Measurement Of Renal Length Research Articles

Kidney/Aorta Ratio for Renal Morphometric Determination in Swine Subjected to Acute Kidney Injury Using an Optimized Surgical Model.

This research aims to establish an experimental surgical model for access to the renal pedicle and kidney and to determine renal length measurement via the kidney/aorta ratio (K/AO) using ultrasound. Fifteen swine underwent ventral median celiotomy with a supraumbilical transverse incision to access the right and left renal pedicles and induce renal ischemia-reperfusion injury (IRR). The kidneys were evaluated using ultrasonography to standardize renal length, aortic diameter, and the K/AO. Assessment was performed at 2 time points: 1 h before and 24 h after the surgery to induce IRR. Blood and urine samples were collected to assess renal function. Histologic evaluation of kidney fragments was also conducted. The proposed abdominal cavity access method proved to be highly efficient for exposing the right and left renal pedicles and inducing IRR. Serum levels of urea, creatinine, calcium, and phosphorus, as well as levels of the urinary protein/urinary creatinine ratio and urinary GGT, did not show significant differences. Acute kidney injury was confirmed through histopathology. The mean lengths of the right and left kidneys were 82.63 and 87.64 mm, respectively. The values of the right and left K/AO were 9.81 and 10.38, respectively. There was no statistically significant difference in the K/AO ratio before and after IRR. The proposed surgical model allowed surgical intervention on the renal pedicles without intra- or postoperative complications. Furthermore, the K/AO could be measured through ultrasonography, establishing a reference for healthy animals.

Correlation of renal length with anthropometric and demographic data in healthy children: A prospective cross sectional study

BackgroundRenal size is an important parameter in the assessment of a child with renal disease. Renal size can be estimated by measuring renal length, renal volume, and cortical volume or thickness. Renal length depends on different factors, which include size, body mass index and gender. Ultrasonography is useful, non-invasive and easily available method for reliably performing the measurement of kidney length. This study was conducted to find out correlation between renal length and age and anthropometric variables in healthy children. This prospective cross sectional study was carried out with the following objectives: (a) To determine the anthropometric variable that correlated best with renal length in healthy children. (b) To develop a nomogram for renal length in healthy children. MethodsFive hundred healthy children were included in this study. Sonographic assessment of renal length was performed using real time mechanical sector scanner with 5 MHz and 8 MHz frequency. The renal length was correlated with somatic parameters like age, weight, height, body surface area and body mass index. Regression equations were derived for each pair of dependent and independent variables. ResultsWe performed the measurement of renal length in 500 healthy children. In our series, renal measuring parameters showed a good correlation with studied body parameters, height having the best correlation. Data from left and right kidneys are shown separately since there was small but statistically significant difference between them. Based on our study, using the height of the child, renal length may be calculated by using following equation: Left renal length (cm) = 0.052 × height (cm) + 1.042, Right renal length (cm) = 0.052 × height (cm) + 0.867. ConclusionsThis study provides values of renal length (mean ± 2SD) in normal Indian children and its correlation with body parameters. Renal length may be easily calculated by derived linear regression equation. Nomograms of renal length with respect to age and height have been formulated. Renal Length was found to correlate best with height of the child.

A Comparability of Renal Length and Volume Measurements in MRI and Ultrasound in Children.

Introduction: Despite the significant increase in use of magnetic resonance imaging (MRI) in children, there is still a lack of normal reference values of renal size in this method and reference values are being interpolated from the ultrasound (US) studies. The study provides comparative analysis of agreement in renal length and volume measurements between MRI and ultrasound.Materials and Methods: Ninety-three children with a mean age of 8.0 ± 6.0 years, who had undergone both renal US and MRI exams, were included in the study. Participants were divided into three subgroups; each kidney was considered separately.Group 1 included 106 kidneys without any anomalies. Group 2 comprised 48 kidneys with a dilated collecting system. Group 3 included 32 kidneys with a duplicated collecting system. Measurements were taken in three dimensions, and renal volume was calculated from the ellipsoid formula.Results: We found no significant difference between US and MRI measurements in Group 1 and Group 2. In Group 3, the difference between measurements in both imaging methods was significant. The mean difference varied from 0.05% in Group 1, 2.95% in Group 2, to 4.99% in Group 3.Conclusion: The US and MRI are comparable methods in renal size measurements. The interpolation of sonographic renal length and volume reference values to the MRI in the pediatric population is justified, as there is a strong agreement between both methods. Both methods can be used interchangeably for following up of the renal size changes in the pediatric population.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum.

