The urinal artifact.
Abrupt narrowing of the male anterior urethra has been increasingly observed during voiding cystourethrography due to extrinsic pressure from a urinal. The true nature of this narrowing must be recognized to avoid misinterpretation.
D006801:Humans; D008297:Male; D011859:Radiography; D014521:Urethra / Q000000981:diagnostic imaging*; D014554:Urination