[Color Doppler ultrasound in differential diagnosis of unilateral congenital cystic kidney abnormalities].

Doppler-sonography was performed in 16 newborns with prenatally diagnosed unilateral cystic renal malformation. 11 babies with multicystic dysplastic kidneys showed doppler-sonographically reduced systolic flow velocities and elevated resistive index (RI) [RI = 90-100%] or lack of obtainable perfusion signals. 4 of them had to undergo nephrectomy, the other asymptomatic patients could be managed conservatively, spontaneous regression could be observed. 5 other infants suffering from cystic nephroma, severe ureteropelvic junction obstruction, hudge bleeding of the adrenal gland and hydronephrosis due to ectopic ureter, having been prenatally presented as "cystic renal malformations", initially showed normal systolic flow velocities within renal parenchyma and only slightly elevated RI (mean = 83%). By this they could be differentiated from multicystic kidney dysplasia. We therefore propose to use doppler-sonography for differential diagnosis of prenatally assumed cystic kidney malformations.