The AIUM Practice Parameter for the Performance of an Ultrasound Examination of the Abdomen and/or Retroperitoneum.

What are the Optimal Renal Ultrasound Parameters for Detecting Small Kidney in Young Children?

IntroductionRecent guidelines do not recommend routine screening of vesicoureteral reflux after a first febrile urinary tract infection in children without abnormal findings on ultrasound or atypical/recurrent urinary tract infection. Currently, there are no clear ultrasonographic parameters for detecting abnormalities in renal size, especially in young children. The aim of the present study was to determine an optimal cutoff value for detecting small kidney in children without apparent congenital anomalies except vesicoureteral reflux by retrospective chart review.Patients and MethodsChildren aged ≤3 years who had undergone nuclear renal scans and ultrasound were enrolled. Small kidney was defined as split renal function of <40%. Optimal cutoff values of various ultrasonographic parameters for detecting small kidney were calculated.ResultsOf the 69 children included in the present study, small kidney was identified in 20. There was a significant difference in renal size between each kidney in patients with small kidney, whereas there was no significant difference in those without small kidney. With a ratio of estimated renal area of 74.26%, maximum area under the curve with the highest sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate were obtained. In addition, simple measurement of renal length with a cutoff of 4.97 cm showed high specificity comparable with estimated renal area.ConclusionSmall kidney may be screened by two-dimensional measurement on ultrasonographic examination, even in young children. With the cutoff described, risk stratification or an individualized approach may be possible.

Computed Tomographic Assessment of Renal Volume and Its Associative Factors Among Adults.

Knowledge of normal renal volume is a vital parameter for clinical assessment of renal diseases because renal size is altered by various medical conditions. Variations in renal dimension in different populations and it's relation to individual's body parameters are evident. Different studies have recommended the need for measurement of renal dimension for specific population. This study assesses normal range of renal volume in the study population and measures their correlation with individual's body parameters. This descriptive study was done in 261 adults. After renal length measurement on reformatted coronal images, renal width and renal thickness on axil images, renal volume was calculated by ellipsoidal formula. Descriptive statistics and parametric tests were used to evaluate the association between renal volume and different parameters. This study showed a significant difference in mean renal volume between male (right and left mean renal volume 120.52 ± 26.84 cm3 and 121.00 ± 27.23 cm3 respectively) and female (right and left mean renal volume 110.11 ± 21.79 cm3 and 111.15 ± 22.34 cm3 respectively) on each side. Similarly, a significant positive correlation was found between renal volume and body height, body weight and BMI of participant for both kidneys however a significant negative correlation was observed between renal volume and age 40 years and above for both kidneys. Conclusions: This study provides morphometric data regarding normal kidneys and concludes that male renal volume is more than female and renal volume is correlated to individual's body parameters.

Measurement of Kidneys in Sudanese Children up to Five Years Old Using Ultrasonography: Age as Predictor for Renal Length Measurement

Measurement of Kidneys in Sudanese Children up to Five Years Old Using Ultrasonography: Age as Predictor for Renal Length Measurement

The relationship between body mass index and renal length in obese children

Obesity in the pediatric population is a severe public health problem and is associated with various comorbidities. Renal length is an important clinical parameter for the diagnosis and follow-up of renal diseases. The aim of this study was to determine the relationship between renal length (measured ultrasonographically) and body mass index (BMI) in obese children, and to develop nomograms for renal length according to BMI. Renal ultrasound was performed in 368 children without renal disease. Each child's age, gender, weight, height, and BMI (kg/m2) were recorded. The children were divided into three groups according to BMI percentiles: obese group: BMI ≥ 95th percentile; overweight group: BMI 85th-94th percentile; normal weight group: BMI 5th-84th percentile. Weight, height, BMI, and right and left renal length differed significantly between the three groups (p = 0.001). There were significant correlations between renal length with age, weight, height, and BMI. Measurement of renal length was independently associated with BMI, age, and height. BMI was used to create renal length nomograms for obese children, based on multiple regression analysis (R2 = 0.32 and p = 0.0001). Mean renal length was highest in the obese group (96.9 ± 13.4mm) and lowest in the normal weight group (88.3 ± 12.9mm). Ultrasonographic measurement of the renal length according to BMI in children can be a useful method in evaluating these children. Smaller-than-normal kidneys can easily remain undiagnosed in obese and overweight children and this nomogram offers an additional method to evaluate the renal size in obese children.

