Coiled spring appearance -

Ans. is 'a' i.e., Intusseption Radiological investigations and signs seen in IntussusceptionPlain filmo Features of small intestinal obstruction o Abdominal soft tissue density in some cases which may showTarget sign - soft-tissue mass with concentric area of lucency due to mesenteric fatMeniscus sign - crescent of gas within colonic lumen that outlines the apex of intussusceptionBarium EnemaClaw sign - rounded apex of intussusception protrudes into the contrast column Coiled spring sign - edematous mucosal folds of returning limb of intussusceptum outlined by contrast material.Ultrasoundo Target signo Bull's eye signo Pseudokidney signAlso knowo Dance sign - feeling of emptiness in rt. iliac fossa on palpation