Kelvin Chow1, Ben Esch2, Mark Haykowsky3, Ian Paterson4, Richard Thompson1
1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada; 2Cardiovascular Physiology and Rehabilitation Laboratory, University of British Columbia, Vancouver, British Columbia, Canada; 3Physical Therapy, University of Alberta, Edmonton, Alberta, Canada; 4Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada
Non-rigid registration of serially acquired MRI lung images provides a direct method for quantifying lung ventilation with minimal user interaction. In-plane deformations are translated into local volume changes, which are combined with respiration rates to measure regional ventilation, and summed over the lungs to determine total lung ventilation. Simultaneous measurement of total ventilation over a large range of ventilation rates (3-35 liters/min) using gold standard spirometry correlated well with MRI rates (R2=0.88). Regional ventilation maps show significant differences (p<0.05) between ventilation in anterior (1915% volume increase) vs. posterior (3016%) lung regions, and a continuous chest-to-back gradient in all subjects.