Ultrasonic kidney size measurement. 2. In normal adolescents

Ultrasonography of both kidneys was performed, on 231 male and 220 females normal junior and senior high school age adolescents. 12 and 20 years. Kidneys grew in correlation with the age, height and body weight. 1) Relationship between the kidney length and the age was y (mm) = 1.747x + 67,663 with 0.489 correlation coefficient and less than 1% risk rate in males, and y (mm) = 1.550x + 76,719 with 0.374 correlation coefficient and less than 1% risk rate in females. 2) Relationship between the kidney length and the height was y (mm) V 0.305x + 43.852 with 0.360 correlation coefficient and less than 1% risk rate in males, and y (mm) = 0.589x + 9.042 with 0.367 correlation coefficient and less than 1% risk rate in females. 3) Relationship between the kidney length and the body weight was y (mm) = 0.290x + 78.258 with 0.373 correlation coefficient and less than 1% risk rate in males, and y (mm) = 0.490x + 76,286 with 0.450 correlation coefficient and less than 1% risk rate in females. No difference the right and left kidney length was recognized in either sex. The growth of female kidneys was faster than that of male kidneys between the ages of 14-17. No difference was observed in length of the right or left kidney or sex with the age group of 18 or over.     

Ultrasonic kidney size measurement. 1. In infants and children

Ultrasonography in a sector scanner at real time was performed on the normal kidneys of 126 males and 101 females up to 12 years of age including infants. The growth of the kidneys was well correlated with the age, height and body weight, but the following findings of the kidney length were obtained when the male and female kidneys were measured in a comprehensive manner. 1) y (mm) = 2.987 X age + 55.029 with 0.864 correlation coefficient and less than 1% risk rate showed a positive correlation with the age. 2) y (mm) = 0.407 X height + 28.045 with 0.879 correlation coefficient and less than 1% risk rate showed a positive correlation with the height. 3) y (mm) = 0.949 X body weight + 50.904 with 0.878 correlation coefficient and less than 1% risk rate showed a positive correlation with the body weight. No difference was recognized between both sexes and the right and left kidneys of infants and school students in their kidney length and thickness.     

Impaired kidney growth in low-birth-weight children: distinct effects of maturity and weight for gestational age

BACKGROUND: Low birth weight is an important risk factor for hypertension and unfavorable prognoses of a number of renal diseases. It is also associated with reduced kidney size and nephron number. A differentiation between the effects of low birth weight versus being born premature or small for gestational age has, however, not been addressed. METHODS: The influence of weight for gestational age (percentage deviation from expected mean), gestational age, birth weight, and early diet on kidney growth was studied in 178 children born pre- or postmature and/or small or large for gestational age, comparing them to 717 mature children, birth weight appropriate for gestational age. Kidney size was determined by bilateral ultrasonography measuring length, width and depth, using the equation of an ellipsoid for volume calculation. The examinations were performed at 0, 3, and 18 months of age together with measurements of body weight, height, and skinfold thickness. RESULTS: Weight for gestational age had a significant, positive effect on combined kidney volume at all three ages (0 months, P < 0.001; 3 months, P < 0.001; and 18 months, P < 0.001). A slight catch-up growth in kidney size was seen in the most growth-retarded infants (<10th percentile) between 0 and 18 months of age (mean Deltaz score(0-18 mo)=+0.22 SD) (P= 0.037). Premature children had smaller kidneys compared to mature at all ages (0 months, P= 0.001; 3 months, P= 0.007; and 18 months, P= 0.042), without any significant catch-up with age. Relative kidney volume was inversely correlated with weight for gestational age at birth (P= 0.007) but positively at 18 months (P= 0.008). Relative kidney growth 0 to 18 months was positively correlated to weight for gestational age (P= 0.013). Low birth weight was associated with impaired relative kidney growth in response to formula feeding. CONCLUSION: Being small for gestational age is associated with small kidneys at birth and impaired kidney growth in early childhood. The present data suggest that intrauterine growth has a regulatory influence on nephron formation and renal function in humans reaching beyond the neonatal period.     

