential diagnosis for excretory urography.

Quantity anomalies

Double kidney

The most common anomaly in the number of kidneys (approximately 4%) is kidney doubling, which is unilateral and bilateral, complete and incomplete.

Paired kidney

With full doubling, there are two collecting systems - two pelvis, two ureters and two vascular bundles. The echogram clearly shows the pelvis, the beginning of the ureters, sometimes it is possible to isolate the vascular bundles.

A half-doubled kidney differs from a complete one in that it feeds on one vascular bundle. The ureter can be doubled at the top and drain into the bladder with one or two orifices. On the echogram, the doubled kidney looks elongated and is present characteristic feature separation of the zones of the parenchyma and the cup-pelvis system.

Difficulties in echographic differentiation occur with pyelonephritis, hydronephrosis, urolithiasis and with tumors of one of the halves of the double kidney. The complete anatomical picture of a duplicated kidney can only be seen radiographically.

This pathology is extremely rare. Paired buds can be unilateral and bilateral, the same or different in size. According to our data (in the available literature, a description of this pathology was not found), a unilateral paired kidney was detected in 5 women of age and a bilateral one in 2 pregnant women aged 21 and 28 years. In 6 out of 7 cases identified by us, paired kidneys were of the same size, on average 8.2-3.6 cm. For the width of the kidney, we took only 1/2 of the width of the parenchyma zone in the fused part of the kidneys.

A characteristic feature is their longitudinal fusion with lateral surfaces. The echo structure of paired kidneys does not differ from that of a normal kidney, that is, the zones of the parenchyma and the calyx-pelvis system are very clearly distinguished. A special feature is that the width of the parenchyma zone at the site of fusion does not exceed the value in the non-fusion part of the kidneys. According to the echo picture, it can be assumed that fusion occurs at the level of the entire thickness of the parenchyma of both kidneys. The option of complete longitudinal doubling of the kidney is not excluded. The ureters behave in the same way as in a double kidney.

Renal parenchymal anomaly

Renal parenchymal abnormalities include agenesis, aplasia, hypoplastic kidney, accessory (third) kidney, accessory lobule, and cystic parenchymal anomalies - polycystic, multicystic, solitary cyst, multilocular cyst, spongy kidney, megacalycosis, and calyx diverticulum.

Agenesis

Congenital absence of one or both kidneys. With unilateral agenesis on this side, the specificity of the structure of the kidney is not located, however, sometimes it is possible to locate an enlarged adrenal gland. On the opposite side, a hypertrophied kidney, defective in echo construction, is located.

However, it should be remembered that the absence of a kidney location in the anatomical place does not indicate the presence of agenesis. The final diagnosis can be made only after detailed echographic and radiological studies. Bilateral agenesis is very rare and is diagnosed in the fetus in II and III period pregnancy, when all organs are developed. At the same time, a thorough echographic examination does not reveal the echostructure of the kidneys and bladder. The study is carried out with difficulty, since with this anomaly, oligohydramnios is always present. Fruits with this anomaly are born dead.

Aplasia

Deep underdevelopment of the renal parenchyma with frequent cases of absence of the ureter. There can be one- and two-sided.

With unilateral aplasia, the specificity of the structure of the kidney is absent and an oval-elongated formation with indistinct blurred contours is localized, heteroechoic (of different acoustic density), although small cysts and calcifications can be located. It does not appear clinically and is an echographic finding in the study of the kidneys.

Bilateral aplasia is extremely rare. At the same time, the image of the kidneys and urinary bladder cannot be detected in the fetus.

Hypoplastic kidney

Congenital decrease in the size of the kidney. On the echogram, the kidney is reduced in size (on average, it has a length of 5.2 cm, a width of 2.4 cm), the zones of the parenchyma and the pelvis-pelvis system are narrowed, but the specificity of the structure of these zones remains.

In 3 patients, we observed a dwarf kidney 3-2 cm in size. The contours of the kidney are erased, the parenchyma is heterogeneous in echogenicity; there is no division into zones.

