Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 39 3 2017 08 06 Correlation between color doppler ultrasonographic indices and serum creatinine level before and after renal transplantation 55 60 EN Abolhassan Shakeri Hamid Tayebi Khosroshahi Alireza Mirfakhraei Daniel Fadaei Fouladi Journal Article 2017 07 09 Background: The measurement of color Doppler ultrasonographic indices, such as resistive index (RI) can help in the evaluation of a transplanted kidney. This study sought to examine correlation between color Doppler ultrasonographic indices and serum creatinine levels before and after renal transplantation. Methods: A total of 100 patients with end stage renal disease undergoing kidney transplantation were enrolled in this study. Serum creatinine levels was measured before transplantation, on day 5 and at the end of the third month after transplantation. Central and peripheral RI values of the transplanted kidney were also documented on day 5 an month 3 posttransplantation. Results: Creatinine level at the end of third month had positive correlation with central (r=0.27 and p=0.007) and peripheral RI values (r=0.26 and p=0.009) in day 5 after transplantation. There was also a significant positive correlation between the serum level of creatinine at the end of the third month and central (r=0.50 and p<0.001) and peripheral RI values (r=0.50 and p<0.001) at the third month posttransplantation. At an optimal cut-off point of 0.51 for the central RI on fifth day, the sensitivity, specificity, positive predictive value, and negative predictive value for predicting a malfunctioning transplanted kidney were 93%, 30%, 76%, and 64%, respectively. The corresponding values of the peripheral RI on fifth day were 43%, 67%, 75%, and 33%, respectively using an optimal cut-off point equivalent to 0.70. Conclusions: Both peripheral and central RI values on day 5 can be used for predicting malfunctioning transplanted kidney.