Analysis of kidney volume growth during the fetal period in humans

Summary The growth of fetal kidney volume was studied in 290 specimens taken from 145 fresh human fetuses (85 males and 60 females) with gestational age ranging from 13 to 36 weeks postconception (WPC). Normative equations and curves of the growth of renal volume were obtained for male and female fetuses and for the whole sample in the second trimester (13–24 WPC) and in the third trimester (25–36 WPC) of gestation. There was no difference between the growth in volume of the right and left kidneys. Fetal kidney volume increases with a more intense rhythm in the early fetal period (13–24 WPC). During the second trimester, there was no difference between the values for renal volume of male and female fetuses. In the third trimester, male fetuses had renal volumes significantly greater than the female fetuses. The normative parameters of renal volume could have practical applications in detection and monitoring of renal anomalies in fetal and perinatal urology.Supported by grants 302, 369/86.4/BM-FV from the National Conucil of Scientific and Technological Development (CNPq, Brazil) and Grant E.29/170.787/89 from the Rio de Janeiro Foundation for Research Support (FAPERJ).     

Prenatal programming of adult hypertension in the rat

BACKGROUND: Epidemiological studies have suggested that low birthweight is a risk factor for the development of essential hypertension in adulthood, but the mechanism is unknown. METHODS: A rat model of intrauterine growth retardation was employed. Pregnant Sprague-Dawley rats were kept on 6% protein or on control isocaloric 20% protein diet from gestational day 12 until term. Systolic blood pressures of the offspring were monitored by the tail cuff method. Apoptosis was determined by the TUNEL method, cell proliferation by anti-Ki67 antibody, and the total number of glomeruli by the maceration method. Results are mean +/- SD. RESULTS: The kidney and body sizes of the offspring from the low-protein pregnancies (LP) were proportionately decreased at birth. Full catch-up growth occurred during the first two weeks of life. The kidneys were normal by standard histology but exhibited increased apoptosis without increased cell proliferation at eight weeks of age. The total number of glomeruli per kidney was decreased by 28% in males (P < 0.001) and by 29% in females (P < 0.01). By eight weeks of age, both male and female LP had systolic blood pressures that were 20 to 25 mm Hg higher than those of control animals (P < 0.001), and their 18-month survival was significantly decreased (44 vs. 93%, P < 0.01). During the prehypertensive stage, at four weeks of age, PRA in LP was low (1.7 +/- 1.4 vs. 19.7 +/- 5.5 ng/mL/hour in males, P < 0.0001; 4.9 +/- 2.2 vs. 14.9 +/- 7.2 ng/mL/hour in females, P < 0.0005), and aldosterone was high (93 +/- 15 vs. 54 +/- 27 pg/mL in males, P < 0. 005; 93 +/- 20 vs. 48 +/- 20 pg/mL in females, P < 0.0001). Smaller but significant differences persisted at eight weeks of age. CONCLUSIONS: Adult blood pressure profile is susceptible to prenatal programming by maternal low-protein diet in the rat. The mechanism may involve an altered renin-aldosterone axis and a deficit in total nephron number.     

