Posterior urethral valves: are neonatal imaging findings predictive of renal function during early childhood?

BACKGROUND: Obstructive renal dysplasia as observed on US is associated with posterior urethral valves and is regarded as predicting poor renal functional outcome. OBJECTIVE: To investigate whether any characteristic of urinary tract imaging at birth is predictive of renal function in children with prenatally diagnosed posterior urethral valves. MATERIALS AND METHODS: We reviewed clinical data including renal function (at birth and up to 3 years of age) and clinical outcome (urinary infection, dialysis, renal transplantation). Imaging data included US (dilatation of the urinary tract, renal cortical echogenicity, signs of cystic dysplasia, urinoma) and cystourethrography findings (vesicoureteral reflux, bladder anomalies, presence of valves) from imaging performed directly after birth. RESULTS: We retrospectively studied 30 children. Three of the 30 (10%) were in renal failure by the age of 3 years. Twelve of 14 (85%) children with parenchymal anomalies (cortical hyperechogenicity or cystic changes) and 8/9 (89%) children with bilateral high-grade reflux had normal renal function at age 3 years. One child without cystic dysplasia or reflux had abnormal renal function from birth. None of the six children with urinoma developed renal failure by the age of 3 years. CONCLUSION: Presence of cortical hyperechogenicity, cystic changes or bilateral reflux cannot be considered prognostic of renal failure by the age of 3 years.

Fetal liver iron overload: the role of MR imaging.

OBJECTIVE: To assess the potential role of MR imaging in the diagnosis of fetal liver iron overload. METHODS: We reviewed seven cases of abnormal liver signal in fetuses referred to MR imaging in a context of suspected congenital infection (n = 2), digestive tract anomalies (n = 3) and hydrops fetalis (n = 2). The average GA of the fetuses was 31 weeks. The antenatal diagnoses were compared with histological data (n = 6) and postnatal work-up (n = 1). RESULTS: Magnetic resonance imaging demonstrated unexpected abnormal fetal liver signal suggestive of iron overload in all cases. The iron overload was confirmed on postnatal biopsy (n = 2) and fetopathology (n = 4). The final diagnosis was hepatic hemosiderosis (haemolytic anaemia (n = 2) and syndromal anomalies (n = 2)) and congenital haemochromatosis (n = 3). In all cases, the liver appeared normal on US. CONCLUSIONS: Magnetic resonance is the only imaging technique able to demonstrate liver iron overload in utero. Yet, the study outlines the fundamental role of MR imaging in cases of congenital haemochromatosis. The antenatal diagnosis of such a condition may prompt ante-(in the case of recurrence) or neonatal treatment, which might improve the prognosis.