Infant with projectile vomiting

US of hypertrophic pyloric stenosis
Sagittal US of the pylorus (middle) shows the calipers on the hypoechoic pyloric muscle which is thickened and elongated, measuring 3.7 mm thick and 20 mm in length. Transverse US of the pylorus (right) shows the circumferentially thickened and hypoechoic pyloric muscle whose boundaries are marked by the calipers surrounding the echogenic mucosa in the center of it.

The diagnosis was hypertrophic pyloric stenosis.