Effect of body size and malnutrition on renal size in childhood

SUMMARY: Malnutrition is associated with multi-organ manifestations including urinary concentrating defects. the purpose of our study was to prospectively determine the effect of body size and malnutrition on kidney size in children. the length and width of both kidneys were assessed in 525 children with no renal disease (289 male: 236 female; age: newborn–12 years) by real time ultrasonography. the nutritional status was assessed using the Indian Academy of Pediatrics classification, where the expected weight (EW) for age is the 50th percentile for Harvard statistics. Thus, Grade 0: 80–100% of EW; Grade I: 70–80% of EW; Grade II: 60–70% of EW; Grade III: 50–60% of EW; Grade IV: <50% of EW. There was no difference in renal size between males and females, or between right and left kidneys. the relationship between kidney area and age and grade of malnutrition was as follows: kidney area (mm²) = 13.74 age (months)—110.9 grade + 1265 ( P < 0.001). the partial r for grade and age were—0.318 ( P < 0.001) and 0.849 ( P < 0.001), respectively. Normal Indian children (Grade 0) had smaller kidneys than those obtained in age matched children in the Western world. We conclude that severe malnutrition (Grade IV) reduces kidney size independent of age. Furthermore, we attribute the smaller kidney size in normal (grade 0) children, to the smaller body habitus of Indian children. Age based data alone, which are widely used currently to determine if kidney size is appropriate, may not be sufficient in geographic regions where malnutrition is prevalent and/or the growth curves of the population vary from Western derived standards.     

Renal length and inulin clearance in the radiologically normal single kidney

Compensatory hypertrophy of a single functioning kidney is well described and has been shown to occur in utero. The long-term effects of hypertrophy and hyperfiltration in this situation are unknown. This study defined the growth parameters for single kidneys during childhood and correlated them with inulin clearance. Patients were those who had a radiologically "normal" single kidney, where the contralateral kidney was known to be non-functioning from infancy. Data were obtained from 74 children (40 boys and 34 girls) drawn from a registry of cases with a single kidney, and in whom simultaneous measurements of inulin clearance and renal length had been made at around 5, 10, and 16 years of age. Renal length was taken as the maximal bipolar measurement using real-time ultrasound scan. Inulin clearance was by continuous infusion technique. Nomograms for single kidney growth were determined against age, height, weight, and body surface area. Renal growth was correlated with inulin clearance. Renal length was found to correlate best with body surface area (r=0.85, P<0.001), but this was not significantly superior to correlations with age, height, or weight separately. Inulin clearance per body surface area correlated positively with standardized renal length, i.e., Z score for renal length normalized for body surface area (r=0.53, P<0.001). The larger kidneys have a higher glomerular filtration rate. Provided that the nephron number in the single kidney is similar to that in a paired kidney, single kidneys are hypertrophied and the single nephron glomerular filtration rate is likely to be abnormally high in these children.     

Kidney growth in small-for-gestational-age infants: Evidence of early accelerated renal growth.

BACKGROUND: Very few data are available on longitudinal renal growth in small for gestational age (SGA) infants born at term. The aim of this prospective study was to estimate comparatively the renal growth in SGA infants and in infants born appropriate for gestational age (AGA) during the first 2 years of life. METHODS: The study comprised groups of SGA and AGA infants with a gestational age (GA) of 36-41 weeks. The SGA group was classified into two subgroups of symmetrical and asymmetrical neonates according to the ponderal index. Serial renal ultrasonography (US) was performed at the ages of 41 weeks corrected age [GA (in weeks) plus age after birth (in weeks)] and at 3, 6, 12 and 24 months of chronological age and kidney length (KL) was related to other anthropometric indices. RESULTS: A total of 312 infants participated in the study out of which 197 were SGA, and a total number of 802 measurements were performed. The symmetrical SGA infants and, to a lesser degree, the asymmetrical SGA infants had smaller kidneys at birth compared with the AGA infants (P < 0.0001 and P < 0.001, respectively). The symmetrical SGA infants had a lower body weight (BW) (P < 0.001, P < 0.01) and crown-heel length (CHL) (P < 0.01, P < 0.05) than controls at the ages of 12 and 24 months of chronological age. The asymmetrical SGA infants had a lower BW (P < 0.01, P < 0.05) than controls at the ages of 12 and 24 months of chronological age. On the contrary, the KL in both SGA groups was not different from that of the AGA infants after the 41st week of corrected age and up to the 2nd year of life. CONCLUSION: SGA term infants had shorter KL at birth compared with AGA infants but a similar length from the 3rd to the 24th month of life. Early catch-up kidney growth was observed in both SGA groups and is more prominent in the symmetrical SGA infants. This observation may represent either an accelerated renal maturation process or early compensatory kidney hypertrophy in this group of infants.     

