TY - JOUR T1 - Distribution of CT-quantified emphysema: Association with lung function decline JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p4608 AU - Firdaus Mohamed Hoesein AU - Pieter Zanen AU - Bram van Ginneken AU - Rob van Klaveren AU - Mathias Prokop AU - Jan-Willem Lammers Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p4608.abstract N2 - Background: Previous studies showed that subjects with similar extents of CT-quantified emphysema, but with different locations within the lung show different degrees of airflow obstruction.Aim: To assess the association between CT-quantified emphysema distribution (upper/lower lobe) and lung function decline in heavy smokers participating in a lung cancer screening trial.Methods: 587 participants underwent CT-scanning of the lungs and pulmonary function testing at baseline and after a median (interquartile range) follow-up of 2.9 (2.8-3.0) years. The lungs were automatically segmented based on anatomically defined lung lobes. Severity of emphysema was automatically quantified per anatomical lung lobe and was expressed as the 15th percentile technique (point below which 15% of the low attenuation areas voxels are distributed). Linear mixed models, correcting for age, height, BMI, packyears and smoking status, were used to assess the association of emphysema distribution and FEV1/FVC-decline.Results: Mean (SD) age was 60.2 (5.4) years, mean baseline FEV1/FVC was 71.6 (9.0)% and overall mean Perc15 was -908.5 (20.9) HU. Participants with upper lobe predominant emphysema had a 1.71% (95% confidence interval 0.79 - 2.64) lower FEV1/FVC after follow-up compared to participants with lower predominant emphysema (p=0.001), independently of the total extent of emphysemaConclusion: Upper lobe predominant emphysema may be a different phenotype than lower lobe predominant emphysema. ER -