Kidney transplant: usefulness of real-time elastography (RTE) in the diagnosis of graft interstitial fibrosis

Abstract

The aim of this study is to evaluate the usefulness of real-time elastography (RTE) in the diagnosis of graft interstitial fibrosis. We prospectively enrolled 50 patients clinically suspected of graft fibrosis. RTE was performed with a broadband linear transducer using a dedicated ultrasound machine. Tissue mean elasticity (TME) was calculated by two blinded operators. All patients underwent biopsy after RTE. To determine cortical fibrosis Banff score was used. The receiver operating characteristic curves analysis was performed to evaluate the accuracy of TME to discriminate between patients with mild fibrosis (F1) versus patients with moderate to severe fibrosis (F2-F3). Inverse correlation between TME values and the degree of fibrosis has been shown (p < 0.05). Patients with F1 had mean TME values significantly higher compared with TME in patients with F2 (p = 0.005) and F3 (p = 0.004). The diagnostic accuracy of TME measurement for F2-F3 evaluated by area under the curve-receiver operating characteristic analysis was 0.95. RTE was able to evaluate kidney fibrosis in a non-invasive way and could be used as complementary imaging during follow-up of renal transplant patients.

Keywords: Allograft biopsy; Elasticity imaging; Graft histology; Kidney transplantation; Ultrasound imaging.