Normal Liver Stiffness Values in Children: A Comparison of Three Different Elastography Methods

Area of Science:

• Pediatric Gastroenterology
• Medical Imaging
• Hepatology

Background:

• Noninvasive tests for liver fibrosis are vital in pediatric care to avoid risks associated with invasive procedures like general anesthesia.
• Establishing reliable reference values for noninvasive elastography methods in children is essential for accurate diagnosis and monitoring.

Purpose of the Study:

• To compare two elastography methods, 2D-SWE and pSWE, in children and adolescents aged 4-17 years.
• To establish reference values for these methods, using transient elastography (TE) as a reference in a subset of participants.
• To evaluate the feasibility, agreement, and influencing factors (age, sex) on liver stiffness measurements (LSMs) in this pediatric population.

Main Methods:

• A total of 243 healthy children and adolescents (4-17 years) underwent liver B-mode scans and elastography.
• Liver stiffness measurements were performed using 2D-SWE and pSWE, with TE used as a reference in 87 participants.
• Interobserver agreement was assessed in 50 children.

Main Results:

• Valid measurements were obtained in over 95% of participants for all methods.
• Median LSMs were 3.3 kPa for 2D-SWE, 4.1 kPa for pSWE, and 4.1 kPa for TE.
• 2D-SWE yielded significantly lower LSMs compared to pSWE and TE, with excellent interobserver agreement (0.84 and 0.83).
• LSMs increased with age, and higher values were noted in adolescent males.

Conclusions:

• Both 2D-SWE and pSWE are feasible noninvasive methods for assessing liver stiffness in children.
• 2D-SWE demonstrated a lower failure rate and lower LSM values compared to pSWE and TE.
• Age and sex significantly influence LSM values in pediatric populations, requiring consideration when interpreting results.