Pyloric stenosis

Case contributed by Frank Gaillard


Infant presenting with forceful vomiting.

Patient Data

Age: 3 weeks
Gender: Male

Upper abdominal ultrasound


Ultrasound of the pylorus demonstrates 4mm thick pyloric muscle and increased length of the pyloric canal to 20mm. The thickened muscle forms a prominent hypoechoic target sign on transverse (sagittal with respect to the trunk) imaging . Also note the protrusion of pyloric mucosa in to the antrum.

Diagram of measurements


In a normal situation, the pyloric muscle thickness (diame­ter of a single muscular wall on a transverse image) should normally be less than 3 mm (most accurate) and the length (longitudinal measurement) should not exceed 15 mm.

Case Discussion

In the correct clinical scenario the diagnosis of pyloric stenosis stenosis can be made with confidence on the basis of ultrasound alone. 

Case courtesy of Bob Cook, MD. Western Memorial Regional Hospital Corner Brook, Newfoundland.

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