Radiological kidney size in childhood

Area of Science:

• Pediatric Nephrology
• Radiology
• Biometry

Background:

• Accurate assessment of kidney size and structure is crucial for diagnosing pediatric renal conditions.
• Establishing normative data for kidney dimensions in children is essential for growth monitoring and disease detection.

Purpose of the Study:

• To establish reference values for kidney length (KL), renal area, and renal parenchymal area in children aged 0-14 years.
• To correlate these parameters with age, body height, body surface area, and vertebral distances.
• To define criteria for small kidneys and localized loss of renal parenchyma.

Main Methods:

• Intravenous urograms were analyzed in 255 children without apparent kidney disease.
• Kidney length (KL), renal area, and renal parenchymal area were measured.
• Renal parenchymal thickness at upper and lower poles was determined.
• Statistical comparisons were made with anthropometric data and vertebral measurements.

Main Results:

• Mean left KL was significantly greater than right KL, necessitating separate growth charts.
• A 10 cm increase in body height correlated with a 6.3 mm increase in left KL and 6.0 mm in right KL.
• Criteria for small kidneys were defined based on KL below -2 SD and/or KL ratio outside +/- 2 SD.
• Localized parenchymal loss was indicated by altered upper/lower pole thickness ratios.

Conclusions:

• Normative data for pediatric kidney dimensions were established.
• Separate growth charts for left and right kidney length are recommended.
• Methods for identifying small kidneys and localized parenchymal loss using KL and parenchymal thickness ratios were presented.