Diamond sign is seen in-

Ans. is 'a' i.e., Congenital pyloric stenosiso Double/triple track sign is seen in congenital hypertrophic pyloric stenosis.Barium study in CHPSElongation and narrowing of pyloric canal (2-4 cm length)Passing of small barium streak through pyloric canal seen as a string of barium known as string sign.Crowding of muscle folds in pyloric canal known as double/triple track sign.Transient triangular tent-like cleftniche in mid portion of pyloric canal with apex pointing interiorly; seen due to mucosal belonging between 2 separated hypertrophied muscle bundles on greater curvature side within pyloric canal, known as diamond sign/ twining recess.Outpouching along lesser curvature due to disruption of antral peristalsis, known as pyloric teat/teat sign.Mass impression upon antrum with streak of barium pointing toward pyloric channel, known as beak sign/ antral beaking.Indentation of the base of duodenal bulb known as umbrella/kirkin/mushroom sign.Gastric hyperperistaltic waves known as caterpillar sign, a Single bubble sign.Shoulder sign : - Round indentation caused by very hypertrophied pyloric muscle.