LAUSR

Background: Most data about the trachea are collected during deep inspiration breath holding (DIBH) using multi-detector computed tomography (MDCT). Images of the physiological changes in the central airway are lacking. Objective: The aim of this study was to explore the physiological changes in the central airway on MDCT during DIBH and deep expiration breath holding (DEBH). Method: The data from 62 patients (38 men and 24 women) who underwent enhanced computed tomography in our hospital were collected. Patients were grouped according to sex and age (18–45, 46–60, and >61 years). Anteroposterior diameter (APD) and transverse diameter (TD) at 3 levels (cricoid, intrathoracic inlet, and 2 cm above the carina), tracheal length, bronchial length, and subcarina angle (SCA) were measured. Results: The average length of the trachea from the cricoid cartilage to the carina was 103.91 ± 10.37 mm at DEBH and 108.63 ± 11.31 mm at DIBH (p < 0.001). The APD of the trachea at the level of the cricoid, intrathoracic inlet, and 2 cm above the carina showed no differences between DEBH and DIBH. The TD of the trachea at the level of the cricoid, intrathoracic inlet, and 2 cm above the carina showed no differences between DEBH and DIBH. The average length of the right main bronchus during DEBH and DIBH was measured as 13.21 ± 3.60 and 13.24 ± 3.49 mm, respectively (p = 0.956). The average length of the left main bronchus at DEBH and DIBH was measured as 44.19 ± 5.50 and 44.27 ± 5.11 mm, respectively (p = 0.929). The average SCA was 81.74 ± 14.56 at DIBH, while it was 80.53 ± 14.38 at DEBH. The change in SCA between DIBH and DEBH showed no significant difference (p = 0.642). Conclusions: The APD at the level of the intrathoracic inlet is larger than that at the cricoid and 2 cm above the carina, while the TD is the opposite. These findings about the trachea and bronchus in our study may contribute to bronchoscopy examinations, tube applications, stent design, and stenting.