Exploration of the Jacobian Determinant in Voxel-wise Lung Ventilation (VOLVE) Analysis to Assess Local Expansion in COPD

Motivation: To develop 1H MRI methods to study dynamical lung expansion as a marker of lung function. Goal(s): To collect free breathing 1H MRI over the respiratory cycle and investigate the feasibility of using the Jacobian determinant of the registered images for dynamic functional assessment of local expansion, instead of the signal intensity as is used in FD/PREFUL analyses. Approach: Voxel-wise lung ventilation (VOLVE) analysis using the timecourse of deformation based Jacobian determinant to assess the ventilation correlation coefficient. Results: Significant differences in the Jacobian-derived correlation coefficient between healthy and COPD groups indicating differences in local expansion which may provide a lung functional marker. Impact: The Jacobian determinant obtained from registering free breathing 1H lung MRI images provides a metric of local expansion related to respiratory phase, which is sensitive to lung disease. This motivates future work to combine signal intensity-based and deformation-based functional assessments.