This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
Minimum fluid collection required for radiological detection of pleural effusion in lateral decubitus view is: September 2009 
Select and explain. 
A. 15 ml, B. 25 ml, C. 35 ml, D. 45 ml
B: 25 ml
Answer: B: 25 ml 
Explanation: Ans. Amount of pleural fluid required to cause a blunted costophrenic angle discernible on chest radiography is more than 300 ml. A chest computerized tomography scan is more sensitive than a simple chest x-ray and is often used for assessment of loculated effusions because, in some instances, up to 500 cc of loculated fluid can be obscured behind the dome of the diaphragm