Pediatric Radiology > Abdominal > Upper GI > Hypertrophic Pyloric Stenosis - Radiographic Features

Hypertrophic Pyloric Stenosis - Radiographic Features

The plain XR will show a "single bubble" with air in a distended stomach. An elongated and narrowed pyloric canal (2-4cm in length) results in a "string" sign when a small amount of barium streaks through the pyloric canal. A transient triangular tent-like cleft/niche in the middle of the pyloric canal is called the "diamond" sign. There is an outpouching along the lesser curvature because of antral peristalsis disruption. Active gastric hyperperistaltic waves is the "caterpillar sign." A mass impression upon the antrum with a streak of barium pointing toward the pyloric canal is known as "antral beaking." Indentation of the base of the bulb (occuring in 50%) is called the Kirklin sign or "mushroom" sign. There is gastric distension with fluid and/or air.

"Single Bubble" sign of dilated stomach.	Upper GI study with barium demonstrating the "mushroom" sign.