Three-dimensional electrical impedance tomography (EIT) to study regional ventilation/perfusion (V/Q̇ ) ratios in anesthetized pigs

Abstract

Abstract This study aimed to develop a 3D method for assessing V/Q̇ ratios in a pig model of hemodynamic perturbations using electrical impedance tomography (EIT). In order to evaluate whether the physiological coherence of changes in EIT-derived V/Q̇ ratios, global EIT-derived V/Q̇ mismatch were compared with global gold-standards. The study found regional heterogeneity in the distribution of V/Q̇ ratios in both the ventrodorsal and craniocaudal directions. Although global EIT-derived indices of V/Q̇ mismatch consistently underestimated both low and high V/Q̇ mismatch compared to global gold standards, the direction of the change was similar. We have made the software available at no cost for other researchers to use. Future studies should compare regional V/Q̇ ratios determined by our method against other regional, high-resolution methods such as SPECT or PET scan.