%0 Journal Article
%@ 2329-4302
%A Quan, K
%A Tanno, R
%A Shipley, RJ
%A Brown, JS
%A Jacob, J
%A Hurst, JR
%A Hawkes, DJ
%D 2019
%F discovery:10082675
%J Journal of Medical Imaging
%K tapering; computed tomography (CT) simulations; reproducibility; airways; CT metrology
%N 3
%T Reproducibility of an airway tapering measurement in computed tomography with application to bronchiectasis
%U https://discovery.ucl.ac.uk/id/eprint/10082675/
%V 6
%X We propose a pipeline to acquire a scalar tapering measurement from the carina to the most distal  point of an individual airway visible on computed tomography (CT). We show the applicability of using tapering  measurements on clinically acquired data by quantifying the reproducibility of the tapering measure. We  generate a spline from the centerline of an airway to measure the area and arclength at contiguous intervals.  The tapering measurement is the gradient of the linear regression between area in log space and arclength. The  reproducibility of the measure was assessed by analyzing different radiation doses, voxel sizes, and reconstruction kernel on single timepoint and longitudinal CT scans and by evaluating the effect of airway bifurcations.  Using 74 airways from 10 CT scans, we show a statistical difference, p ¼ 3.4 × 10−4, in tapering between healthy  airways (n ¼ 35) and those affected by bronchiectasis (n ¼ 39). The difference between the mean of the two  populations is 0.011 mm−1, and the difference between the medians of the two populations was 0.006 mm−1.  The tapering measurement retained a 95% confidence interval of 0.005 mm−1 in a simulated 25 mAs scan and  retained a 95% confidence of 0.005 mm−1 on simulated CTs up to 1.5 times the original voxel size. We have  established an estimate of the precision of the tapering measurement and estimated the effect on precision of  the simulated voxel size and CT scan dose. We recommend that the scanner calibration be undertaken with the  phantoms as described, on the specific CT scanner, radiation dose, and reconstruction algorithm that are to be used in any quantitative studies
%Z Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution  or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.  https://creativecommons.org/licenses/by/4.0/