Normal sonographic renal length measurements in an Australian pediatric population.

Reference charts depicting normal growth are important for the sonographic assessment of the pediatric kidney. Limited charts are available for clinical use in an Australian population. To retrospectively collate sonographic renal length measurements in a cohort of low-risk Australian children aged newborn to 16years to produce a reference table and comparison with other published charts. We identified consecutive pediatric patients who were at low risk for renal disease and had renal lengths measured. After exclusions, we included 941 renal lengths (male 490, female 451). We used linear regression to estimate the relationship of renal length with age, gender and side. We calculated percentile values of renal length according to age categories. No statistically significant differences in mean renal length were observed between males and females, or for left and right kidneys. We tabulated reference data and provide them in a reference chart (1-, 2.5-, 5-, 10-, 50-, 90-, 97.5- and 99-percentiles). We calculated new reference ranges for pediatric renal length using a larger cohort than previously published, from a population with diverse ethnicity.

The Incidence and Durability of Compensatory Hypertrophy in Pediatric Patients with Solitary Kidneys

ObjectiveTo evaluate the incidence and durability of compensatory hypertrophy with solitary kidneys in the setting of those with multicystic dysplastic kidney (MCDK) or Wilms tumor (WT) status postnephrectomy. Patients and MethodsWe conducted a retrospective cohort study of patients with MCDK and WT. MCDK patients were verified by sonographic findings prenatally. WT patients entered our study at time of nephrectomy. We compared the natural history of hypertrophy between the 2 cohorts via renal length measurement. We performed linear regression to predict creatinine clearance from renal length after adjusting for age and cohort status (MCDK versus WT). ResultsFifty-two patients (56%) were diagnosed with WT, and 71 patients (44%) with MCDK patients met study criteria with a median age of postnatal ultrasound at 1.6 months (interquartile range 0.5-3.6). The median (IQR) follow-up time was 7.5 years. At the time of nephrectomy, 25/52 (48%) of Wilms patients had contralateral hypertrophy, while at diagnosis 22/71 (31%) of MCDK patients had contralateral hypertrophy, P = .03. Contralateral hypertrophy was a consistent finding throughout follow-up. As renal length increases by 1 cm, glomerular filtration rate increased by 7.8 mL/min/m2 (95% confidence interval 1.8-13.8, P = .01). ConclusionContralateral hypertrophy appears to be a compensatory mechanism for unilateral kidney pathology as demonstrated by MCDK and WT patients. Hypertrophy often occurs at the time of diagnosis and appears to be a permanent finding as children reach their teenage years. Additionally, in nonhydronephrotic kidneys, increases in renal length correlate with improvement in glomerular filtration rate. Overall, the majority of children with solitary kidneys demonstrate compensatory hypertrophy.

AIUM Practice Parameter for the Performance of Point-of-Care Ultrasound Examinations.

AIUM Practice Parameter for the Performance of Point-of-Care Ultrasound Examinations.

Congenital solitary kidney size at birth could predict reduced eGFR levels later in life.

To evaluate the impact of congenital solitary functioning kidney (CSFK) length, measured early in life, on the eGFR levels during the follow-up. We retrospectively selected 162 CSFK patients undergoing, within 60 days of life, renal length (RL) measurement by ultrasound. We divided the population in: Group 1 = RL ≥ 2 standard deviation score (SDS). Group 2 = RL < 2 SDS and showing RL ≥ 2 SDS during the follow-up. Group 3 = RL < 2 SDS and showing RL < 2 SDS during the follow-up. development of eGFR below the range of normality. The median follow-up period of the overall population was 6.2 years (range 2-21.5 years). The cumulative proportion of patients free of primary outcome at 15 years of age was 96.4% in group 1, 64.6% in group 2, and 45.6% in group 3 (p = 0.03). The RL > 2 SDS within 60 days of life was a significant protective factor (hazard ratio = 0.13; 95% C.I. 0.02-0.97) against development of primary outcome. RL ≥ 2 SDS within 60 days of life could identify a population of CSFK with reduced risk of presenting reduced eGFR levels later in life.

