PT  - JOURNAL ARTICLE
AU  - Sanghun Choi
AU  - Babak Haghighi
AU  - Jiwoong Choi
AU  - Eric A Hoffman
AU  - Alejandro P Comellas
AU  - John D Newell
AU  - Sally E Wenzel
AU  - Mario Castro
AU  - Sean B Fain
AU  - Nizar N Jarjour
AU  - Mark L Schiebler
AU  - R Graham Barr
AU  - MeiLan K Han
AU  - Eugene R Bleecker
AU  - Christopher B Cooper
AU  - David Couper
AU  - Nadia Hansel
AU  - Richard E Kanner
AU  - Ella A Kazerooni
AU  - Eric A C Kleerup
AU  - Fernando J Martinez
AU  - Wanda K O’Neal
AU  - Prescott G Woodruff
AU  - Ching-Long Lin
ED  - ,
TI  - Differentiation of quantitative CT imaging phenotypes in asthma versus COPD
AID  - 10.1136/bmjresp-2017-000252
DP  - 2017 Nov 01
TA  - BMJ Open Respiratory Research
PG  - e000252
VI  - 4
IP  - 1
4099  - http://bmjopenrespres.bmj.com/content/4/1/e000252.short
4100  - http://bmjopenrespres.bmj.com/content/4/1/e000252.full
SO  - BMJ Open Resp Res2017 Nov 01; 4
AB  - Introduction Quantitative CT (QCT) imaging-based metrics have quantified disease alterations in asthma and chronic obstructive pulmonary disease (COPD), respectively. We seek to characterise the similarity and disparity between these groups using QCT-derived airway and parenchymal metrics.Methods Asthma and COPD subjects (former-smoker status) were selected with a criterion of post-bronchodilator FEV1 <80%. Healthy non-smokers were included as a control group. Inspiratory and expiratory QCT images of 75 asthmatic, 215 COPD and 94 healthy subjects were evaluated. We compared three segmental variables: airway circularity, normalised wall thickness and normalised hydraulic diameter, indicating heterogeneous airway shape, wall thickening and luminal narrowing, respectively. Using an image registration, we also computed six lobar variables including per cent functional small-airway disease, per cent emphysema, tissue fraction at inspiration, fractional-air-volume change, Jacobian and functional metric characterising anisotropic deformation.Results Compared with healthy subjects, both asthma and COPD subjects demonstrated a decreased airway circularity especially in large and upper lobar airways, and a decreased normalised hydraulic diameter in segmental airways. Besides, COPD subjects had more severe emphysema and small-airway disease, as well as smaller regional tissue fraction and lung deformation, compared with asthmatic subjects. The difference of emphysema, small-airway disease and tissue fraction between asthma and COPD was more prominent in upper and middle lobes.Conclusions Patients with asthma and COPD, with a persistent FEV1 <80%, demonstrated similar alterations in airway geometry compared with controls, but different degrees of alterations in parenchymal regions. Density-based metrics measured at upper and middle lobes were found to be discriminant variables between patients with asthma and COPD.