PT - JOURNAL ARTICLE AU - Penny L. Hubbard AU - Geoff J.M. Parker AU - Dave Singh AU - Jørgen Vestbo AU - Eva Bondesson AU - Lars E. Olsson AU - Lars Wigström AU - Simon S. Young AU - Josephine H. Naish TI - Novel ventilation-perfusion ratio measurements in COPD using MRI DP - 2011 Sep 01 TA - European Respiratory Journal PG - 1880 VI - 38 IP - Suppl 55 4099 - http://erj.ersjournals.com/content/38/Suppl_55/1880.short 4100 - http://erj.ersjournals.com/content/38/Suppl_55/1880.full SO - Eur Respir J2011 Sep 01; 38 AB - We present a novel analysis of oxygen-enhanced (OE)MRI data in COPD that allows quantitative ventilation-perfusion ratio (V/Q) maps to be determined. Representative V/Q maps of: A healthy; B moderate & C severe COPD subjects reveal homogeneous maps for A and considerable heterogeneity in B/C.Group-average histograms (labelled as above) show a narrow peak in A; the peak broadens and a lower V/Q peak becomes evident in B/C. A high V/Q tail is also seen in C.OEMRI parameters, enhancing fraction (EF) and interquartile range (IQR) V/Q, show significant differences between A & B/C. Each group had 12 subjects, data averaged over 2 scans. Using a single slice, minimum group sizes to detect a 50% difference of the healthy group window are 27 (EF) & 14 (IQR V/Q). Power calculations are specific to this implementation of the methods, we envisage improvements with further development.View this table:Group mean and SD for OEMRI parametersThe results show strong similarities to published literature using more invasive techniques and enable powering of future intervention studies.