Renal Length Discrepancy on Ultrasound Predicts Abnormal Kidney Scan in Children
Journal of Pediatric Nephrology,
Vol. 13 No. 1 (2025),
12 May 2026
https://doi.org/10.22037/jpn.v13i1.49831
Abstract
Background and Aim: A renal length discrepancy (RLD) of more than 10 mm by ultrasound
(US) is accepted as a potential indicator of an underlying renal pathology. This study aimed to
determine the predictive value of RLD detected by US for identifying abnormal findings on
kidney radioisotope scans, specifically dimercaptosuccinic acid (DMSA) scans, in children.
Methods: The study involved a prospective data analysis of children who underwent renal
US and DMSA scans. The positive and negative predictive values for renal RLD were
calculated for values ranging from 6 to >10 mm.
Results: The left kidney was longer in 51.4% of cases, whereas the right kidney was longer in
35.7%; their lengths were equal in 12.9%. The results indicated that a specific degree of RLD
in the US could predict abnormalities on DMSA scans with varying degrees of accuracy,
depending on the age group. The cutoff ultrasound RLDs that resulted in the best specificity
and sensitivity for an abnormality on DMSA scan were ≥5 mm in children whose right kidney
was longer than the left, and ≥6 mm for children whose left kidney was longer than the right
(specificity of 88% and 84%, respectively).
Conclusion: Renal length discrepancy observed via ultrasound can be a valuable, noninvasive
tool in predicting renal abnormalities detectable by DMSA scan in children, aiding
clinical decision-making and potentially reducing the need for more invasive procedures.
However, ultrasound has moderate sensitivity and reasonable specificity for predicting
positive DMSA scan results and detecting high-grade vesicoureteral reflux (VUR).
- Dimercaptosuccinic acid (DMSA) scan
- Ultrasonography
- Renal length discrepancy (RLD)
- pediatrics
How to Cite
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