Use of marginal organs from non-heart-beating cadaveric kidney donors.

BACKGROUND: The severe shortage of cadaver donor kidneys for transplantation has prompted many centers to utilize older donor kidneys, which have been associated with lower graft survival rates. The aim of the present study was to examine the availability and feasibility of considering kidneys from donors over the age of 60. METHOD: We studied 252 cadaveric renal transplant recipients (156 males, 96 females) who received kidneys from uncontrolled non-heart-beating donors between 1987 and 1997. We performed in situ cooling with especially designed double-balloon catheters to minimize warm ischemic kidney damage. Recipients were classified according to donor age (age 60), and we examined graft survival rates. All patients were followed for a minimum of 1 year after transplantation. RESULTS: Graft survival rates for recipients of kidneys from the older donor group at 1, 5, and 10 years after transplantation were 77%, 37%, and 30%, respectively. Corresponding values for the younger donor kidney recipients were 87%, 64%, and 47%, respectively (P=0.0011). Improved survival rates were noted when older kidneys were used for lighter weight recipients (<54 kg). No other significant factors impacted on older donor graft survival rates. CONCLUSION: Older donor kidneys are associated with poorer graft survival rates. However, kidney transplants from older donors can be quite effective in lighter weight recipients (<54 kg).     

Evidence for retarded kidney growth in sudden infant death syndrome

The aim of the study was to compare the growth rate of the kidneys of infants who died of sudden infant death syndrome (SIDS) and control babies under 1 year; 227 infants who died in St. Petersburg from 1983 to 1990 and who met the criteria for SIDS were included in the study; 138 infants who died suddenly of respiratory infections within the same period constituted a control group. The infants did not have signs of dehydration, malformations, tumours or intrauterine infections. Morphologically the kidneys were intact. Factors which might influence the weight of the kidneys at the time of death were: the cause of death (whether SIDS or not), gender, gestational age, weight, length and ponderal index at birth, age, weight and length at death. Stepwise (forward) linear regression analysis identified three variables which in combination most accurately and independently influenced the predicted weight of the kidneys. These were the cause of death, gender and weight at the time of death. The weight of the kidneys increased by 6.0 g for each increase in total body weight of 1,000 g [95% confidence interval (CI) 5.0 – 7.0 g], in boys the kidney weight was 3.3 g (95% CI 1.6 – 5.0 g) higher than in girls and in the SIDS babies kidney weight was 2.5 g (95% CI 0.8 – 4.2 g) less than controls. Delayed kidney growth may be an indicator of increased risk of SIDS in infants under 1 year and may contribute in some cases. Received May 24, 1995; received in revised form and accepted January 31, 1996     

Segment-specific c-ErbB2 expression in human autosomal recessive polycystic kidney disease

c-ErbB2 (also referred to as Neu or HER2), a transmembrane glycoprotein with intrinsic tyrosine kinase activity, is structurally related to epidermal growth factor receptor (EGFR) and forms active heterodimers with EGFR as well as other members of the EGFR family. c-ErbB2 is reported to mediate differentiation and proliferation in epithelial cells and is expressed in a tissue-specific and developmental stage-specific manner. Given the role of EGFR in cystic renal epithelial hyperplasia and the immature phenotype of cystic renal epithelial cells, the segment-specific expression pattern of c-ErbB2 in human autosomal recessive polycystic kidney disease (ARPKD) was examined in nine ARPKD kidney specimens ranging from gestational age 17 wk through postnatal age 4 wk. c-ErbB2 staining of human ARPKD samples showed increased expression with increasing gestational age compared with normal human fetal and postnatal kidneys. This increased c-ErbB2 expression was primarily localized to the apical surfaces of cystic collecting tubule cells, similar to the pattern of EGFR expression, and paralleled collecting tubular cyst formation and growth.     

