The Value of the Double-Track Sign as a Differentiating Factor between Pylorospasm and Hypertrophic Pyloric Stenosis in Infants

Abstract

The development of vomiting in the infant after the immediate neonatal period frequently requires radiographic investigation of the underlying cause. The classical case of hypertrophic pyloric stenosis presents little problem, but an infant with a severe and prolonged pylorospasm may be difficult to differentiate from one with hypertrophic pyloric stenosis. In this communication, a group of proved cases of hypertrophic pyloric stenosis is compared with a similar group of cases of pylorospasm to determine identifying features of each. The main roentgenographic signs of hypertrophic pyloric stenosis are the string (Fig. 1), the shoulder (Figs. 1 and 2), the beak (Figs. 1 and 3), and the tit (Figs. 1 and 4). With the string sign an area of constant narrowing appears to be rigid and free of peristaltic activity in the prepyloric region and pylorus. This is due to the restriction of distensibility by the hyper-trophied muscle of the pylorus. The narrowed channel presents a curve upward and slightly to the left...