[The "crescent sign" in older children (author's transl)]

The "crescent sign", a dense, convex line parallel to the surface of the kidney, has only been reported in small children with obstructive uropathy during urograms. Two patients (aged 13 and 14 years) with this sign are described. The cause of this appearance is discussed and related to the striations seen on late films in adults with urinary obstruction. The practical value of the "crescent sign" is the possibility of diagnosing obstructive uropathies in the absence of contrast filling of the upper urinary tracts. According to the literature available to us, this is the first time the sign has been reported in older children.