A 28-year-old male presents after a high-speed motor vehicle accident. FAST examination is performed. Which of the following is the MOST sensitive ultrasound window for detecting free intraperitoneal fluid in FAST?
- A Perihepatic (Morrison's pouch)
- B Pericardial window
- C Pelvis (pouch of Douglas) ✓
- D Perisplenic window
Correct answer: C. Pelvis (pouch of Douglas)
Explanation
The pelvic window (pouch of Douglas in females, rectovesical pouch in males) is the most dependent part of the peritoneal cavity in the supine position and therefore the most sensitive location for detecting small amounts of free intraperitoneal fluid on FAST. Morrison's pouch (hepatorenal space) is the most commonly used initial window but is less sensitive for small volumes. As little as 50–100 mL can be detected in the pelvis.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.