Prospective evaluation of kidney displacement during supine mini-percutaneous nephrolithotomy: Incidence, significance, and analysis of predictive factors

Kidney displacement may alter the quality of renal puncture during percutaneous nephrolithotomy (PCNL). The aim of this study was to identify the rate of kidney displacement and parameters associated with kidney displacement in patients who underwent supine mini-PCNL. Data of 98 consecutive patients who underwent mini-PCNL was collected prospectively. The patients were grouped as displacement-positive vs. -negative. The parameters collected were age, gender, body mass index, side of the kidney, punctured calyx, fluoroscopy time to successful puncture and tract dilation, stone-free and complication rates, stone diameter, length of the renal artery, and quantity of peri-renal and abdominal fat. Groups were compared for the above listed parameters and logistic regression analysis was performed to identify factors associated with kidney displacement. There were 34 and 64 patients in the displacement-positive and -negative groups, respectively. Groups were similar for stone-free and complication rates. Fluoroscopy time to puncture and tract dilation were longer in the displacement-positive group. Groups were different for renal artery length and peri-renal fat measurements. In multivariate analysis, lower pole puncture, renal artery length, and peri-renal fat measurement were found to be independent predictors of kidney displacement. Kidney displacement does not alter the success and complication rates, but is associated with longer fluoroscopy times during supine PCNL. In the current study, parameters in preoperative non-contrast computerized tomography (NCCT) associated with kidney displacement were identified. We recommend surgeons evaluate and take into account these parameters during preoperative planning to establish better outcomes and diminish fluoroscopy times.

Clinical significance of renal cortical thickness in patients with chronic kidney disease.

PurposeThe aim of this study was to evaluate the correlations between laboratory findings and ultrasonographic measurements of renal length and cortical thickness in patients receiving follow-up for chronic kidney disease (CKD).MethodsA total of 41 CKD patients (18 males and 23 females; mean age, 65.2 years; range, 42 to 85 years) with a low glomerular filtration rate who did not require renal replacement therapy were included in this prospective study. Patients were followed up with laboratory assays at bimonthly intervals and with ultrasonography performed twice a year. Renal cortical thickness, renal length, and estimated glomerular filtration rate (eGFR) values were compared using the paired-samples t test. Additionally, Pearson correlation analysis was conducted between renal length and cortical thickness measurements and eGFR values to assess kidney function.ResultsAt the beginning of the study and after 24 months, mean eGFR values of the 41 patients were 35.92 mL/min and 28.38 mL/min, respectively. The mean renal length was 91.29 mm at the beginning of the study and 90.24 mm at the end of the study. The mean cortical thickness was 5.76±2.05 mm at the beginning of the study and 5.28±1.99 mm at the end of the study. A statistically significant positive association was found between eGFR and mean renal length (r=0.66, P<0.01) and between eGFR and mean cortical thickness (r=0.85, P<0.01), with the latter being more prominent.ConclusionOur study suggests that ultrasonographic cortical thickness measurements may be an important imaging technique in the follow-up care of patients with CKD.

Analysis of Kidney Ultrasound Dimensions by Body Habitus and Position

Renal dimensions are an important assessment of the genitourinary tract used to evaluate critical aspects of renal growth and development. Understanding the effect of patient position is important to use and interpret these parameters. In this prospective study we determined the effect of patient position and general body habitus on renal length and parenchymal area in children undergoing renal ultrasound. Between October 2010 and January 2011 children underwent renal ultrasound while prone and supine. Bilateral renal length and renal parenchymal area were measured. Pearson and Bland-Altman statistical analyses were used to examine correlations, measurement bias and the degree of agreement between methods. Renal length measurements in both positions were complete for 201 right and 196 left kidneys. Parenchymal area measurements were complete for both kidneys in 177 children. When compared individually, supine and prone measures of renal length and parenchymal area highly correlated on Pearson analysis (greater than 0.96 and greater than 0.89, respectively). When compared by method, Bland-Altman analyses of differences vs means showed greater than 50% variance, representing wide limits of agreement with poor interrelation. Neither persistent systematic bias nor body habitus influenced results. While Pearson analysis showed high correlation for supine and prone renal measurements, Bland-Altman analysis of renal length and parenchymal area demonstrated wide limits of agreement, not allowing interchangeable use of prone and supine measurements. As such, renal ultrasound should specify standardized positions and benchmarks. These results provide guidance to standardize renal ultrasound measurements when renal size is used as an indicator of kidney health.

