Hypertrophic pyloric stenosis: radiologic or sonographic diagnosis?

In this study we analysed ultrasound (US) findings of 73 patients suspected of having hypertrophic pyloric stenosis (HPS). In 43 out of 44 patients with positive US findings, HPS was surgically confirmed. In most of these patients with HPS, 32 (74.4%), pyloric muscle thickness was 4.4-6.2 mm, in 8 patients (18.6%) it was 3.6-4.3 mm and in 3 patients (7,0%) it was 3.0 do 3.5 mm. In only 4 patients we performed barium study due to doubtful values of pyloric muscle thickness on US (3.0-3.5 mm); barium study confirmed HPS in three patients and excluded it in one patient. The pyloric muscle thickness in all patients with HPS was 1.5 times thicker compared to the antral muscle thickness. Ultrasound sensitivity was 93%, specificity 97%, and accuracy 94%. Based on the result of our study, ultrasound examination of the pylorus has proved to be highly recommendable as a routine first method of choice in the diagnosis of HPS.