This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Stomach & Duodenum, Subject name: Surgery
Investigation of choice for CHPS 
Select and explain. 
A. USG, B. x-ray, C. CT, D. MRI
A: USG
Answer: A: USG 
Explanation: Ans. (a) USGRef: Bailey and Love page 113-114/26th edition* IOC for Congenital Hypertrophic Pyloric stenosis - USG* Palpated as a Olive tumor in right Upper quadrant.* If the history and clinical mass is there - no need of USG - directly we can do Ramstedt's pylromyotomy