Environmentally related diseases of the urinary tract

Nephrotoxicity from exposure to therapeutic agents and chemicals in the environment and workplace results in a broad spectrum of clinical renal disease that may mimic disorders from other causes. Nephrotoxic agents may, in fact, be responsible for some fraction of renal disease of undetermined etiology. Specific diagnosis and treatment by removal from exposure to the toxic agent is more likely in the early phase of the disorder. Measurement and characterization of proteinuria provides the most sensitive and reliable method of early detection. Increased urinary excretion of serum proteins with molecular weight in excess of 50,000, such as albumin and transferrin, is an early indicator of glomerular injury. Low-molecular-weight proteinuria (beta 2-microglobulin or retinol-binding protein) and enzymuria, particularly excretion of NAG, are sensitive indicators of renal tubular cell injury. Tests that reflect hypersensitivity reactions are often indicative of immunologically mediated nephrotoxicity but are not specific for the kidney. Cancers of the kidney and urinary bladder appear to be increasing and are most common among the socially active and affluent. Susceptibility of the urinary tract to toxicity and carcinogenicity reflect contact of excreted toxins with the epithelial cells of nephrons and urinary bladder.     

Differentiation of glomerular, tubular, and normal proteinuria: determinations of urinary excretion of β2-microglobulin, albumin, and total protein

A low molecular weight beta(2)-globulin (beta(2)-microglobulin), albumin, and total protein were measured in concentrated 24-hr urine specimens from 20 healthy subjects and 30 patients with clinical proteinuria of glomerular or tubular type. Classification of proteinuria was made on the basis of clinical diagnosis and size distribution of urinary proteins after gel chromatography. The molecular radii (Stokes' radii) of beta(2)-microglobulin and albumin, estimated by gel chromatography, were 15 A and 35 A.The average 24-hr urinary excretion in healthy subjects was 0.12 mg for beta(2)-microglobulin, 10 mg for albumin, and 80 mg for total protein. The patients with renal glomerular disorders had normal or only somewhat increased excretion of beta(2)-microglobulin, despite considerably increased excretion of albumin and total protein. Most of the patients with tubular dysfunction excreted large amounts of beta(2)-microglobulin, although they excreted normal or only slightly increased amounts of albumin and only moderately increased quantities of total protein. Consequently, the ratio or urinary albumin/urinary beta(2)-microglobulin was high in glomerular proteinuria (1100: 14,200), intermediate in normal proteinuria (33: 163), and low in tubular proteinuria (1.0: 13.3). Determinations of urinary clearances of beta(2)-microglobulin and albumin in four healthy subjects and 11 patients indicated that increased excretions of the two proteins were associated with increased clearances. The results suggest that quantitative determinations of urinary beta(2)-microglobulin and urinary albumin may be useful for detecting disorders of the renal handling of plasma proteins. The findings also seem to suggest a selective tubular reabsorption of the two proteins.Estimates on sera revealed a close correlation between serum levels of beta(2)-microglobulin and creatinine and also a greatly raised serum concentration of beta(2)-microglobulin after bilateral nephrectomy.     

Determination of urinary lysozyme for potential detection of tubular dysfunction in diabetic nephropathy

Seeking to study whether measurement of lysozyme (EC 3.2.1.17) in urine by a reliable radioimmunoassay can provide a suitable index of renal tubular function and how lysozymuria develops in temporal relation to proteinuria in diabetic nephropathy, we have compared the urinary excretion of lysozyme and beta 2-microglobulin with the 15-min excretion rate of phenolsulfonphthalein in 39 patients with Type 2 (non-insulin-dependent) diabetes and investigated the temporal relation between the onset of lysozymuria and proteinuria in 15 patients with Type 1 (insulin-dependent) diabetes. The concentrations of lysozyme and beta 2-microglobulin in urine increased in proportion to the decrease in the rate of excretion of phenolsulfonphthalein in these patients. The coefficient of correlation between lysozyme concentration and the 15-min excretion rate of phenolsulfonphthalein (r = -0.70) was higher than that between beta 2-microglobulin concentration and the 15-min excretion rate of phenolsulfonphthalein (r = -0.46). Abnormally high lysozymuria, suggesting the existence of tubular dysfunction, was demonstrated in six of the patients with Type 1 diabetes who showed no proteinuria or only a slight increase in urinary protein excretion. Lysozymuria may thus be added to a list of the indicators for diabetic nephropathy.     