Twenty-year follow-up of acquired renal cystic disease

AIMS: Since 1979 the diseased kidneys of 96 patients on replacement therapy with chronic renal failure due to chronic glomerulonephritis have been followed to investigate the development of acquired cysts and tumors. This is a report of the 20-year follow-up. MATERIALS AND METHODS: Ninety-six patients were followed using periodic CT scan and were divided into hemodialysis, renal transplantation, bilateral nephrectomy and deceased groups during the follow-up. In the hemodialysis group, 36 patients (19 males, 17 females) were followed for 20 years. RESULTS: Kidney volumes which were 57.8 (1.51) (geometric mean (geometric SD)) ml at start of the follow-up had become 185.3 (2.03) ml 20 years later in males, and in females, 57.3 (1.64) ml had become 99.7 (2.36) ml. The increased rate was 3.2 (2.06) fold in males and 1.7 (2.57) fold in females. This enlargement of the kidneys was due to acquired cysts. Kidney volumes at the 20-year follow-up had increased more significantly than those at the 15-year follow-up in males; however, kidney volumes at the 20-year follow-up had not changed in females, if compared with data at the 15-year follow-up. Kidney volumes in males at 20-year follow-up were significantly larger than those in females (p = 0.0232). Males with more than 3.2-fold in kidney volume increase at the 20-year follow-up were under the age of 40 at entry into this study (p = 0.0055), although the correlation between the degree of kidney volume increase and age was not significant (p = 0.0910). Kidney volumes in the transplantation group remained small. There was no new renal cell carcinoma development after 15-year follow-up except for the local recurrence of a previous operated case. Although 7 of 44 patients died during the past 20 years due to malignancy, no patient died of renal cell carcinoma because of early detection and treatment. One patient died of retroperitoneal bleeding, which is a complication of acquired renal cystic disease. CONCLUSION: Male preponderance of acquired cysts was maintained at the 20-year follow-up. There was a tendency for the rate of increase in acquired renal cystic disease to be larger in young males. No one died of renal cell carcinoma, although the incidence of renal cell carcinoma was high.     

Sequential analysis of kidney stone formation in the Aprt knockout mouse

BACKGROUND: We have previously shown that, as in human adenine phosphoribosyltransferase (APRT) deficiency, Aprt knockout mice form 2,8-dihydroxyadenine (DHA) renal stones. The disease develops earlier and is more severe in male than in female mice. To examine the biological bases for these differences, the area occupied by DHA crystals was quantified in kidney sections from male and female mice (strain 129) aged one day to eight months and this parameter was correlated with changes in renal histopathology. Aprt heterozygous and wild-type mice were used as controls. METHODS: Following anesthesia, the left kidney was removed and immediately frozen in dry ice. Unstained cryosections were examined by polarized light to determine total area of birefringent particles. The right kidney was perfused and embedded in plastic, and stained sections were viewed by light microscopy to examine the histopathology and to determine the location of the birefringent particles. A pathological score was assigned to the histological findings. The scores from the right kidney were compared with crystal/particle area in the left kidney, and the data were analyzed using two-way analysis of variance. The chemical composition of the particles was determined by x-ray diffraction analysis. Several stone fragments from the bladder were also examined by scanning electron microscopy (SEM). RESULTS: Crystals were detected in kidney sections from one- to two-day-old Aprt knockout mice. The crystal burden remained low in both sexes throughout the study except in males at the 120- to 240-day period. Furthermore, there was a substantial degree of renal pathology, primarily seen as interstitial fibrosis, in those males with a very high level of stone formation. The crystalline material was identified as 6-amino-2,8(3,9)-purine dione, a tautomeric form of DHA. SEM indicated that the crystals were spherical, with a diameter of 10 to 20 microm. Tissue staining and fixation procedures dramatically reduced the amount of birefringent material in kidney sections. Aprt heterozygotes of both sexes had low levels of crystalline material in the kidneys and no pathology. Birefringent material or pathological changes were not seen in kidneys from wild-type mice. CONCLUSIONS: Both male and female Aprt knockout mice accumulate DHA. However, the area occupied by DHA crystals was significantly greater in 120- to 240-day-old males compared with the females of similar age. Also, substantial renal pathology was detected in kidneys of male mice that had very high levels of stone material.     

