Ultrasound renal resistive index is not an organ-specific predictor of allograft outcome.

Background: Ultrasound-measured renal resistive index (RRI) has been suggested to predict allograft survival in renal transplant recipients. Based on experimental and clinical data, we objected to the theory that RRI specifically mirrors allograft characteristics. Instead, we hypothesized that RRI rather represents a marker of systemic vascular damage than an organ-specific marker.