The use of renal Doppler ultrasonography to diagnose patent ductus arteriosus in preterm infants

Objective. To prospectively study the diagnostic usefulness of altered rena l waveforms in patent ductus arteriosus. Methods. We studied preterm Infant s undergoing echocardiography for a suspected patent ductus arteriosus. A s pectral Doppler display was acquired for both renal arteries, and a resisti ve index was obtained. Sensitivity, specificity, and likelihood ratios were calculated using a clinically significant patent ductus arteriosus (>1.5-m m diameter on color Doppler ultrasonography) as the standard of reference. Results. Fifty infants had 78 scans. A significant patent ductus arteriosus was present on 39 scans, When the renal resistive index was greater than 1 .0, the likelihood ratio for a significant patent ductus arteriosus was 24. 8 (specificity, 97.2%; SID, 3.8%). When the renal resistive index was 1.0 o r less, the likelihood ratio for a significant patent ductus arteriosus was 0.2 (sensitivity, 77.2%; SID, 9.4%). Conclusions, Renal resistive index me asurement is a simple investigation that can predict a significant patent d uctus arteriosus In patients without congenital heart disease or other caus es of diastolic runoff when echocardiography is unavailable.