TRACHEAL DIAMETERS AND DYNAMICS IN INFANTS AND CHILDREN MEASURED BY CINE-CT

Abstract

Nine children were evaluated for tracheal obstruction by having their intra- and extra-thoracic tracheal diameters measured using Cine-CT. The patients ranged in age from one month to four years, and had clinical signs and symptoms of respiratory distress with stridor. They entered a protocol in which there was full clinical evaluation, and in some, measurement of esophageal pressures and tidal breathing flowvolume loops. The patients were scanned without sedation using a Cine-CT scanner (Imatron, Inc., CA) which provided eight level image acquisition in 240 msec without moving the patients. Using the scanner in the “Cine” mode, 13 to 20 slices obtained over 1 to 2 respiratory cycles were obtained at several levels of both the intra-and extra-thoracic trachea to detail dynamic changes in airway caliber. Images were obtained at relatively low dose and were reconstructed in 14 seconds. Cross-sectional areas of the trachea were obtained by planimetry, and saggital and coronal tracheal diameters directly measured. The clinical and laboratory data correlated well with the imaging measurements, and were compared with Age-related normal Cine-Ct tracheal diameters, and published post-mortem airway caliber data. We conclude that Cine-CT is a rapid method for tomographic evaluation of tracheal dynamics that can be employed for children without sedation.