Using real-time sound touch elastography to monitor changes in transplant kidney elasticity.

ABSTRACT

AIM: To use sound touch elastography (STE) to assess the changes of renal cortex among different complications following renal transplantation. MATERIALS AND METHODS: A total of 31 patients with renal dysfunction after renal transplantation underwent an ultrasound-guided biopsy for pathological examination with conventional and STE ultrasound. The maximum elastic modulus (Emax) was determined, and the biopsy specimen was evaluated for evidence of significant differences among four different complications drug-induced renal damage, acute rejection, chronic allograft nephropathy (CAN), and BK virus (BKV) nephropathy. Receiver operator characteristics were used to compare the diagnostic efficacy of STE ultrasound according to the pathological results. RESULTS: The quantitative index Emax of the STE technique was statistically significant among the four different complications (p<0.05). The distribution of the magnitude of Emax in the renal cortex was BKV nephropathy > CAN > acute rejection > drug induced renal damage. The renal cortex Emax was statistically different for the severity of renal fibrosis and tubular atrophy (p<0.05). CONCLUSION: Each of the four different complications of transplantation influenced the Emax of the renal cortex differently. Emax can be used to assess the severity of renal fibrosis and tubular atrophy.