Pyloric Stenosis


  • Probe: Linear
  • Mode: Peds Abdomen
  • Depth: 4cm


  • Pylorus in short axis
  • Pylorus in long axis
  • Clip of food passing or unable to pass through pylorus


  • Place the patient in a supine or R lateral decubitus position.
  • Place the probe in the epigastrium with marker facing patient’s right.
  • Use the liver and gallbladder as acoustic window to visualize the pylorus in long axis.
  • Image channel without moving for a period of time to visualize whether food is passing from stomach to small bowel.
  • Turn the probe maker towards the patient’s head to visualize the pylorus in short axis, but pyloric orientation is not the same in every patient.

Normal Measurements

  • Channel length < 14 mm
  • Muscle wall < 3mm

Pyloric Stenosis in Long Axis


Pyloric Stenosis in Short Axis

Unable to identify pylorus

Fix → Increase depth to identify landmarks (liver, gallbladder, stomach). Once stomach is identified, decreased depth, and follow stomach antrum to pylorus.

Measurements are incorrect

Fix → Measure only the hypoechoic muscle layer on the near side of channel to probe.


Fix → Transient muscle spasm can appear like pyloric stenosis by obstructing flow and thickening muscle. Pylorospasm will resolve with feeding, while pyloric stenosis does not.