This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Initial Assessment, Subject name: Surgery
Use of FAST? 
Select and explain. 
A. To detect fluid in pericardial and peritoneal sacs, B. Pyoperitoneum, C. Intestinal obstruction, D. Pancreatitis
A: To detect fluid in pericardial and peritoneal sacs
Answer: A: To detect fluid in pericardial and peritoneal sacs 
Explanation: Ans. is 'a' i.e., To detect fluid in pericardial and peritoneal sacs o FASTFocused Assessment of Sonographic examination of Trauma patient is a rapid diagnostic examination to assess patients with potential thoraco abdominal injuries.It sequentially survavs for pressence of blood in pericardial sac and dependent abdominal regions.It is exquistely sensitive for detecting fluid of > 250 ml. After application of vs transmission gel, a 3.5 MHZ convex transducer is used to assess, in sequence-pericardial area, RUQ, LUQ and Pelvis.It is very accurate in assessing Hypotensive patients with blunt trauma abdomen; if FAST positive, immediate surgery is justified.