Comparison of distribution of lung aeration measured with EIT and CT in spontaneously breathing, awake patients1.
BACKGROUND
Both Electrical Impedance Tomography (EIT) and Computed Tomography (CT) allow the estimation of the lung area. We compared two algorithms for the detection of the lung area per quadrant from the EIT images with the lung areas derived from the CT images.


METHODS
39 outpatients who were scheduled for an elective CT scan of the thorax were included in the study. For each patient we recorded EIT images immediately before the CT scan. The lung area per quadrant was estimated from both CT and EIT data using two different algorithms for the EIT data.


RESULTS
Data showed considerable variation during spontaneous breathing of the patients. Overall correlation between EIT and CT was poor (0.58-0.77), the correlation between the two EIT algorithms was better (0.90-0.92). Bland-Altmann analysis revealed absence of bias, but wide limits of agreement.


CONCLUSIONS
Lung area estimation from CT and EIT differs significantly, most probably because of the fundamental difference in image generation.
Department of Anesthesiology and Intensive Care Medicine, Klinikum Bremerhaven-Reinkenheide, Postbrookstr. 103, 27574 Bremerhaven, Germany.|Department of Anesthesia & Perioperative Care, San Francisco General Hospital, University of California San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA.|Anaesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany.
Oliver C
OC
Radke
Anaesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany.
Thomas
T
Schneider
Anaesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany.
Anja
A
Braune
Department of Anesthesia & Perioperative Care, San Francisco General Hospital, University of California San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA.|Department of Anesthesia and Intensive Care Medicine, Hôpital Européen Georges Pompidou, Université Paris 5 Descartes, Sorbonne Paris Cité, Paris, France.
Romain
R
Pirracchio
Drägerwerk AG & Co. KGaA, Moislinger Allee 53-55, 23558 Lübeck, Germany.
Felix
F
Fischer
Anaesthesiology and Critical Care Medicine, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany.
Thea
T
Koch
Electrical Impedance Tomography; Imaging; diagnostic imaging; ventilation