<prompt> Hypertrophic pyloric stenosis is best diagnosed by -USGCT SCANX-ray abdo supineMRI  <response>: Ans. is a i.e., USG Hypertophic pyloric stenosiso Most common cause of nonbilious vomiting is Hypertrophic pyloric stenosis,o Male female.o Vomiting starts with 3 week of age.o Palpable mass is seen in epigastric region,o Visible peristalsis is seen soon after feeding,o Confirmed by USG abdomen,o Contrast study shows :Shoulder signDouble tract sign.o Treatment surgery Ramstedt procedure. 