Behaviour of urinary excretion of lysozyme in renal diseases and in urinary tract infections (author's transl)]

Urinary excretion of lysozyme was investigated in a group of 66 patients with various renal diseases, nephrolitiasis and urinary tract infections. The results obtained demonstrate that the amount of the enzyme excreted is related to the entity of tubular damage whereas is not with glomerular damage. No correlation was found between lysozyme excretion neither to the degree of proteinuria neither to the amount of leukocytes and bacteria in the urine. In patients with urinary infections urinary lysozyme increases only when there is a tubular injury of some entity. In 90 pediatric patients with urinary infection and pyelonephritis lysozyme in the urine was found only in two cases. Therefore urinary lysozyme determination cannot be considered for the detection of early tubular injury and is not a helpful diagnostic tool in urinary tract infections.     

Interpreting complex urinary patterns with MDI LABLINK: a statistical evaluation

The measurement of urinary marker proteins is not a generally accepted laboratory practice because the results are difficult to interpret. MDI-LABLINK is software for classifying patterns of specific urinary marker proteins. The interpretations are completely user definable thanks to a specific 'pattern definition database'. Our interpretation set is based on Hofmann and Guder's work in measuring and interpreting single urinary proteins. We include additional marker proteins in order to adapt Boesken's SDS-PAGE classification. During the last 3 years, 1905 patterns were fully differentiated and identically interpreted. Firstly, the samples were classified into three patterns: normal (25.8%), predominantly glomerular (27.2%, selective, unselective, mixed, and with additional tubular proteins) and predominantly tubular (36.9%, complete/incomplete form, with additional glomerular proteins); 8.9% showed postrenal proteinuria. Secondly, glomerular selectivity measured by using urinary transferrin/IgG ratio alone correlates well with the established SI index (the ratio between IgG and transferrin clearances). Thirdly, the creatinine concentration substantiates the validity of the sample. The quality of the preanalytical phase can be improved through the ongoing education of the medical staff. Finally, measurement of urinary albumin and alpha-1-microglobulin is mandatory where kidney disease is suspected, has to be ruled out, or requires close monitoring, even when the total protein concentration is normal.     

Renal glomerular and tubular impairment during strenuous exercise in young women

Creatinine, total protein, albumin and beta2-microglobulin were measured in the urine of fifteen healthy women before and after strenuous short-term exercise. The heavy intermittent load produced an increased urinary excretion of total protein, albumin and beta2-microglobulin, while creatinine was unaffected. The renal clearance of albumin and beta2-microglobulin showed very high values after stopping the exercise. However, 45 min after the end of exercise, total protein returned to initial values while albumin and beta2-microglobulin remained high. The urinary ratio between beta2-microglobulin and albumin is higher in urine collected after exercise than in normal proteinuria. This implies that post-exercise proteinuria is of glomerular and tubular origin.     

Dose-dependent effect of rosuvastatin treatment on urinary protein excretion

Concerns have been raised because of observations of proteinuria associated with rosuvastatin treatment. In this open-label study, a potential dose-dependent effect was investigated of rosuvastatin on urinary protein excretion and renal function parameters in 90 hyperlipidemic patients randomly assigned to rosuvastatin 10 mg/day (n = 45) or 20 mg/day (n = 45). Urinary samples were collected from patients and 40 age- and gender-matched controls to determine electrolyte, uric acid, creatinine, and protein (total, albumin, IgG, and alpha1-microglobulin) levels at baseline and after 12 weeks. A dose-dependent increase in the excretion of alpha1-microglobulin (17.6% in rosuvastatin 10 vs 34.9% in rosuvastatin, 20 mg/day; P = .03 for the comparison between groups) was observed. A trend toward an increase in the estimated glomerular filtration rate was noted in only patients receiving 20 mg/day of rosuvastatin. These findings indicate that rosuvastatin treatment increases the urinary excretion of alpha1-microglobulin urinary excretion in a dose-dependent manner without adversely affecting renal function.     

