Imaging Case: Answer

Answer: False. Infants present with non-bilious vomiting

Diagnosis: Pyloric Stenosis

Pathology: Pyloric stenosis is hypertrophy and hyperplasia of the pylorus with a multifactorial inheritance in families. The incidence is 5/1000 births in males and 2/1000 births in females. It is therefore more common in males; it is also more common in first-born infants, and in Caucasian infants.

Presentation: An infant will present with non-bilious vomiting that becomes projectile, usually between the ages of 3 weeks to 6 months.

Ultrasound: Considered the standard for diagnosis with an accuracy of 100%, sensitivity approaches 97%
Maximum Normal Measurements of the pylorus: Length 15mm
Single muscle: 3mm
Total Width: 7mm

Findings Consistent with Hypertrophic Pyloric Stenosis:

String Sign: Elongated pylorus with a narrow lumen with only small barium streaks passing through

Antral Nipple Sign: Redundant pyloric mucosa projecting into gastric antrum

Cervix Sign: Indentation of muscle mass on antrum.

Target Sign: Hypertrophied, hypoechoic muscle surrounding echogenic mucosa:


  • Check BMP patients are at risk for hypochloremic, hypokalemic metabolic alkalosis from repeated vomiting episodes 
  • Rehydration therapy and correction of electrolyte imbalances, if indicated 
  • Definitive therapy with pyloromyotomy (surgery)

Disposition: Admission. Patients typically go to surgical floor, however level of care is dependent upon lab values and clinical stability.

1. Radiopedia: Pyloric Stenosis