ارزش تشخیصی سونوگرافی داپلر در افتراق ازوتمی پیش کلیویاز نکروز حاد توبولار

Background and purpose : Differentiating acute tubular necrosis (ATN) from prerenal azotemia is crucial for selecting the appropriate treatment. Since urinary diagnostic modalities are usually unreliable because of premedications, a rapid and accurate diagnostic modality is needed. This study was conducted to evaluate the diagnostic value of Doppler ultrasonography in differentiating ATN form prerenal azotemia in children. Materials and methods :A total of 50 oliguric or anuric children with previous normal renal laboratory data entered in this study. Doppler examination and calculation of resistance index (RI) were performed within 24 hours of admission and in the recovery phase of ARF. Based on history, clinical follow-up and laboratory studies, diagnosis of underling cause of ARF was made and appropriate treatment started. The sensitivity and specificity of RI in differentiating ATN from prerenal azotemia were assessed. Results :At the cut off points of RI=0.75, the sensitivity and specificity of RI in differentiating prerenal failure and ATN were 91.3% and 85.2%, respectively. Conclusion: Doppler ultrasonography is helpful in differentiating ATN from prerenal azotemia in children. The cut-off value of 0.75 has the highest accuracy in diagnosis.