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
Which is the investigation of choice for fat embolism? 
Select and explain. 
A. CT scan, B. MRI, C. Aerial blood gas analysis, D. Chest x-ray
A: CT scan
Answer: A: CT scan 
Explanation: Ans. is 'a' i.e., CT scanIn case of ARDS due to fat embolism the investigation of choice is spiral CT pulmonary angiogram,