Measurement of the length from vocal cord to carina and diameter of the trachea with a three-dimensional chest CT scan in adults; comparison with demographic data

ABSTRACT

BACKGROUND: Most morphometric studies of the airway have relied on plain radiographs or CT scan with their attendant limitations. We evaluated the length from vocal cord to carina and diameter of the trachea in adults who had no abnormality of the airway using three-dimensional chest CT scan and compared with demographic data. METHODS: We performed a multiplane reconstruction of the airway using axial, sagittal, and coronal slices (aged 18-87, 100 men, 100 women). We measured that the lengths from vocal cord to carina and the diameters (AP, anteroposterior; TR, transverse) of 50 mm above carina of the trachea. RESULTS: The lengths from vocal cord to carina was 130.2 +/- 11.4 mm in men and 119.5 +/- 10.5 mm in women. The AP and TR diameters of the trachea at 50 mm above carina were men; 18.0 +/- 2.4 mm, 17.2 +/- 2.6 mm, women; 14.4 +/- 2.0 mm, 14.4 +/- 1.9 mm, respectively. The correlation between airway length and age and height was statically significant in men and women but less clinically significant. The correlation between diameter of trachea and height was only statically significant in men but less clinically significant. CONCLUSIONS: This study suggests that these measured data are helpful for the endotracheal intubation and endotracheal tube placement in airway management.