This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Trauma, Subject name: Surgery
Blunt injury abdomen, patient was hemodynamically stable, next investigation 
Select and explain. 
A. X-ray abdomen, B. Barium smallow, C. FAST, D. DPL
C: FAST
Answer: C: FAST 
Explanation: .evaluation of blunt trauma of abdomen ultrasound-useful,simple,non invasive method of evaluating the abdomen. advantages of ultrasound-no danger of radiation,can be done bedside,can be repeated many times,it is cost effective. focused abdominal sonar trauma(FAST)-it is rapid ,non invasive,poable bedside method of investigation focusing on pericardium, splenic , hepatic and pelvic areas.blood more than 100ml in cavities can be identified. (Ref: SRB&;s Manual of Surgery ,5th edition ,pg no. 146)