Comparison of AP supine vs PA upright methods of chest roentgenography in infants and young children.

Various arguments have been advanced for preferring either the AP recumbent projection or the PA upright projection in chest roentgenography of infants and young children. One prominent argument for PA projection is that it shows less magnification.In a search of the literature, no study could be identified that statistically compares the cardiothoracic ratios in a series of patients with simultaneous PA upright and AP supine chest roentgenograms. This study addresses that point and also examines other factors in the two different projections.A survey of pediatric radiology departments in the United States shows an overall preference for the AP supine projection by a factor of 2:1. Statistical analysis of the two methods in this study demonstrates no significant difference in the cardiothoracic ratios. All other factors considered, the authors are of the opinion that the AP supine projection is more desirable in the infant and young child.