This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Benign Gastric Disease, Subject name: Surgery
Investigation of choice in pyloric stenosis- 
Select and explain. 
A. USG, B. UGI series, C. CT, D. MRI
A: USG
Answer: A: USG 
Explanation: Ans. is 'a' i.e., USG o "The diagnosis of HP S is made by ultrasound scan or UGI series " - Sabistono "When olive cannot be palpated, ultrasonsgaraphy can diagnose the condition accurately in 95% of patients. Criteria for USG diagnosis include a channel length of> 16 mm and pylonic thickness of > 4 mm " - Schwartz