The Lipliner Sign: Potential Cause of a False Positive Focused Assessment with Sonography in Trauma (FAST) Examination.

Background: The focused assessment with sonography in trauma (FAST) examination plays an essential role in diagnosing hemoperitoneum in trauma patients to guide prompt operative management. The FAST examination is highly specific for hemoperitoneum in trauma patients, and has been adopted in nontrauma patients to identify intraperitoneal fluid as a cause of abdominal pain or distension. However, causes of false positive FAST examinations have been described and require prompt recognition to avoid diagnostic uncertainty and inappropriate procedures.