It should be remembered that it can be very difficult to distinguish a hypoplastic kidney from a wrinkled kidney, in which the size is also reduced, but the latter has a blurred contour and division into zones; such a kidney is poorly delimited from the surrounding tissues.

Additional (third) kidney

Extremely rare. We have identified 2 cases. The accessory kidney is usually located below the main one and may be slightly smaller than it. In our cases, the main and accessory kidneys were located in the horizontal plane and had the same size, but slightly less than the generally accepted average values \u200b\u200bfor this age (7.1-2.8 cm). The parenchyma and calyx-pelvic system in both kidneys stand out clearly. The ureter of the accessory kidney can drain into the main ureter or independently into the bladder.

An additional lobule of one of the buds may be one (or several) and is located more often at the poles, it is located as a small oval formation with clear contours; the echo structure of the lobules is similar to that of the main kidney tissue. Sometimes additional lobules are easy to mistake for the adrenal gland, although their echo structure is somewhat different, sometimes they can be confused with a bulky formation that grows exophytically.

Anatomical variations of a normally functioning kidney

There are anatomical variations in the structure of the parenchyma and the renal calyx-pelvis system. It should be noted right away that they have no clinical significance, however, some of them may pose diagnostic problems for the researcher.

A parenchymal defect is rare and is located in the form of an echogenic zone of a triangular shape, the base of which is associated with the fibrous capsule, and the apex with the wall of the renal sinus.

Kidney with an oval-convex uneven outer contour

It is quite common. It is characterized by isolated hypertrophy (bulging in the form of a hump) of the parenchyma towards the outer edge of the middle third of the kidney. An inexperienced specialist may mistake it for a tumor with exophytic growth or a carbuncle (with the latter, an acute clinic is present).

Uneven lobular kidney

Usually occurs in children under 2-3 years of age. Rarely does this phase of the embryonic structure persist in adults. It is characterized by a uniform division into 3-4 bulging zones of low echogenicity on the outer surface (parenchyma of the lobules).

Kidney with an isolated zone of parenchymal hypertrophy inward

This anomaly of the parenchyma is quite common, it is characterized by isolated hypertrophy and bulging in the form of a pseudopod between the two pyramids to the calyx-pelvic system, which, in the absence of a clinic, we tend to consider a variant of the individual norm. It can be mistaken for a tumor, and therefore patients with exophytic and endophytic additional growth of the parenchyma should be subjected to invasive research methods.

Polycystic kidney disease

Congenital, always bilateral cystic anomaly parenchyma of the kidneys.

Before the introduction of echography, especially in real time, the diagnosis of polycystic disease presented great difficulties, since the percentage of correct diagnostics by X-ray methods does not exceed 80. In our observations of more than 600 patients, echographic diagnostics was correct in 100% of cases. The polycystic kidney is always enlarged in size, the contours are uneven, oval-convex, the echo structure is not differentiated, only strips of the parenchyma and many rounded anechoic formations (cysts) of different sizes are visible, separated by thin echogenic stripes-septa. Sometimes a polycystic kidney takes the form of a bunch of grapes. But in most cases, several large, up to 5-6 cm in diameter, cysts surrounded by many small ones are located. Sometimes, with dynamic observation of the patient, one can observe the disappearance of large cysts, their ruptures.

The examination is done from the back, but the visualization of the right kidney is better done through the liver. It should be noted that with a significant kidney size and the presence of many cysts, sometimes the liver is only partially visible or not visible at all, and it is possible to erroneously diagnose polycystic liver disease, which is extremely rare.

Multicystic dysplasia

Congenital anomaly, which is often unilateral, since bilateral is not compatible with life. The multicystic kidney is usually large in size, characterized by uneven contours, the parenchyma does not differentiate and is completely replaced by cysts of various sizes, usually 2-3 large ones. For the purpose of differential diagnosis of polycystic and multicystic, use x-ray methods research. Multicystic kidney disease is characterized by high obliteration of the ureter.

