PT  - JOURNAL ARTICLE
AU  - Bilal Tahir
AU  - Cedric Van Holsbeke
AU  - Ireland Rob
AU  - Swift Andy
AU  - Felix Horn
AU  - Helen Marshall
AU  - Juan Parra-Robles
AU  - Ruth Hartley
AU  - Richard Kay
AU  - Brightling Chris
AU  - Jan De Backer
AU  - Wim Vos
AU  - Jim Wild
TI  - Comparison of CT-based lobar ventilation models with &lt;sup&gt;3&lt;/sup&gt;He MRI ventilation measurements in asthmatics
DP  - 2014 Sep 01
TA  - European Respiratory Journal
PG  - P544
VI  - 44
IP  - Suppl 58
4099  - http://erj.ersjournals.com/content/44/Suppl_58/P544.short
4100  - http://erj.ersjournals.com/content/44/Suppl_58/P544.full
SO  - Eur Respir J2014 Sep 01; 44
AB  - Introduction CT models of ventilation can be computed from expiratory and inspiratory scans by means of the relative lobar expansion. This model has been validated against SPECT [1].Objective To compare models of lobar ventilation from CT with 3He MRI using multi-modal image registration in a population of asthma patients.Methods 29 patients with moderate-to-severe asthma underwent breath-hold CT at TLC and FRC. CT was used to segment the lobes at FRC and TLC by identification of major fissures and these were used to calculate percentage lobar ventilation [1]. 1H and 3He MRI were acquired in the same breath at FRC+1L [2], and the 1H MRI to CT registration was applied directly to 3He MRI allowing direct comparison of lobar CT ventilation with 3He.Results 3He MRI was successfully warped to inspiration CT using the transform from the 1H MRI and CT registration. The mean absolute difference between CT and 3He MRI ventilation across lobes was 4.8% (mean±SD for each lobe: RUL+RML=6.1±4.6%; RLL=5.0±5.7%; LUL=4.0±4.1%; LLL=4.6±3.7%).Conclusion This study compares percentage lobar ventilation from CT models with a direct measure of gas ventilation using 3He MRI. In so doing we validate the CT ventilation model and demonstrate that multi-modal registration allows the regional interpretation of 3He MR images on top of the underlying anatomy of the CT.References [1]Radiol 2010;257:854-62 [2]NMR Biomed 2011;24:130-34.