Postnatal investigation of fetal renal disease.

Following the introduction of routine prenatal scanning, and more recently detailed anomaly scans, antenatal ultrasound (US) diagnosis of fetal renal tract abnormalities has become well established. Prenatal detection has resulted in a group of asymptomatic infants becoming patients in the last two decades. These infants are referred for paediatric (general, urological and nephrological) consultations, radiological imaging and monitoring. The urgency with which to undertake imaging depends on the suspected antenatal diagnosis and clinical scenario, with bilateral hydronephrosis, posterior urethral valves and complicated duplex systems taking a high priority. Treatment is mainly preventive and relies on close follow-up and timely intervention. US remains the main imaging modality of choice postnatally; together with nuclear medicine, it gives a powerful combination of both anatomy and function. However, magnetic resonance urography may have increasing importance in becoming the investigation of choice of the future for more complex cases.