Radiologic findings in acute urinary tract obstruction

Acute urinary tract obstruction, a common disease in daily practice, often requires performance of emergency intravenous urography (IVU). However, the spectrum of urographic abnormalities seen with acute obstruction has not been thoroughly addressed. The purpose of this study was to explore the IVU findings in patients with acute urinary tract obstruction. Records of 380 patients who underwent IVU in our hospital during a 6-mo period were reviewed for IVU evidence of acute urinary tract obstruction. Of the 380 patients, 53 (14%; 39 men, 14 women; average age = 43 yr) had acute urinary tract obstruction. All obstructions except one were located in the lower one-third of the ureter. The causes of acute urinary obstruction included ureteral stones in 34 (64%), ureteral edema or lucent stones in 16 (30%), neoplasms in 2 (4%), and inflammatory disease in 1 (2%). Abnormal radiologic findings were hydroureter in 46, nephropyelographic delay in 36, hydronephrosis in 35, interureteric ridge edema in 11, persistent dense nephrogram in 6, urine extravasation in 5, vicarious excretion in 1, striation in 1, and stricture in 1. Radiographic results were normal in one patient. The most common clinical indications of acute ureteral obstruction are flank pain and hematuria, and calculi are the major cause. In one-third of patients, radiopaque calculi are not detectable with IVU during acute urinary tract obstruction. A careful and thorough evaluation of the IVU should be performed in patients with clinical indications of acute urinary obstruction.     

Assessment of renal function: selected developments

Tests commonly used to assess the glomerular filtration rate (GFR) and to detect renal tubular damage are critically reviewed. Creatinine clearance which is frequently used for assessment of the GFR is prone to several errors. The plasma creatinine can be used to provide a rough guide but for reliable measurement of the GFR, 51Cr-EDTA clearance is recommended. Measurements of the urinary excretion of low molecular weight proteins, enzymes and kidney tissue proteins have been used to detect tubular damage. Of the low molecular weight proteins excreted, beta-2-microglobulin is unstable and measurement of retinol-binding protein or alpha-1-microglobulin is recommended for the detection of chronic renal tubular malfunction. Of the many enzymes that have been studied, urinary N-acetyl-beta-D-glucosaminidase or alanine aminopeptidase are recommended as being the most useful for the early detection of acute renal tubular damage. Among renal tissue proteins that have been measured in urine adenosine-deaminase-binding protein, a tubular brush border antigen appears to have considerable potential for providing early warning of renal allograft rejection.     

The gelatin-derived plasma substitute Gelofusine causes low-molecular-weight proteinuria by decreasing tubular protein reabsorption

PURPOSE: Proteinuria is frequently encountered in patients in the intensive care unit, most likely as a result of renal tubular cell injury. It has been reported that gelatin-derived plasma substitutes contribute to an increase in renal protein excretion. The aim of this study was to investigate the magnitude and the mechanism of the proteinuric effect of Gelofusine, a modified gelatin. MATERIALS AND METHODS: In six healthy male subjects, renal hemodynamics and urinary protein excretion were measured before and after infusion of 330 mL of Gelofusine. RESULTS: Gelofusine had a minor effect on blood pressure, glomerular filtration rate, effective renal plasma flow, and on urinary excretion of immunoglobulin, and albumin. In contrast, there was a major increase in the urinary excretion of the low-molecular-weight proteins beta2-microglobulin (from 0.06 +/- 0.04 to 43.52 +/- 11.75 microg/min; P <.01) and alpha1-microglobulin (from 11 +/- 8 to 72 +/- 24 microg/min; P <.01). The urinary excretion of N-acetyl-beta-D-glucosaminidase (beta-NAG) remained unchanged, suggesting that there was no significant renal tubular cell injury. CONCLUSIONS: When analyzing proteinuria in patients in the intensive care unit it should be considered that Gelofusine increases the urinary excretion of proteins, in particular those of low molecular weight. This effect is most likely due to competitive inhibition of tubular protein reabsorption.     