Comparative Analysis of Maximum Renal Longitudinal Length with Positional Changes on Ultrasound with Multiplanar Reconstructed MR Image in Korean Adults

Renal size is an important parameter used for clinical evaluation of renal growth and renal abnormalities (1). The documentation of symmetric small kidneys supports the diagnosis of progressive chronic renal disease with an irreversible component of scarring. Normal kidney size suggests the possibility of an acute rather than chronic process (2). Accordingly, accurate measurement of renal size can be of importance in the diagnosis and treatment of renal diseases. As the kidneys are not parallel with the craniocaudal direction in the body, in the case of 3D CT or MR imaging techniques, the reconstruction of oblique images that match the long axis of the left or right kidney is necessary for radiologists for accurate measurement of renal length (3). Comparative Analysis of Maximum Renal Longitudinal Length with Positional Changes on Ultrasound with Multiplanar Reconstructed MR Image in Korean Adults 초음파상 자세 변화에 따라 측정한 콩팥 최대장경의 다면재구성 자기공명영상과의 비교분석

Multiplanar Reformations in the Measurement of Renal Length on CT: Is It Plain Which Plane to Use?

The objective of this study was to determine the accuracy of renal measurement on CT in multiple imaging planes. In this study, three board-certified radiologists retrospectively measured 110 kidneys on CT in 55 consecutive patients. Five measurement methods were used: axial, coronal single image, coronal multiimage, sagittal single image, and sagittal multiimage. The coronal database was sent to a postprocessing workstation, and each radiologist performed a maximum renal measurement using a best off-axis plane that was our reference standard. An ANOVA test with repeated measures and posthoc Bonferroni corrected t tests were performed. The mean differences (± standard error) compared with the reference standard method were as follows: axial, 7.7 ± 0.7 mm; coronal single image, 13.1 ± 1.4 mm; coronal multiimage, 6.4 ± 0.8 mm; sagittal single image, 6.4 ± 0.6 mm; and sagittal multiimage, 2.8 ± 0.3 mm. The reference standard measurement was larger (p < 0.001), whereas the coronal single-image measurement (p ≤ 0.006) was smaller than all other methods. The sagittal multiimage (p ≤ 0.005) was statistically significantly different from all other methods. There were no statistically significant differences among the axial, coronal multiimage, and sagittal single-image methods (p ≥ 0.088). The single-image coronal method is the least accurate, with an error of approximately 13 mm. The axial, multiimage coronal, and single-image sagittal methods underestimate renal size by approximately 6-8 mm. Multiimage sagittal is the most accurate method for measuring kidneys with an error of approximately 3 mm.

Correlation of renal volume to renal function and blood pressures in low birth weight children

Background Disruption of nephrogenesis in low birth weight(LBW) infant leads to decreases in nephron number andrenal volume, resulting in renal hyperfunction and eventually,hypertension.Objective To assess for a possible correlation of renal volume torenal function and blood pressures in low birth weight childrenaged 7 -8 years.Methods We conducted a retrospective cohort study on childrenaged 7-8 years in Manado, who were born LBW or n ormalbirth weight (NBW). Renal function was assessed by measuringblood cyctatin-C level while renal volume was determined usingultrasound measurements of renal length x width x thickness(cm3). Ttest was used to compare renal volume and cystatin-Clevels in LBW children to NBW children. Pearson's correlationtest was used to assess the relationship of renal volume to renalfunction and blood pressure in low birth weight children.Results Subjects were 48 LBW and 48 NBW children. Meanrenal volumes were 7 8.28 (SD 7 .96) cm3 in the LBW group and103.68 (SD 12.52) cm3 in the NBW group (P&lt; 0.01). The meancystatin-C levels, as a measure of renal function, were 0.81 (SD0.07) mg/Lin the LBW group and in 0.73 (SD 0.06) mg/Linthe NBW group (P&lt; 0.01). There was no correlation betweenrenal volume and cystatin-C level (r=-0.169; P&gt;0,05) as wellas between renal volume and systolic (r=-0.07, P&gt;0.05) anddias tolic blood pressure (r=-0.123, P&gt;0.05).Conclusion Mean renal volume is lower in the LBW groupthan in the NBW group, but is not correlated to decreased renalfunction or blood pressures.

