Diagnosis of hypertrophic pyloric stenosis: value of sonography when used in conjunction with clinical findings and laboratory data.
OBJECTIVE
This study aimed to determine the value of sonography in the diagnosis of hypertrophic pyloric stenosis in patients with no palpable olive-shaped mass.


METHODS
One hundred and five children with projectile vomiting but no palpable mass had sonography because of possible hypertrophic pyloric stenosis. The patients' history, signs and symptoms, and results of laboratory tests were incorporated into the statistical analysis. Using medical history, signs and symptoms, and laboratory results in one case and history, signs and symptoms, laboratory results, and pyloric measurements based on sonographic findings in another case, we composed the best predicting logistic regression models.


RESULTS
The ability to predict hypertrophic pyloric stenosis is greatly increased by adding information obtained from sonography. At 91% specificity of the final model, only 5% of the patients with no evidence of the abnormality actually had hypertrophic pyloric stenosis. The positive predictive value is thus 94%, and the negative predictive value is 95%.


CONCLUSIONS
The results justify the use of sonography as the diagnostic procedure of choice for infants suspected of having hypertrophic pyloric stenosis.
van der Schouw
Y T
YT
Department of Medical Informatics and Epidemiology, University of Nijmegen, The Netherlands.
van der Velden
M T
MT
Hitge-Boetes
C
C
Verbeek
A L
AL
Ruijs
S H
SH
D005260:Female; D006801:Humans; D006984:Hypertrophy; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D015995:Prevalence; D011707:Pyloric Stenosis / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000453:epidemiology; D011708:Pylorus / Q000000981:diagnostic imaging / Q000473:pathology; D012372:ROC Curve; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D014463:Ultrasonography