Tapering analysis of airways with bronchiectasis

Abstract

Bronchiectasis is the permanent dilation of airways. Patients with the disease can suffer recurrent exacerbations, reducing their quality of life. The gold standard to diagnose and monitor bronchiectasis is accomplished by inspection of chest computed tomography (CT) scans. A clinician examines the broncho-arterial ratio to determine if an airway is brochiectatic. The visual analysis assumes the blood vessel diameter remains constant, although this assumption is disputed in the literature. We propose a simple measurement of tapering along the airways to diagnose and monitor bronchiectasis. To this end, we constructed a pipeline to measure the cross-sectional area along the airways at contiguous intervals, starting from the carina to the most distal point observable. Using a phantom with calibrated 3D printed structures, the precision and accuracy of our algorithm extends to the sub voxel level. The tapering measurement is robust to bifurcations along the airway and was applied to chest CT images acquired in clinical practice. The result is a statistical difference in tapering rate between airways with bronchiectasis and controls.

Reproducibility of an airway tapering measurement in computed tomography with application to bronchiectasis

“…The blue-shaded and red-shaded regions correspond to the tubular and bifurcating airways, respectively. A reconstructed healthy airway has been discussed by Quan et al 27 Similar reconstructed cross-sectional images of vessels have been discussed by Oguma et al, 13 Kumar et al, 51 Alverez et al, 52 and Kirby et al 53 …”

“…Importantly, we showed as a proof of principle that the magnitude change in tapering for healthy airways is smaller than those from airways that became bronchiectatic. From our previous work, 60 we showed the measurements are accurate to a sub voxel level. Our findings suggest that our airway tapering measure can be used to assist in the diagnosis of bronchiectasis, to assess the progression of bronchiectasis with time and, potentially, to assess responses to therapy.…”

“…We first, describe in detail the steps to acquire the airway tapering measurement. The method was initially proposed by Quan et al 60 and summarised in Figure 1. The pipeline required two inputs.…”

“…Part of the work have been presented at the 2018 SPIE Medical Imaging conference. 60 For potential conflicts of interest:…”

Modelling Airway Geometry as Stock Market Data Using Bayesian Changepoint Detection

“…In this work, for each airway track, we acquire a series of cross-sectional area measurements using the method proposed by Quan et al [12] (Fig. 1).…”