Small renal size in newborns with spina bifida: possible causes

Previous studies reported that children with neural tube defects, but without any history of intrinsic renal diseases, have small kidneys when compared with age-matched standard renal growth. The aim of this study was to investigate the possible causes of small renal size in children with spina bifida by comparing growth hormone deficiency, physical limitations and hyperhomocysteinemia. The sample included 187 newborns with spina bifida. Renal sizes in the patients were assessed by using maximum measurement of renal length and the measurements were compared by using the Sutherland monogram. According to the results, the sample was divided into two groups--a group of 120 patients with small kidneys (under the third percentile) and a control group of 67 newborns with normal kidney size. Plasma total homocysteine was investigated in mothers and in their children. Serum insulin-like growth factor-1 (IGF-1) levels were measured. Serum IGF-1 levels were normal in both groups. Children and mothers with homocysteine levels >10 μmol/l were more than twice as likely to have small kidneys and to give to birth children with small kidneys, respectively, compared with newborns and mothers with homocysteine levels <10 μmol/l. An inverse correlation was also found between the homocysteine levels of mothers and kidney sizes of children (r = - 0.6109 P ≤ 0.01). It is highly important for mothers with hyperhomocysteinemia to be educated about benefits of folate supplementation in order to reduce the risk of small renal size and lower renal function in children.

645 SONOGRAPHIC ASSESSMENT OF THE EFFECT OF VESICOURETERAL REFLUX AND URINARY TRACT INFECTIONS ON GROWTH OF THE PEDIATRIC SOLITARY KIDNEY

INTRODUCTION AND OBJECTIVES: Many papers have addressed the effect of vesicoureteral reflux (VUR) and urinary tract infections (UTIs) on renal growth. Studies have shown that patients with solitary kidneys, especially those with congenital anomalies of the kidneys and urinary tract are more likely to end up with chronic kidney disease and end stage renal disease. Based on sonographically determined renal length we evaluated the effect of VUR and UTIs on the growth of solitary kidneys. METHODS: We retrospectively reviewed a cohort of 158 patients with the diagnosis of solitary or functionally solitary kidney seen in a pediatric urology practice between 2001 and 2011. Patients between 1 month and 18 years old with at least one ultrasound renal length measurements were included in the study. A total of 751 ultrasounds were included from 42 patients with VUR and 116 without VUR. Based on a linear mixed effects model, we investigated the influence of VUR and UTIs on the renal growth rate for solitary kidneys. Interactive effects between age, VUR and UTI status were also modeled. RESULTS: The VUR subgroup had more ultrasounds on average (p 0.001). The left solitary kidney tended to be larger than the right (p 0.042). Kids with VUR did not have a statistically significant larger number of UTIs (p 0.25). Solitary kidneys started out the same size regardless of VUR status but started to cross as patients aged. A solitary kidney with neither VUR nor UTIs grew 0.49 cm per year, while a solitary kidney with VUR grew 0.40 cm per year (p 0.001) and a solitary kidney with VUR and UTIs grew 0.31 cm per year (p 0.005). CONCLUSIONS: Our analysis shows that solitary kidneys start equal in size but that VUR and UTIs independently cause a statistically significant slower growth rate. The kidneys become relatively smaller over time as compared to those without VUR and UTIs. This suggests that the effect of VUR and UTIs on the growth of the solitary kidneys persists throughout childhood. Further studies are needed to evaluate the mechanism of this effect, whether these patients eventually develop renal insufficiency and whether more aggressive early management would be warranted.