AIRWAY MEASUREMENT USING MORPHOMETRIC ANALYSIS

Measurement of airway size using endoscopic morphometry was investigat ed. Endoscopic images of the porcine tracheobronchial tree were obtain ed via a Storz system at a known distance from the telescope. The bron chi were marked with transluminal wires, transected, and imaged. All i mages were analyzed morphometrically with a computer image at multiple sites (N = 20). The endoscopic measurements were plotted against the macro lens images so that a straight line with a slope of 1 would indi cate a consistent correlation. Area measurements for all images had a slope of 0.67 (r = .885); however, for images with area < 80 mm(2) the slope was 1 (r = .928) and for images with area > 80 mm(2) the slope was -0.63 (r = .757). Minor axis measurements had a slope for all imag es of 0.71 (r = .879), for images with area < 80 mm(2) of 0.93 (r = .8 75), and for images with area > 80 mm(2) of -0.34 (r = .482), and majo r axis had a slope for all images of 0.73 (r = .904), for images with area < 80 mm(2) of 0.88 (r = .923), and for images with area > 80 mm(2 ) of -0.59 (r = .771). Accurate area measurements as well as major and minor axis measurements can be obtained for airways with area < 80 mm (2) by means of this system. Each bronchoscope-telescope unit has an o ptimal target size for which measurements are accurate.