The Role of Angiotensin II Receptor 1 (AT1) Blockade in Cisplatin-Induced Nephrotoxicity in Rats: Gender-Related Differences

It is documented that chronic renal diseases are gender related. The protective role of angiotensin II receptor 1 (AT1) blocker losartan against cisplatin (CP)-induced nephrotoxicity was reported in males, but the role of gender is not well known. Six groups of Wistar rats were studied. Rats were divided into two groups of males and females to receive losartan for 9 days plus a single dose of CP (7 mg/kg) at day 3. Two positive control groups of males and females received the same regimen, except that they received saline instead of losartan. The negative control groups received saline instead of CP at day 3 and also saline instead of losartan. The blood samples were obtained, and the kidneys underwent histopathological investigations. All the CP-treated animals lost weight, but losartan promoted weight loss in females (p < 0.05). Coadministration of losartan and CP in females, but not in males, significantly increased the serum levels of blood urea nitrogen and creatinine when compared with the negative and positive control groups (p < 0.05). No significant differences were observed in serum levels of total proteins, magnesium, and nitrite between the groups. Administration of CP increased the kidney tissue damage score (KTDS) and normalized kidney weight (p < 0.05). However, in the presence of AT1 blockade, the KTDS (nonsignificantly) and normalized kidney weight (significantly, p < 0.05) increased in the CP-treated females. Such an observation was not seen in males. Losartan may prevent CP-induced nephrotoxicity in males, but it promotes the CP-induced damage in females, which may be related to the renin-angiotensin system receptors in the kidneys.     

Endotoxin and nanobacteria in polycystic kidney disease

BACKGROUND: Microbes have been suspected as provocateurs of polycystic kidney disease (PKD), but attempts to isolate viable organisms have failed. Bacterial endotoxin is the most often reported microbial product found in PKD fluids. We assessed potential microbial origins of endotoxin in cyst fluids from 13 PKD patients and urines of PKD and control individuals. METHODS: Fluids were probed for endotoxin and nanobacteria, a new bacterium, by the differential Limulus Amebocyte Lysate assay (dLAL), genus-specific antilipopolysaccharide (LPS) antibodies, monoclonal antibodies to nanobacteria, and hyperimmune serum to Bartonella henselae (HS-Bh). Selected specimens were also assessed by transmission electron microscopy (TEM) and nanobacterial culture methods. RESULTS: LPS or its antigenic metabolites were found in more than 75% of cyst fluids tested. Nanobacteria were cultured from 11 of 13 PKD kidneys, visualized in 8 of 8 kidneys by TEM, and immunodetected in all 13 PKD kidneys. By immunodetection, nanobacterial antigens were found in urine from 7 of 7 PKD males, 1 of 7 PKD females, 3 of 10 normal males, and 1 of 10 normal females. "Nanobacterium sanguineum" was dLAL positive and cross-reactive with antichlamydial LPS and HS-Bh. Some cyst fluids were also positive for LPS antigens from Escherichia coli, Bacteroides fragilis and/or Chlamydia, and HS-Bh, as were liver cyst fluids from one patient. Tetracycline and citrate inhibited nanobacterial growth in vitro. CONCLUSION: Nanobacteria or its antigens were present in PKD kidney, liver, and urine. The identification of candidate microbial pathogens is the first step in ascertaining their contribution, if any, to human disease.     

