Right on Target: A Petite Peds Post

Written by Dr. Michelle DiMare

Welcome back! This month’s post is brought to you by my sudden increase in peds shifts and everyone’s favorite chief complaint: vomiting.

While ultrasounding a tiny, crying, puking, squirmy patient can often seem like a daunting task, this post will hopefully help you hit your target… please forgive that terrible joke.

Because of the sheer number of generally healthy appearing children we see with a complaint of vomiting, it is often difficult to weed out the few that may be in the early stages of a critical illness. Bedside ultrasound can aid in early detection in two cases in particular: pyloric stenosis and intussusception. This post will address bedside ultrasound for pyloric stenosis.

Though pyloric stenosis can lead to severe dehydration early on, children often present with brief episodes of extreme symptoms intermixed with the patient appearing happy and hungry.

The Target: Pyloric Stenosis

pyloric stenosis

Who should you scan?
  • Infants in the first 3 months of life
    • most often around 3 weeks
  • Males more than females in a 4:1 ratio
  • Projectile vomiting in an otherwise hungry appearing baby

How should you scan?
  • Place baby in mom or dad’s lap
  • Avoid feeding prior to US as bowel gas can obscure images
  • Allow to breast or bottle feed a small amount during the ultrasound to soothe the baby
  • Position the baby just slightly raised from supine, left side tilted up
    • This will help direct feeds through pylorus and air away from it
  • “Mow the lawn” as pictured below
    • Scan the whole abdomen in an organized pattern looking for grossly abnormal pathology


  • Localize to the epigastric area, looking for the liver and the gallbladder
    • With pyloric stenosis, the pylorus is often displaced just inferior and adjacent to the gallbladder

What are you looking for?


normal pylorus

Hypertrophic Pyloric Stenosis:


  • No gastric contents freely passing through the canal
  • Hypertrophic pylorus with a single muscle wall measuring >3mm on transverse view
  • Pyloric canal measuring >14 mm

Antral Nipple:

antral nipple

  • Redundant pyloric mucosa protruding into the gastric antrum

Though rare, pyloric stenosis is worth considering in all patients under three months of age with persistent projectile vomiting. Finding the one abnormal case will be much easier if you’ve scanned and seen your fair share of normal anatomy.

Thanks for reading my last post as a fellow. As always, happy scanning!

The following two tabs change content below.


  • Editor in Chief of The Original Kings of County 
  • EM/IM PGY4

Latest posts by jshibata (see all)

Leave a Reply

Your email address will not be published.