Regional ventilation distribution in patients with scoliosis assessed by electrical impedance tomography: Is individual thorax shape required?

Background: Electrical impedance tomography (EIT) is a non-invasive non-radiological regional lung function measurement. The aim of the study was to examine the feasibility of assessing ventilation distribution with EIT in scoliosis patients using generic and individual thorax shape.

Methods: Eight subjects were measured with EIT before scoliosis surgery. Reconstructions with two different forward models were compared: the generic shape and the individual thorax shapes. Three EIT-based parameters measuring ventilation distribution were calculated: left lung to overall ratio, center of ventilation (CoV), global inhomogeneity index.

Results: EIT measurements were successfully conducted in all subjects. No statistical differences were found in the EIT-based parameters using the different reconstruction models. CoV based on the generic shape was significantly correlated to the main Cobb angle (r=-0.84, p < 0.01).

Conclusion: It was feasible to monitor regional ventilation distribution in scoliosis patients with EIT. Individual thorax shapes might not be required for reliable patient assessment in a clinical setting.