RT Journal Article
SR Electronic
T1 Can quantitative computed tomography (QCT) differentiate between asthma & COPD in patients with similar degrees of airflow limitation?
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P4971
VO 44
IS Suppl 58
A1 Ruth Hartley
A1 Bethan Barker
A1 Mini Pakkal
A1 Chris Newby
A1 Salman Siddiqui
A1 Chris Brightling
A1 Sumit Gupta
YR 2014
UL http://erj.ersjournals.com/content/44/Suppl_58/P4971.abstract
AB Background: Airflow limitation is seen in COPD & asthma.Aim: Using QCT we sought to determine differences between asthma and COPD subjects grouped by airflow limitation.Material & Methods: COPD (n=81), asthma (n=171) & healthy (n=49) subjects had clinical & physiological characterization. COPD & Asthma subjects were split based on FEV1% predicted; Group 0>80%, Group 1 50-80% and Group 2<50%. QCT included average lumen area of segmental bronchi corrected for body surface area (LA/BSA), mean lung density expiratory/inspiratory ratio (MLDE/I), 15th percentile point (Perc15) & fractal dimension of low attenuation clusters in inspiration (LAC-D-950).Results: Asthmatics with moderate airflow limitation have smaller median (IQR) LA/BSA (mm2/m2) when compared to asthmatics with no airflow limitation & COPD with moderate airflow limitation; 9.28[8.28-10.83] v11.15[9.56-13.04]; 11.32[9.63-13.33],p<0.05 respectively. Perc15 is not significantly different between asthmatics with severe airflow limitation & COPD with moderate airflow limitation;-955[-966 to -949] v-958[-971 to -947]HU respectively, but is significantly different (p<0.05) between asthmatics with no airflow limitation & healthy controls. However LAC-D-950 is significantly different between asthmatics with severe airflow limitation & COPD groups 1 & 2; 1.91[1.87-1.96] v1.85[1.78-1.92]; 1.81[1.72-1.89],p<0.05 respectively.Conclusion: Asthmatics with moderate airflow limitation show LA/BSA narrowing compared to spirometrically similar COPD. QCT measured Emphysema may be overestimated in asthmatics with severe airflow limitation as LAC-D-950 remains different between them and COPD.Funded by AirPROM.