This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gall Bladder & Bile Ducts, Subject name: Surgery
A patient presents with severe pain in right upper quadrant associated with nausea and vomiting, exacerbation during inspiration and tenderness on palpation. Which of the following is the imaging modality of choice for the above patient? 
Select and explain. 
A. Ultrasonography, B. CT Scan, C. MRI, D. X ray
A: Ultrasonography
Answer: A: Ultrasonography 
Explanation: Ans. is 'a' i.e., Ultrasonography * Patient with severe pain in right upper quadrant associated with nausea and vomiting, exacerbation during inspiration and tenderness on palpation is suggestive of probable case of acute cholecystitis with positive murphys sign. Ultrasonography is the modality of choice for the diagnosis of this condition.