Fig. 2From: Antenatal and postnatal management of posterior urethral valves: where do we stand?Prenatal ultrasound a, b and fetal MRI c, d , e showing bilateral hydronephrosis (black arrows), distended bladder (B) with dilation of the posterior urethra “the keyhole sign” (white arrows), suggestive of the diagnosis of posterior urethral valveBack to article page