Segmental Bronchial Diameter Measurement at Inspiration-Expiration Phase by Low-dose MSCT in Healthy Volunteers

Li He,Zhai Liu,Qingyun Ren

doi:10.11648/j.ijbmr.20190702.12

Abstract

Objective: This study aimed to evaluate the normal range of quantitative CT in measuring the airway diameter at inspiration-expiration phase using 3D imaging in healthy adults. Materials and Methods: 68 healthy volunteers, including 42 males and 26 females, with the mean age of 49.3 (SD14.7) years, had undergone low-dose CT scan at full inspiration and the end of expiration. All CT scans were performed within the range from the lung apices to the diaphragm, at a tube potential of 120kVp and an effective mAs of 60. Afterwards, all CT images were analyzed using the 3D software (FUJIFILM Corporation SYNAPSE), and the airway tree was generated according to the automated region-growing technique, which was perpendicular to the cross section measurement of the segmental bronchus in bilateral lower lobes. Meanwhile, the imaging of segmental bronchus was classified as at inspiration and expiration phase in male group, and at inspiration and expiration phase in female group. Moreover, the Din-L and Din-S of the segmental bronchus were analyzed quantitatively. Difference in the segmental bronchial diameter between the inspiration and expiration phase group with the same sex was evaluated with paired-t test, while that between the male and female groups was analyzed by a 2-tailed unpaired t test. In addition, the impact of age, height, weight and BMI on Din-L and Din-S was assessed through multiple linear regression analysis. Results: 378 segmental branches in the lower lobe of lung from male group and 234 from female group were shown using the low-dose multi-slice spiral CT (MSCT) scan. All segmental bronchi were detected automatically using the 3D software. Our results suggested that, Din-L and Din-S in segmental bronchus of both male and female groups at inspiration phase were larger than those at expiration phase; and those in male group were greater than those in female group at both inspiration and expiration phases (P < 0.01). Meanwhile, the average of Din-L and Din-S was markedly related to age at both inspiration and expiration phases. Conclusions: The normal reference values and the likely ranges are determined for segmental bronchus diameter in the lower lobe of adult lung at inspiration-expiration phase. The average of Din-L and Din-S is evidently correlated with age and sex at both inspiration and expiration phases. The segmental bronchus diameter at inspiration phase in adolescents is larger than that at expiration phase.

Highlights

With the development of medical imaging technology, multi-slice spiral CT (MSCT) has been extensively applied in clinic, which allows to accurately diagnose numerous diseases, especially for lung and bronchial diseases
Some studies showed the changes in lung volume and bronchial diameter in Chronic obstructive pulmonary disease (COPD) were quantitative measured at inspiration and expiration phase [9,10,11], while some studies have used low-dose CT scans [12,13]
All images obtained from 68 subjects undergoing low-dose

Summary

Introduction

With the development of medical imaging technology, multi-slice spiral CT (MSCT) has been extensively applied in clinic, which allows to accurately diagnose numerous diseases, especially for lung and bronchial diseases. Bronchial measurements can be obtained from the MSCT scan of lungs using the post-processing software [3, 4]. Many existing studies have focused on the wall thickness, others have measured the lumens of central bronchi, segmental bronchi, or the small airway at inspiration phase. Some studies showed the changes in lung volume and bronchial diameter in COPD were quantitative measured at inspiration and expiration phase [9,10,11], while some studies have used low-dose CT scans [12,13]. Wall thickness and airway intraluminal area of six segmental bronchi (B1, B2, B3, B8, B9, and B10) in the right lung of in patients with COPD at inspiration phase were measured automatically using three-dimensional computed tomography [14]. The segmental bronchial diameter has not been reported within the normal range of expiratory and inspiratory phase scanning

Methods

Results

Conclusion