Caterpillar Sign in Infantile Hypertrophic Pyloric Stenosis - An upper gastrointestinal radiographic series was obtained (ultrasonography was not readily available as the initial test), and the findings showed a distended, air-filled stomach with undulating contours, known as the “caterpillar” sign. This sign is visible when active hyperperistaltic waves come to an abrupt stop at the pylorus — a finding that is suggestive of hypertrophy. #Clinical #Peds #Radiology #PyloricStenosis #Caterpillar #Sign #AXR #KUB #NEJM