Solitary cyst

Distinguish between congenital and acquired renal cysts. Congenital cysts are detected in the fetus in the II and III trimesters of pregnancy or more often in childhood. Acquired cysts are more common after 40 years. There are single and multiple, but no more than 2-3 in one kidney. They are located as rounded formations of different sizes: the minimum is 0.5 cm, the maximum is over 10 cm in diameter. They come from the parenchyma of the kidney and have clear contours, are devoid of echo signals, are located both on the surface and in different parts of the kidney.

A certain difficulty is the clarification of the location of the cyst; first of all, this applies to parapelvic cysts located in the area of \u200b\u200bthe kidney hilum. In some cases, it is difficult to differentiate them from an enlarged pelvis, hydronephrosis, which may have a similar oval shape. In this regard, it should be remembered that in the case of hydronephrosis during echolocation of the kidney, in different scans, an interruption of the contours of the fluid formation is almost always found, that is, the connection with the pelvis and the pelvic-ureteric segment and the calyx, while with parapelvic cysts, interruption of the contours of the fluid formation being located is not observed.

It should be remembered that the image of cysts of the right lobe of the liver or the right half of the abdominal cavity, in particular the mesentery of the intestine in Crohn's or ovarian disease, may be layered on the right kidney. A cyst of the left kidney can be mistaken for a cyst of the lower pole of the spleen, the tail of the pancreas, the left half of the abdominal cavity, the left ovary, or fluid in the stomach with poor evacuation. Such diagnostic errors are unacceptable, because they lead to serious complications, since the access for surgical intervention in these pathologies is different. To avoid mistakes, it is necessary, by changing the position of the body, to carefully differentiate the contours of the kidney in different echographic scans. In doubtful cases, repeated ultrasound examinations and laparoscopy are indicated.

Echography allows for dynamic monitoring of the growth and condition of cysts (suppuration, rupture, resorption). The dynamics of the development of cysts is of great clinical importance, since their growth is associated with atrophy of the renal parenchyma, leading to hemodynamic disturbances and arterial hypertension. Echography helps to clarify the moment of possible surgical intervention or conservative treatment, provides the conditions for conducting targeted diagnostic or therapeutic biopsy.

Dermoid cysts

These are congenital unicameral, rarely multi-chambered rounded formations, outlined by an echogenic capsule. They can be located in various parts of the body, rarely in internal organs and very rarely in the kidneys. They are more common in girls in early childhood, although they can also occur in adults, moreover, be an accidental find. Depending on their content (hair, fat, bone and others) the contents of the formation have different echogenicity - part of the cyst may be high, and part - low (liquid). The wall of the dermoid cyst is thickened, has a high echogenicity, and sometimes it undergoes calcification and is located as a rounded highly echogenic ring, clearly visible on X-ray. It should be noted that sometimes a dermond cyst is echographically difficult to distinguish from a chronic abscess, decay of a cavity and a tumor, hypernephroma and Wilms' tumor. The diagnosis in such cases can be confirmed with a puncture aspiration biopsy or with surgery.

Multilocular cyst

A very rare anomaly (2 cases were identified), characterized by the replacement of a section of the renal parenchyma with a multicameral cyst, which is located as a multicameral anechoic formation, separated by narrow echogenic septa. When a large size is reached, the echo picture is the same as with a multi-chamber echinococcal cyst. Differentiation is very difficult. The only distinguishing feature is that an active echinococcal cyst gives rapid growth compared to a multlocular cyst (in household the patient usually has animals - carriers of echinococcosis).

Spongy kidney

A rare anomaly in which the collecting ducts are dilated.

More often males suffer. In this case, the kidney can be increased in size, a uniform cystic lesion of the pyramids is characteristic, as a rule, bilateral, without the involvement of the cortex in the pathological process. Cysts are usually small in size, 3 to 5 mm in diameter, directed towards the center of the kidney. Although many small cysts can also be found on the surface of the kidney, making it uneven. Many small stones are located in the area of \u200b\u200bthe pyramids. When pyelonephritis is attached, echo diagnosis is difficult.

