TY - JOUR T1 - MRI equilibrium signal mapping is a quantitative and reproducible alternative to CT for the estimation of lung density in COPD JF - European Respiratory Journal JO - Eur Respir J VL - 40 IS - Suppl 56 SP - 376 AU - Weijuan Zhang AU - Penny Hubbard AU - Eva Bondesson AU - Lars Wigström AU - Simon Young AU - David Singh AU - Josephine Naish AU - Geoffrey Parker Y1 - 2012/09/01 UR - http://erj.ersjournals.com/content/40/Suppl_56/376.abstract N2 - In MRI, the equilibrium tissue magnetisation is proportional to tissue water density. This study aimed to explore the feasibility and reproducibility of mapping the signal (S0) associated with the equilibrium magnetisation in the assessment of structural abnormalities in COPD.MR images were acquired in 12 COPD subjects twice within 1 week for T1 and S0 mapping. Lung S0 was normalized by dividing by muscle S0 to obtain a quantitative S0 (qS0). Matched CT slices were selected to calculate PD15 and RA-950.Lung qS0 maps were reproducible with reduced values seen in regions comparable to CT detected emphysema regions. The mean and 15th, 50th, 75th percentile qS0 showed strong correlations with PD15 and RA-950.Equilibrium signal maps of MRI correlate strongly with CT density estimates, indicating that qS0 may be a reproducible, non-invasive/-ionising measure for quantifying lung density changes in COPD.View this table:Table 1. Pearson correlation coefficient between lung qS0 values and quantitative CT parameters ER -