Abstract:

Objective   To examine chronic rejection (CR) features of transplanted kidneys under ultrasonic contrast and find valuable parameters for CR diagnosis by analyzing time intensity curve (TIC). Methods   26 patients who took kidney transplantation more than 3 months before were selected and divided into norejection and CR groups according to a plasma creatinine standard of 110μmol/L(males) and 90 μmol/L(females). The patients with a higher creatinine were pathologically proved to have CR. LOGIQ E9 from GE Company was taken and Sonovue contrast was administered intravenously with a dose of 0.12mg/kg to examine kidney perfusion. Interested parts of ultrasonic performancein the two groups were selected to draft TIC and the following parameters were analyzed: cortex peak strength (A1),  cortex peak time(TtoP1), medulla peak time (TtoP2), difference between TtoP1 and TtoP2 (△TtoP), cortex area under TIC (Area1), medulla area under TIC (Area2) and difference between Area1 and Area2 (△Area). Results   CR transplanted kidneys had a lower filling strength and slower filling speed than others. Except in Area2(P=0.678), significant differences were found in the other parameters between the two groups(P＜0.05), especially in A1, △TtoP, Area1 and △Area(P＜0.01). Conclusion   Ultrasonic contrast on CR transplanted kidneys has characteristic features. Parameters A1, △TtoP, Area1 and △Area are valuable for CR diagnosis.

Key words: Transplanted kidneys; Chronic rejection; Contrast-enhanced ultrasound; Time intensity curve; Peak strength; Peak time