Evaluation of incidental pelvic fluid in relation to physiological changes in healthy pubescent children using pelvic magnetic resonance imaging
Peritoneal free fluid can indicate an underlying disease process; however detection of minimal peritoneal free fluid in healthy children is not uncommon.
To assess the significance of incidental peritoneal free fluid within healthy children by MRI and its relation to physiological changes during puberty.
Materials and methods
This prospective study was performed on 32 healthy volunteers (20 boys) between the ages of 8 years and 13 years, with consecutive follow-ups every 8–10 months for an average of 3 years. Body mass index (BMI) z-score, pubertal status, C-reactive protein and sex hormone concentrations were assessed prior to MRI studies. We reviewed a total of 120 pelvic MRI studies (61 boys) and measured the quantity of peritoneal free fluid. For statistical analysis we used linear mixed-model accounting for within-patient correlations.
The mean ± standard deviation volume of peritoneal free fluid was 4.7±5.7 mL in girls and 1.9±3.1 mL in boys, with a maximum volume of 25 mL and 17 mL, respectively. The prevalence of peritoneal free fluid was significantly higher in girls (91%) compared to boys (67%; P=0.0035). In 15% of the girls and 3% of the boys the fluid was greater than 10 mL. The mean volume of peritoneal free fluid in the fourth stage of puberty was higher and significantly different from the mean volume in the first stage of puberty (P=0.01).
Among healthy pubescent children, the prevalence of peritoneal free fluid is significantly higher in girls. The volume of peritoneal free fluid can reach volumes greater than 10 mL during normal puberty, especially in the fourth stage, and can be assumed normal in the absence of active disease.
KeywordsChildren Magnetic resonance imaging Normal values Pelvis Peritoneal free fluid Pubertal stage
Compliance with ethical standards
Conflicts of interest
- 8.Zachmann M, Prader A, Kind HP et al (1974) Testicular volume during adolescence: cross-sectional and longitudinal studies. Helv Paediatr Acta 29:61–72Google Scholar
- 10.Landry A, Docherty P, Ouellette S, Cartier LJ (2017) Causes and outcomes of markedly elevated C-reactive protein levels. Can Fam Physician 63:e316–e323Google Scholar
- 13.Prader A (1966) Testicular size: assessment and clinical importance. Triangle 7:240–243Google Scholar
- 17.Bates D, Mächler M, Bolker B, Walker S (2014) Fitting linear mixed-effects models using lme4. J Stat Softw. https://doi.org/10.18637/jss.v067.i01