Normal liver stiffness values measured with MR elastography and two-dimensional shear wave elastography in children aged 9–17 years

PURPOSE: This study aimed to establish pediatric reference ranges for liver stiffness measured by magnetic resonance elastography (MRE) and two‑dimensional shear‑wave ultrasound elastography (2D‑SWE) in healthy Turkish children aged 9-17 years. MATERIALS AND METHODS: Of the 100 initially recruited volunteers, nine were excluded based on strict imaging and biochemical criteria. A final cohort of 91 healthy participants with normal clinical, biochemical, and serological evaluation underwent same‑day MRE (3.0 T, external 60 Hz pneumatic active driver, anterior passive driver paddle over the right upper quadrant, breath‑hold acquisition; non‑vascular ROIs in the right lobe) and 2D‑SWE (intercostal approach, supine position, right arm elevated, 3-5 circular ROIs placed 1.5-2.0 cm below the liver capsule in the right lobe, during end‑expiration breath‑hold). Reference intervals were calculated as mean ±1.96 SD and represent modality‑specific reference limits. Group comparisons were evaluated using the Wilcoxon-Mann-Whitney and Kruskal-Wallis tests. RESULTS: Mean liver stiffness values (LSV) were 2.16 ± 0.24 kPa for MRE (reference interval 1.69-2.63 kPa) and 5.34 ± 1.00 kPa for 2D‑SWE (reference interval 3.38-7.30 kPa). No significant differences were observed across age groups (9-11, 12-14, 15-17 years) or between sexes. Correlations with laboratory values were limited and clinically non‑significant in this healthy cohort. CONCLUSION: Same‑day MRE and 2D‑SWE provide modality‑specific pediatric liver stiffness reference ranges in healthy children aged 9-17 years. These values appear independent of age and sex and should be interpreted as non‑interchangeable, modality‑dependent reference intervals.