Automatic analysis of bronchus-artery ratios and mucus plugs of 640 chest CTs of EMBARC bronchiectasis patients

<bold>Aims:</bold> To establish the severity and extent of bronchus and artery (BA) changes and to detect mucus plugs (MP) on chest CTs using automatic algorithms in bronchiectasis patients enrolled into the EMBARC registry. <bold>Methods:</bold> LungQ-BA automatically segments the bronchial tree and identifies the segmental (G0) and distal (G1-29) airway generations. For each BA-pair, the following dimensions are quantified: diameters of bronchial outer edge (Bout), inner edge (Bin), wall thickness (Bwt), and artery (A). From these dimensions, BA-ratios are computed: Bout/A, Bin/A, Bwt/A, and bronchial wall area/ outer area (Bwa/Boa). LungQ-MP automatically segments the bronchial tree, detects the total mucus plug number, and quantifies their total volume. Data are expressed as median (IQR). <bold>Results:</bold> 640 CTs were successfully analyzed. 141978 BA-pairs, average 222 BA-pairs/CT, were detected. The Bout/A, Bin/A, Bwt/A, and Bwa/Boa for G1-6 were 1.34 (1.07, 1.72), 1.04 (0.81, 1.35), 0.13 (0.1, 0.2), and 0.37 (0.29, 0.47), respectively. 12943 MPs were detected on 83% of CTs with a median plug count of 8 (2, 25) and a total mucus volume of 0.44 (0.06, 1.63) mL per CT. <bold>Conclusions:</bold> The automatic analysis of chest CTs of the EMBARC study participants shows severe widening and thickening of bronchi. However, there is a wide range of severities and extents. The next step is to relate BA and MP outcomes to other clinical parameters in the EMBARC registry.