Renal ultrasonography in neonates

Ultrasound [US] is a safe and accurate imaging method in the evaluation of urinary tract and its anomalies in neonates. It is helpful in establishing correct diagnosis in the majority of cases and facilitates precise measurement of kidney length. We conducted this work to study the prevalence and types of renal anomalies in Egyptian neonates and to identify their normal renal length. Our study was conducted on 500 Egyptian neonates, at Alexandria University Maternity and Children's Hospitals. Ultrasonographic examination and measurement of both kidneys were done in all neonates. Abnormal renal ultrasonographic findings were found in 15 neonates, with a prevalence of 3%. The abnormalities encountered were severe bilateral hydronephrosis in 8 cases [1.6%], moderate bilateral hydronephrosis in 3 cases [0.6%]. Horseshoe kidney, bilateral hyperechoic renal medulla, polycystic kidney disease [ARPKD], and unilateral renal tumor were detected in equal frequencies of 0.2% each. Further evaluation of the cases with severe hydronephrosis revealed: posterior urethral valve [PUV] in 5 cases, bilateral primary vesicouretral reflux [VUR] in 2 cases, bilateral pelviureteric junction obstruction [PUJO] in one case. Cases with moderate hydronephrosis resolved on follow-up. Sonographic renal appearance in normal neonates was different from that seen in older children. They showed a pattern of increased corticomedullary differentiation with markedly sonolucent medullary pyramids. The mean renal length in normal newborns was 4.7 +/- 0.7cm. There was a positive correlation between renal length and each of body length and weight than with age and head circumference. The high prevalence of renal anomalies in Egyptian neonates justifies early postnatal renal US examination of all neonates; especially those who had abnormal antenatal ultrasonographic findings. Early diagnosis of such anomalies will lead to proper early management and prevention of chronic renal failure

Cerebral blood flow velocities in newborn infants with perinatal ashpyxia

The cerebrovascular hemodynamic alteration in asphyxia and intraventricular hemorrhage in newborn infants were determined by monitoring the pulsatile flow changes in the anterior cerebral arteries using Doppler ultrasound. The pulsatility index measurements, which were calculated from the recorded changes in Doppler frequency shifts, were obtained in four groups of newborn infants, each comprising 20, with the following diagnoses: Group I normal term, Group II asphyxia, Group III IVH, Group IV asymptomatic preterm. There was no significant difference between the PI values of groups I and IV. Compared to normal term infants, those diagnosed as having asphyxia had significantly lower PI measurements and those with IVH had significantly higher PI values. The low PI values in asphyxia and prior to the onset of IVH indicate vasodilatation and decreased resistance to blood flow. In IVH, the high PI values denote the opposite. PI =Pulsatility index; S = Mean systolic amplitude; D = mean diastolic amplitude; CBF= Cerebral blood flow; IVH= Intraventricular hemorrhage; AGA= Appropriate for gestational age