肾移植后尿路并发症的发生及治疗:1 223例次资料回顾

背景:尿路并发症是肾移植后常见外科并发症之一,严重危及移植肾功能,甚至患者生命.肾移植后尿路并发症主要包括尿瘘、输尿管梗阻、输尿管返流等.目的:回顾性分析肾移植后尿路并发症的发生及处理情况.方法:选择解放军第二军医人学火坪医院野战外科研究所泌尿外科于1993-12/2007-04开展的1 223例次同种异体肾移植的临床资料,根据供肾输尿管情况及受者下尿路情况,尿路重建采用输尿管-膀胱黏膜下隧道吻合法948例次,输尿管-输尿管端端吻合法275例次.肾移植后发生的尿瘘、移植肾输尿管梗阻、膀胱输尿管根据不同原因采取相应处理方法,主要为外科治疗.分析尿路并发症的发生原因,观察治疗后移植肾功能变化,记录移植肾3年存活率.结果与结论:1 223例次肾移植共发生尿路并发症92例(7.5%),其中尿瘘43例(3.5%),35例经再次手术治愈;输尿管梗阻35例(2.9%),29例经外科手术治愈;膀胱输尿管返流14例(1.1%),6例经外科手术治愈.70例行外科处理,其中移植肾输尿管-自体输尿管吻合35例(占50%),输尿管-膀胱重新再植18例(占25.7%),泌尿内镜治疗11例(占15-7%),其他手术6例(占9.6%).除1例由于供肾肾孟、输尿管全段坏死行移植肾切除外,其余患者肾功能均得到恢复,未发生由于尿路并发症导致的移植肾丢失及患者死亡.出现尿路并发症及无尿路并发症移植.肾3年存活率差异无显著性意义(P>0.05).提示肾移植后尿路并发症大都需要外科处理,其中移植肾输尿管-自体输尿管吻合是常用术式,处理得当对移植肾远期存活率无明显影响.     

The effects of arginine, dextran and Haemaccel infusions on urinary albumin, beta 2-microglobulin and N-acetyl-beta-D-glucosaminidase

Male volunteers were infused with L-arginine dextran and Haemaccel. Arginine (0.5 g/kg body weight infused over 30 min) resulted in transient highly significant increases in urinary albumin (p less than 0.001), beta 2-microglobulin (p less than 0.001) and N-acetyl-beta-D-glucosaminidase [NAG] (p less than 0.001). These effects lasted less than 120 min. Dextran 40 and 70 (500 ml infused over 2 h) did not affect urinary albumin, beta 2-microglobulin or NAG excretion. Haemaccel (8 ml/kg body weight infused over 2 h) resulted in significant increases in urinary albumin (p less than 0.05) and beta 2-microglobulin (p less than 0.01) during the second hour of the infusion. It also caused a biphasic increase in urinary NAG excretion, the initial peak (p less than 0.05) coinciding with the peak of albumin and beta 2-microglobulin excretion. The second peak which was more defined (p less than 0.01) occurred 21-24 h after the beginning of the infusion. Neither arginine or Haemaccel have been reported to be nephrotoxic whereas dextran infusions are a well recognised cause of acute tubular necrosis. These data indicate that increases in urinary beta 2-microglobulin and NAG are not always reliable indicators of nephrotoxicity or renal tubular cell damage.     

Urinary excretion of albumin and beta 2-microglobulin in a population from an area where Balkan nephropathy is endemic.

The urinary excretion of albumin and beta 2-microglobulin in a population of 294 persons, living in an area where Balkan nephropathy is endemic, has been studied. In fifty-six (about 19%) of the subjects the beta 2-microglobulin concentration was above the +2 SD level for a reference group of healthy individuals from non-endemic areas. Albumin elevation was found in forty-four (about 15%) of the cases. In twenty-one of the subjects the urinary concentration of both beta 2-microglobulin and albumin were increased, in sixteen of these cases the relationship between the two proteins was consistent with tubular proteinuria. An increased beta 2-microglobulin excretion is considered to be a sign of Balkan nephropathy. Radioimmunoassay of the protein is sensitive enough to detect tubular proteinuria at an early stage and is suggested as a suitable screening test for the disease.     

Quantitative assessment of urinary protein and enzyme excretion--a diagnostic programme for the detection of renal involvement in type I diabetes mellitus.

In an effort to establish a reliable programme for the clinical monitoring of renal involvement in patients with type-I diabetes mellitus, we quantified the urinary excretion of immunoglobulin G (IgG), transferrin (Tf), albumin (Alb), alpha 1-microglobulin (alpha 1MG), N-acetyl-beta-D-glucosaminidase (NAG), and total protein in 130 dipstick negative children and young adults with type-I diabetes. Eighty-five sex- and age-matched healthy persons served as a control group for the definition of the upper reference limits (95th centiles; micrograms min-1 1.73 m2): transferrin 1.4; albumin 16.6; total protein 27.1; NAG: 2.0 mU min-1 1.73 m2. Sex-related differences were detected for IgG (men: 3.8; women: 1.7) and alpha 1 MG (men: 6.0; women: 4.0 micrograms min-1 1.73 m2). The urinary excretion of IgG, Tf, alpha 1MG, NAG, and total protein was significantly higher in subjects with diabetes when compared to healthy controls (p < 0.01). Furthermore, 20 patients (15%) showed an elevated excretion of tubular markers (alpha 1MG and NAG), and 3 patients (2%) of at least two glomerular markers (Alb and/or Tf and/or IgG). Additionally, 18 individuals (14%) presented a mixed excretion pattern of both tubular and glomerular markers. These data suggest that the quantitation of both glomerular and tubular proteinuria provides a sensitive and cost-effective instrument for the non-invasive screening for renal involvement in patients with diabetes mellitus.     

