Aims of the study were to assess the length of morphologically normal kidneys ultrasonically and to build models to predict the renal lengths with the view of preparing prospective context-specific normograms. Accurate prediction of reference ranges of renal lengths facilitates clinical decision making.
But currently a single renal-length-reference chart is use for both kidneys; which is solely based on the age of the child without adjusting for anthropometrics. The objective of the study is to assess the length of morphologically-normal kidneys ultrasonically and to build models to predict the renal lengths of children presenting at the Radiology Department of Lady Ridgeway Hospital for Children.
A descriptive cross sectional study among 424 children; with 233 males and 191 females at the study setting. Study population included children undergoing abdominal ultrasound scans for indications not related to renal disease. But children with a family history; but of renal diseases or with morphologically-abnormal kidneys were exclude. Bipolar-lengths of kidneys, gender and anthropometrics were document. But having test for assumptions, Wilcoxon-signed rank test, Mann-Whitney U test and multiple linear regression were used.
The renal lengths
The mean (SD) bipor-length of right and left kidneys were 6.83 (1.43) and 7.05 (1.36) respectively (p < 0.001). Age, height and weight were significantly correlated with the renal lengths (p < 0.05). But 16 months, there was a significant difference between the renal lengths between males and females (P < 0.05). Yet the association with gender was not significant from 17 months and in overall.
However until 16 months, the best linear-regression equation (p < 0.001) for the left kidney was; 3.827 + 0.019(length in centimeters) + 0.141(weight in kilograms) – 0.023(age in months) – 0.347(for male sex). For the right kidney, it was; 3.888 + 0.020(length or height) + 0.121(weight) – 0.037(age) – 0.372 (for male sex).
But the respective R squares were 59.2 and 53.5% with VIF (Variance-Inflation-Factor) ranging from 1.06 to 2.08. From 17 months, best equation for left kidney (p < 0.001) was; 5.651+ 0.022(age) + 0.01(BMI). For right kidney it was; 5.336 + 0.022(age) + 0.012(BMI). The R squares were 62.5 and 66.1% with VIF being 1.
Best equation for left and right kidney
The established models explain more variability for children above 17 months. Both renal lengths are affected significant by the body’s’ anthropometric parameters. For each kidney, separate normograms of renal lengths which are local-context-specific must be prepared. Further research must promote.
The lengths of the left and right kidneys are different. Both renal lengths are affect significant by the body’s’ anthropometric parameters. The percentage of variability explain by the models were higher for “17 months; and above children” than “16 and below” category. Separate normograms of renal lengths which are local-context-specific must be prepare. Further research must be promote to establish more robust models utilizing this evidence as an eye-opener.