The "invisible" can top.
The hazard of ingestion of a beverage can top in a child is presented. These can tops are susprisingly low radio density and their presence can be overlooked on a conventional P.A. X ray of the chest. In such cases a lateral radiograph of the chest should be included in the routine investigation of the child.
D004947:Esophagus / Q000000981:diagnostic imaging*; D005547:Foreign Bodies / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D008297:Male; D011859:Radiography