Exercise-induced proteinuria in well-trained athletes.

We studied the rate of urinary excretion of albumin, alpha 1-microglobulin (as an indicator of the renal tubular involvement), sodium, potassium, and creatinine in the basal state (overnight urine collection) and after physical exercise (training session) in 10 professional cyclists, to verify whether protein excretion is increased even in well-trained athletes after physical effort. In addition, we wanted to understand whether the origin of exercise-induced proteinuria was glomerular, tubular, or both. Compared with the basal state (overnight collection), exercise significantly (P less than 0.01) increased the excretion rate of albumin (4.2 +/- 2.6 micrograms/min vs 18.1 +/- 10.6 micrograms/min, mean +/- SD), Na, and K, and also the urinary volume. Creatinine output was not affected by exercise. The mean (+/- SD) overnight excretion rate of albumin by athletes was quite similar to that found for 91 healthy nonathletes at rest (4.6 +/- 2.7 micrograms/min). The mean exercise-related excretion of alpha 1-microglobulin by the athletes significantly exceeded the overnight value (6.6 vs 0.3 mg/L, P = 0.037). Our study indicates that (a) albuminuria furnishes the greater contribution to the increase in exercise-induced proteinuria; (b) the exercise proteinuria is both glomerular and tubular in origin, and is reversible; (c) the enhanced protein requirement of athletes may in part be due to the recurrent excretion of proteins in the urine after physical effort.     

Urinary excretion of complement C3d in patients with renal diseases

INTRODUCTION: Complement-mediated tubular injury may play an important role in the progression of renal diseases. C3d is a presumed marker of complement activation. Its precursor C3dg has been detected in the urine of patients with membranous nephropathy. However, little is known of the renal handling of C3d or its excretion in other renal diseases. METHODS: We measured the urinary excretion of albumin, IgG, beta2-microglobulin (beta2m), and of complement C3d in patients with tubulo-interstitial nephritis (TIN; n= 8), in patients with membranous nephropathy (n = 35) and in patients with nonmembranous glomerular diseases (23 nonproliferative and 21 proliferative). Fractional excretions (FE) were calculated using creatinine clearance as marker of GFR. RESULTS: C3d was not measurable in the urine of the healthy controls, but was detectable in seven out of eight of the TIN patients (median excretion 0.11 mU min-1, range 0.006-2.4 mU min-1). In these patients the urinary excretion of beta2m was clearly elevated (median 26.6 micro g min-1, range 1.0-103 micro g min-1). The FE of C3d correlated with the FE of beta2microglobulin (r = 0.83, P = 0.01), and their ratio amounted to 0.03 (range 0.003-0.06), a value in agreement with the expected sieving coefficient. Urine C3d was detectable in all but three of the patients with glomerular diseases (median excretion 0.36 mU min-1, range 0.004-7.9 mU min-1); C3d-excretion did not differ between the three subgroups of patients with glomerular diseases. FEC3d correlated with FEIgG (r = 0.88, P < 0.01). The ratio FEC3d/FEbeta2m was 0.78 (range 0.04-9.99). Selected patients with membranous nephropathy were re-analyzed after (partial) remission of proteinuria. Reduction of proteinuria resulted in a decrease of C3d excretion. CONCLUSION: Urinary excretion of C3d is elevated in patients with TIN, most likely as a mere consequence of decreased tubular reabsorption. In patients with glomerular diseases urinary excretion of C3d is increased and related to proteinuria, independent of the underlying glomerular disease. In these patients there is evidence of increased local formation of C3d.     

Classification of renal proteinuria: a simple algorithm.