Nomogram of fetal renal growth expressed in length and parenchymal area derived from ultrasound images

PURPOSE: We constructed nomograms of fetal renal length and parenchymal area derived from ultrasound images to develop a standard for normal fetal renal growth. MATERIALS AND METHODS: Longitudinal and transverse ultrasound renal images from 216 normal fetuses (16 to 41 weeks of gestation) were evaluated to construct growth charts. We measured the parenchymal area as well as the longitudinal and transverse lengths of each kidney using computer software for image analysis. Data were separately plotted as a mean +/- 2 SD determined by polynomial regression analysis. RESULTS: Nomograms for a renal growth chart were constructed independently for the right and left fetal kidneys. No statistically significant difference was noted between the right and left renal measurements. The polynomial regression equations for the left renal longitudinal length and parenchymal area, respectively, were y = -0.0002x(3) + 0.0139x(2) - 0.2162 x 2.3929 (r(2) = 0.9842), and y = -0.0009x(3) + 0.0724x(2) - 1.5643 x 11.68 (r(2) = 0.9779). The longitudinal and transverse fetal renal growth curves displayed significant growth associated with gestational age (p <0.001). Our data on left longitudinal renal length exhibited an intermediate level compared to 2 published Western growth charts. However, statistical comparisons revealed the differences were partially, but not universally, significant. CONCLUSIONS: We present our nomogram of fetal renal growth expressed in length and parenchymal area. To our knowledge this is the first report of a fetal renal growth chart in Asia that includes the parenchymal area. This nomogram may serve as a valuable tool for evaluation of fetal renal growth.     

Ultrasonographic study on kidneys in patients with chronic renal failure. Part II. Acquired cystic disease of the kidneys

Ultrasonic examination of the kidney was performed on 280 patients undergoing chronic dialysis. Acquired cystic disease of the kidney (ACDK) was detected in 107 of 529 kidneys (20.2%). This paper presents an analysis of ultrasonotomograms of ACDK. Ultrasonic measurement of the size of ACDK was 72.5 +/- 15.2 mm in length and 41.7 +/- 9.8 mm in thickness. The size of ACDK was significantly greater than that of contracted kidneys by ultrasonographic diagnosis. With regard to sex distinction the length and thickness of ACDK were significantly greater in males than in females. As for laboratory data, patients with ACDK showed significantly higher values of red blood cell count, hematocrit and serum creatinine concentration compared with contracted kidneys. Prolongation of the dialysis peirod increased the incidence of ACDK. The size of ACDK showed a tendency to increase with duration of dialysis. However, no correlation was noted statistically between the incidence of ACDK and duration of dialysis and between the size of ACDK and duration of dialysis. There was a significantly lower incidence of ACDK in patients with diabetic nephropathy than those with chronic glomerulonephritis. A sonographic feature of ACDK is irregularity of the renal contour because of cystic transformation. Renal imaging, identification of the corticomedullary border, identification of the central echoes and increased parenchymal echogenicity were similar to other dialyzed kidneys. The main complications of ACDK are hemorrhage and tumor formation. We observed two retroperitoneal hematomas and one renal cell carcinoma developed within two years after this examination. The incidence of complications of ACDK was 5.1 per cent. We believe that patients with ACDK should be watched carefully by regular ultrasonic examination for early diagnosis and treatment of these complications.     

超声评价健康人群肾脏大小及其影响因素

目的探讨健康成年人双侧肾脏各径线与年龄、性别、身高、体质量及体质量指数(BMI)的相关性。方法对1036名健康体检者行双侧肾脏超声检查,测量双侧肾脏长径、横径及前后径,并分析其相关影响因素。结果男性双侧肾脏长径、横径及前后径均大于女性;单因素分析显示,除右肾长径与年龄、身高、体质量及BMI无相关性、左肾前后径与年龄无相关性外,其他各条径线均与年龄、身高、体重及BMI有相关性;多元分析中,年龄及性别是影响肾脏各径线的主要因素。结论多种因素影响肾脏各径线长度;右肾长径所受影响因素较少,可作为主要参考指标。