3-D Lung Visualization Using Electrical Impedance Tomography Combined with Body Plethysmography

Abstract

Electrical impedance tomography (EIT) is a noninvasive, radiation-free imaging technique. It is used at the bedside for monitoring the regional lung ventilation and tidal volume distribution. Up to now, EIT data are reconstructed to 2-dimensional images. In this paper, a time-resolved 3-dimensional visualization of lung EIT data is presented.

Thorax EIT measurement was performed on one healthy volunteer. Series of measurements were recorded at 5 consecutive planes, started at the level of axilla towards caudal. The volunteer was asked to breathe at similar ventilation level during the measurements. Tidal volume (VT) and functional residual capacity (FRC) were measured at the same time with a modified body plethysmograph.

Three dimensional transient imaging of lung contour, volume distribution was implemented based on the series 2-D relative impedance measurements. Ventilation levels of the volunteer among different measurements were similar confirmed by body plethysmography (FRCpleth: 3.68 ± 0.09 L, VT: 0.93 ± 0.12 L; mean ± SD). The air distributions in the lungs during tidal breathing were visualized in 3-D.

We presented first steps to visualize the lung ventilation distribution in 3-D measured by EIT. This novel fast supporting method may provide better insight into lung disease and its progression as well as the acceleration of clinical acceptance of EIT.