Voiding cystourethrography (= VCUG) in a 9-year-old boy with normal shape and limit of the bladder and regular calibre and shape of the whole urethra. Fold of the mucous membrane of the posterior urethra. It is an example of a normal VCUG; the observed structure (crista urethralis) is a fold of the mucous membrane and not obstructive like an abortive type of posterior urethral valves. The VCUG is the appropriate examination to diagnose a vesicoureteral reflux, its grade, and possible additional pathologies. $$harn_01??££See alternate figure 1§§ and $$harn_3??££alternate figure 2.§§