Megacalycosis (renal calyx dysplasia)

Congenital enlargement of the renal calyces associated with the underdevelopment of the renal pyramids. Usually this anomaly is unilateral, although cases of bilateral lesions have been described. In this case, all cups are affected.

On the echogram, all the cups are significantly expanded, have a rounded shape, the pelvis, as a rule, if pyelonephritis has not joined, is not expanded, the ureter is freely passable for a contrast agent during X-ray examination.

Accumulation of uric acid salts and small stones can be located. Echography of this pathology only allows us to assume the final diagnosis for excretory urography and retrograde pyelography, where the cavity of the cyst, a narrow passage, communicating with the renal calyx, is clearly visible.

Calyx diverticulum

Congenital cystic formation associated with a small renal calyx through a narrow channel.

Megaureter

Congenital unilateral, rarely bilateral segmental expansion along the entire length of the ureter, from 3 mm to 2-3 cm or more, the ureter is located as an uneven width of an anechoic tube over the narrowed distal segment.

The length of the ureter can range from 0.5 to 4-5 cm, more often the left ureter is affected. A megaureter can be primarily obstructive (congenital), secondary obstructive (acquired) due to inflammatory processes, postoperative scars and other causes, and primarily non-obstructive (idiopathic). Megaureter, especially primarily obstructive, always leads to hydronephrosis and hydrocalicosis.

Ureterocele

One of the rare anomalies of the ureter, resulting from the narrowness of its orifice, in which all layers of the intramural ureter expand, bulging in the form of an oval echo-negative formation into the bladder cavity from one or both sides. The ureterocele cavity can contain urine - from a few milliliters to the volume of the bladder.

Ureterocele is difficult to differentiate from a diverticulum or an echinococcal cyst located at the orifice of the ureter.

Early diagnosis of ureterocele is of great importance, as it allows the patient to timely save the patient from possible dilatation of the upper urinary tract and the development of pyelonephritis and secondary cystitis.

Renal vascular anomaly

This area of \u200b\u200bpathology for modern echography, even with the use of Doppler, is little or, more precisely, only partially available. It only allows us to assume the presence of any vascular pathology when comparing structural changes in the renal parenchyma.

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Difficulties and errors of ultrasound and X-ray diagnostics of renal pseudotumors

State Medical Academy,

MySono-U6

Introduction

Kidney tumors account for 2-3% of all malignant neoplasms. Most often they occur as they grow older. Renal cell carcinoma is noted in 80-90% of all kidney tumors. In recent years, the probability of its detection has been increasing, which is associated with both an increase in the number of all malignant tumors and early preclinical diagnosis. To recognize malignant tumors, first of all, it is possible to constantly improve and widely used ultrasound studies of the kidneys.

The first report on the use of ultrasound in the diagnosis of kidney tumors was published in 1963 by J. Donald. Since then, the accuracy of ultrasound diagnostics of kidney tumors has increased from 85-90% to 96-97.3%. When using modern ultrasound scanners operating in tissue and second harmonic modes, as well as color Doppler and energy mapping and dynamic echocontrast angiography, the sensitivity of ultrasound examination (US) is 100% with a specificity of 92 and a predictability of a positive test of 98%, and a negative one - 100% ...

In the literature, there are often publications devoted to errors not only of ultrasound, but also of other methods of radiation diagnostics. There is a point of view that up to 7-9% of all volumetric processes in the kidneys cannot be differentiated prior to operations for cysts, tumors, abscesses, etc. ... The picture of a kidney tumor with ultrasound and other radiation diagnostic methods can simulate many processes. Among them: various kidney anomalies; "Complex" or mixed cysts; acute and chronic nonspecific inflammatory processes (carbuncle, abscess, chronic, including xanthogranulomatous pyelonephritis); specific inflammatory processes (tuberculosis, syphilis, fungal infections of the kidneys); changes in the kidneys with leukemia and lymphomas, including HIV infection; kidney infarction; organized hematomas and other reasons.

Figure: 1. Variants of pseudotumors mimicking a tumor.