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Pediatric reference values for total psoas muscle area in Korean children and adolescents
Jisoo Kim1, Mi-Jung Lee1, Hyun Ji Lim1
1Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Insights
Establishing pediatric reference values for total psoas muscle area (tPMA) is crucial due to growth variations. This study provides sex- and age-specific tPMA growth charts for Korean children, aiding muscle mass assessment.
Area of Science:
- Pediatric radiology
- Medical imaging analysis
- Body composition assessment
Background:
- Standardized cut-off values for muscle mass are unsuitable for children owing to significant growth-related changes in muscle mass.
- Variations in race and lifestyle among different populations necessitate the establishment of reference values specific to healthy children.
Purpose of the Study:
- To establish sex-specific and age-specific reference values for total psoas muscle area (tPMA) in pediatric patients.
- To develop growth charts for tPMA to aid in the evaluation of muscle mass in children.
- To analyze the correlation between tPMA and anthropometric measurements like height and weight in children.
Main Methods:
- Retrospective analysis of abdominal CT scans from 740 pediatric patients (≤18 years) presenting with abdominal pain.
- Semi-automated calculation of total psoas muscle area (tPMA) at L3-4 and L4-5 vertebral levels.
- Comparison of tPMA data with Korean national growth charts and correlation analysis with height and weight using quantile regression.
Main Results:
- The study included 740 pediatric patients (340 males, 400 females) aged 12 years (IQR 9-16).
- Sex-specific 50th percentile tPMA values were determined for L3-4 and L4-5 levels, showing significant variation.
- Strong positive correlations were observed between tPMA and both weight and height in both males and females (P < 0.001).
Conclusions:
- Sex- and age-specific growth charts for tPMA in Korean children were successfully generated.
- An online calculator for tPMA at L3-4 and L4-5 was developed, serving as a valuable tool for muscle mass evaluation in pediatric patients.
- These resources facilitate objective assessment of muscle mass, addressing the need for tailored reference values in pediatric populations.
Background:
Uniform cut-off values cannot be applied to children because muscle mass changes significantly with growth and different population groups have different races and lifestyles, so reference values from healthy children are needed.
Materials And Methods:
Pediatric patients (≤18 years of age) who underwent abdominal CT for abdominal pain in the emergency room without a past history from January 2015 to January 2021 were enrolled. Total psoas muscle area (tPMA) was calculated as bilateral psoas muscle areas drawn semi-automatically at the levels of L3-4 and L4-5. Graphs for weight and height were drawn and compared using data from the Korean national growth chart. tPMA distributions according to sex and age were obtained using quantile regression with smoothed polynomials. We analyzed correlations of tPMA with weight and height.
Results:
A total of 740 pediatric patients were included [M:F = 340:400, 12 years (interquartile range 9-16)]. When compared to the Korean national growth chart, the 50th percentile values for height and weight in study population were not significantly different. At L3-4, the 50th percentile tPMA values ranged from 416 to 2,802 mm2 in males and 370 to 1,501 mm2 in females. The 50th percentile tPMA values for L4-5 ranged from 556 to 3,563 mm2 in males and from 579 to 2007 mm2 in females. In males, tPMA at L3-4 and L4-5 showed positive correlations with weight (r = 0.87; r = 0.87, P < 0.001, both) and height (r = 0.82; r = 0.84, P < 0.001, both). tPMA at L3-4 and L4-5 were positively correlated with weight (r = 0.77; r = 0.81, P < 0.001, both) and height (r = 0.61; r = 0.67, P < 0.001, both) in females.
Conclusion:
We provided sex-specific and age-specific growth charts and developed an online calculator for tPMA at the levels of L3-4 and L4-5, which can serve as an evaluation guide for muscle mass in Korean children.

