Hypertrophic pyloric stenosis in the infant without a palpable olive: accuracy of sonographic diagnosis.

PURPOSE: To evaluate the accuracy of sonography for both diagnosis and exclusion of pyloric stenosis in the infant with nonbilious vomiting without a palpable olive and to clarify the relationship between infant age and size and the dimensions of the hypertrophic pylorus.

MATERIALS AND METHODS: The sonograms of 152 infants with suspected pyloric stenosis were evaluated. The prospective diagnoses were categorized as pyloric stenosis, normal pylorus, and pylorospasm with potential to progress to pyloric stenosis. Positive findings were confirmed at surgery; negative findings were confirmed by means of chart review.

RESULTS: Sensitivity, specificity, and accuracy of sonography in determination of appropriate surgical referral were 100%. A significant (P < .05) correlation was found between the size of the hypertrophied muscle and the age of the patient at initial examination.

CONCLUSION: Sonography is highly sensitive and, in this patient population, highly specific, and by virtue of direct visualization of the pyloric muscle, it is the method of choice for both diagnosis and exclusion of pyloric stenosis.