Assessment of Liver Fibrosis Through Shear Wave Elastography in Pediatric Liver Transplant Recipients

Background: Liver transplantation (LT) is the standard therapy for end-stage liver disease. Liver allografts are at risk for fibrosis, for which biopsy is the gold standard for evaluation but carries risks. There is a need for noninvasive modalities to track the trajectory of fibrosis. Methods: We evaluated the diagnostic accuracy of shear wave elastography (SWE) liver stiffness (LS) measurements to quantify fibrosis in pediatric liver transplant recipients. Results: Between 2007 and 2024, 93 patients had 106 liver biopsies performed within 13 months of elastography. LS values were significantly higher in patients with moderate (F2-3) fibrosis compared to those with no significant fibrosis (F0-1) (7.5 ± 0.48 kPa vs. 6.09 ± 0.18 kPa, p = 0.0015). LS values were significantly higher in patients with moderate fibrosis compared to those with no significant fibrosis in both whole (8.4 ± 0.95 kPa vs. 6.6 ± 0.54 kPa, p = 0.02) and segmental allografts (7.1 ± 0.52 kPa vs. 5.9 ± 0.17 kPa, p = 0.02). There was no significant difference in LS values according to allograft type or donor status. The AUROC for LS measurements was 0.71, indicating a good discriminative ability between no significant and moderate fibrosis. A cut-point of 6.09 kPa for SWE was identified, distinguishing between no significant and moderate fibrosis (sensitivity of 81%). A SWE cut-point of 10.40 kPa had a high specificity of 99% in determining moderate fibrosis. Conclusion: We demonstrated a significant association between biopsy fibrosis and SWE LS values and conclude that SWE provides a noninvasive option for monitoring liver a fibrosis.