The Sonographic Double-Track Sign: Not Pathognomonic for Hypertrophic Pyloric Stenosis; Can Be Seen in Pylorospasm

Objective. The "double-track" sign has previously been reported as specific for hypertrophic pyloric stenosis when noted on an upper gastrointestinal series. The sign has been noted on sonographic examinations as well. We sought to determine whether this sign can also be seen in cases of pylorospasm diagnosed by sonography, proving it not to be pathognomonic for hypertrophic pyloric stenosis. Methods. The data obtained prospectively from 91 consecutive patients studied between 1999 and 2002 by sonography for projectile vomiting were retrospectively reviewed. Cases with diagnoses of hypertrophic pyloric stenosis or pylorospasm were reviewed for the imaging finding of the double-track sign. Results. Thirty-seven patients had a sonographic diagnosis of hypertrophic pyloric stenosis that was confirmed surgically. Twenty-six (70.2%) showed a sonographic double-track sign. Thirty-four patients had a sonographic diagnosis of pylorospasm that was confirmed by close clinical follow-up. Eighteen (52.9%) showed a sonographic double-track sign. Conclusions. The sonographic double-track sign can be seen in cases of pylorospasm as well as hypertrophic pyloric stenosis. It is not pathognomonic for hypertrophic pyloric stenosis.