Journal of Ultrasound in Medicine, Vol 20, Issue 9 1005-1010, Copyright © 2001 by American Institute of Ultrasound in Medicine
The use of renal Doppler ultrasonography to diagnose patent ductus arteriosus in preterm infants
D. L. Armstrong, R. L. Teele, C. A. Kuschel and J. E. Harding
Newborn Services, National Women's Hospital, Auckland, New Zealand.
OBJECTIVE: To prospectively study the diagnostic usefulness of altered
renal waveforms in patent ductus arteriosus. METHODS: We studied preterm
infants undergoing echocardiography for a suspected patent ductus
arteriosus. A spectral Doppler display was acquired for both renal
arteries, and a resistive index was obtained. Sensitivity, specificity, and
likelihood ratios were calculated using a clinically significant patent
ductus arteriosus (>1.5-mm 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%; SD,
3.8%). When the renal resistive index was 1.0 or less, the likelihood ratio
for a significant patent ductus arteriosus was 0.2 (sensitivity, 77.2%; SD,
9.4%). CONCLUSIONS: Renal resistive index measurement is a simple
investigation that can predict a significant patent ductus arteriosus in
patients without congenital heart disease or other causes of diastolic
runoff when echocardiography is unavailable.
