Gastric outlet obstruction occurs when the passage of stomach contents into the duodenum is blocked. In infants, the most common cause is hypertrophic pyloric stenosis, where the pyloric muscle becomes abnormally thickened and obstructs the gastric outlet. Ultrasound is the diagnostic test of choice for pyloric stenosis, measuring the thickness and length of the pyloric muscle. A muscle thickness greater than 3 millimeters and a channel length greater than 15 millimeters are diagnostic criteria. In adults, gastric outlet obstruction can be caused by peptic ulcer disease, gastric cancer, or pancreatic tumors, and ultrasound may show a distended, fluid-filled stomach.
Sonography Term