[Ultrasound misdiagnosis of gallbladder concrements in "phrygian cap" deformity (author's transl)].

Gallbladder septa, for example, in "phrygian cap" deformity, may in rare cases lead to a misdiagnosis of gallbladder stones when B-mode ultrasound with gray scale is used. Among 4,000 upper abdominal ultrasound examinations which included the gallbladder one such case was observed. In view of the frequency of septated gallbladders (about 15%) this, although very rare, cause of false-positive diagnosis of stone should be taken into consideration when interpreting ultrasound tracings.