The value of ultrasound in the diagnosis of congenital hypertrophic pyloric stenosis.

The charts of 103 children with a clinically and surgically confirmed diagnosis of congenital hypertrophic pyloric stenosis were retrospectively reviewed. We found a significant correlation between sonographic and surgical measurements of the muscular thickness of the pylorus (r = .987, P < .001). In 73.7% (76 cases), the clinical picture of gastric outlet obstruction was present when the thickness of the enlarged pyloric muscle was 3.0 mm or more. In 26.3% (27 cases), the pyloric muscle was less than 3.0 mm wide. For 10 patients in whom the muscle width was less than 2.5 mm by sonography, a barium meal was necessary to confirm the diagnosis. The width of the pyloric muscle is the most important factor in the sonographic diagnosis of pyloric stenosis, and even a width of less than 3.0 mm may be associated with clinically significant obstruction.