Infantile Hypertrophic Pyloric Stenosis
Rita L Teele
Professor of Radiology, Christchurch School of Medicine, University of Otago and Radiologist/Ultrasonologist, Starship Children's Hospital, National Women's Hospital, Auckland, New Zealand

Abstract
Infantile hypertrophic pyloric stenosis remains a condition of uncertain aetiology. It affects neonates and infants - typically, but not exclusively, firstborn males. There is a definite genetic predisposition. Although the aetiology has not been determined, the use of ultrasonography in diagnosis of pyloric stenosis has been developed and refined over the last 2 decades. With adequate care to preparation, good technique and close observation, the ultrasonographic diagnosis of pyloric stenosis is sensitive and specific. Measurements of the pyloric muscle and channel length provide quantitative support for the diagnosis.