Evaluation of acoustic radiation force impulse (ARFI) elastography as non-invasive diagnostic tool in living donor liver transplantation.

Abstract

Role of acoustic radiation force impulse (ARFI) elastography, in transplant setting, is not well established. We aimed to define the normal mean values of the liver stiffness by ARFI Elastography in healthy liver donors and to evaluate ARFI elastography as predictor of graft fibrosis post living donor liver transplant (LDLT) in comparison to other non-invasive methods (transient elastography [TE], APRI and FIB4). A total of 100 subjects (70 recipients and 30 donors) were recruited. APRI and FIB4 scores were calculated for all recipients. TE and ARFI elastography (Siemens Acuson S2000 Ultrasound System, Germany) were performed to all subjects. All donors and only 30 recipients had liver biopsy. Significant fibrosis was defined as ≥ F2. The mean ARFI velocity among the donors was 1.05 ± 0.09m/s. Regarding the recipients: mean age was 49.5 ± 8.49years, 85.7% males, fibrosis stages < F2 were the most frequent stages by liver biopsy (86.7%) and TE (67.1%). ARFI median was significantly correlated with TE median, APRI and FIB-4 (r = 0.888, p = 0.000; r = 0.62, p = 0.000, and r = 0.585, p = 0.000, respectively). ARFI performed well in discriminating patients with ≥ F2 (AUROC = 0.93, 95% CI 0.86-0.99, p < 0.01) with best cutoff median value of 1.34m/s (sensitivity 90%, specificity 82%). ARFI can be used as a reliable method in assessment of significant fibrosis post-LDLT.