Total protein, albumin, alpha1-microglobulin, and immunoglobulin G (IgG) were analyzed in 1,622 urine samples without Bence-Jones proteinuria or gross hematuria. There was correlation with the histological picture obtained on renal biopsy in 61 patients. We established 24-h reference intervals for alpha1-microglobulin and IgG on 659 urine samples with total protein and albumin excretion rates below 100 mg/24 h and 30 mg/24 h, respectively, and creatinine clearance above 80 ml/min. The central 95% reference interval was found to be between 4 and 17 mg/24 h for alpha1-microglobulin and between 3 and 8.5 mg/24 h for IgG. In 80 urine samples with albumin excretion rate above 30 mg/24 h and alpha1-microglobulin and IgG within their reference intervals, we analyzed the 95% central interval of the distribution of the IgG/albumin ratios, and it was found to be within 0.01 and 0.20 (0.90 confidence interval: 0.17-0.24). Proteinuria was considered to be of the selective glomerular type if the albumin excretion rate was abnormal and the IgG/albumin ratio was under 0.20, even when the IgG excretion was within a pathological range. For the classification of proteinuria as predominantly tubular, we estimated the alpha1-microglobulin/albumin ratio in 173 urine samples with normal excretion rates of albumin and IgG and pathological excretion of alpha1-microglobulin. The discriminating value of 0.91 (0.90 confidence interval: 0.78-1.08) was accepted in order to define proteinuria of a tubular origin in the presence of a pathological albumin excretion rate. The association between albumin and IgG excretion rates and tubular reabsorption of the alpha1-microglobulin normally filtered by the glomerulus was studied in 33 urine samples from patients with no histologically significant tubulo-interstitial or vascular disease and a serum creatinine concentration below 141 pmol/l. The optimal curve-fitting function between albumin plus IgG and alpha1-microglobulin excretion rates was of the quadratic type (r = 0.927). Mixed proteinuria was considered when both, albumin and alpha1-microglobulin excretion rates were pathological and could not be included in the previously described groups.     

马蹄肾合并肾输尿管肿瘤6例报告并文献复习

目的探讨马蹄肾合并肾输尿管肿瘤的诊断与治疗方法。方法回顾性分析6例马蹄肾并发肾或输尿管肿瘤患者的临床资料,其中马蹄肾并发肾癌3例,马蹄肾并发输尿管癌2例,马蹄肾并发肾盂癌1例。介绍各类患者的临床表现、诊断及治疗方法。结果 3例肾癌患者1例行根治性肾切除术,1例行腹腔镜肾部分切除术,1例放弃治疗。2例输尿管癌1例行肾输尿管全长切除术,1例行输尿管肿瘤切除术。1例肾盂癌患者行肾输尿管全长切除术。手术过程均顺利,术后患者恢复良好,无外科并发症。结论马蹄肾合并肾输尿管肿瘤临床罕见,手术治疗是首选治疗方案。术前通过影像学评估血管及集合系统变异,术中对峡部的妥善处理是手术成功的关键。     

排尿性膀胱尿道造影筛查儿童原发性膀胱输尿管反流的意义

目的探讨排尿性膀胱尿道造影(micturating cystourethrography,MCU)筛查儿童原发性膀胱输尿管反流(vesi-coureteric reflux,VUR)的意义。方法选择40例经99Tcm-二巯基丁二酸(DMSA)显像后肾脏放射性摄取缺损或减少的尿路感染(urinary tract infection,UTI)患儿行MCU检查,依据国际反流性肾病协会提出的VUR分级标准评价MCU诊断结果。结果 40例MCU检查诊断原发性VUR 16例,检出率为40.0%,其中双侧9例,单侧7例;男8例,女8例;年龄<1岁13例。MCU检查共检出VUR 25个肾输尿管单位,其中Ⅱ级反流2支(8.0%),Ⅲ级反流5支(20.0%),Ⅳ级反流12支(48.0%),Ⅴ级反流6支(24.0%)。结论对UTI患儿进行规范的MCU检查可为原发性VUR诊断和治疗提供客观依据。     

Ultrasound diagnostics of upper urinary tract calculi

The review is dedicated to ultrasonography of the upper urinary tract in patients with nephrolithiasis. Ultrasonographic semiotics of urolithiasis, the ability of unlrasonography to detect nephrolithiasis, and methods of the optimization of these diagnostic techniques in patients with upper urinary tract calculi are covered. The author discusses difficulties that may be faced while differentiating between nephrolithiasis and such conditions as spongious kidney, nephrocalcinosis, calcification of renal papillae, cysts, tumors, and vascular walls, as well as other kinds of renal calcification, associated with ultrasonographic acoustic path phenomenon. The advantages and disadvantages of ultrasonography in cases of X-ray urolithiasis are evaluated in the paper. The article describes hardships in ultrasound visualization of ureteral calculi causing acute upper urinary tract obstruction, and the ways of getting over them.