Regional ventilation by electrical impedance tomography: a comparison with ventilation scintigraphy in pigs.
OBJECTIVE
The validation of electrical impedance tomography (EIT) for measuring regional ventilation distribution by comparing it with single photon emission CT (SPECT) scanning.


METHODS
Randomized, prospective animal study.


METHODS
Animal laboratories and nuclear medicine laboratories at a university hospital.


METHODS
Twelve anesthetized and mechanically ventilated pigs.


METHODS
Lung injury was induced by central venous injection of oleic acid. Then pigs were randomized to pressure-controlled mechanical ventilation, airway pressure-release ventilation, or spontaneous breathing.


RESULTS
Ventilation distribution was assessed by EIT using cross-sectional electrotomographic measurements of the thorax, and simultaneously by single SPECT scanning with the inhalation of (99m)Tc-labeled carbon particles. For both methods, the evaluation of ventilation distribution was performed in the same transverse slice that was approximately 4 cm in thickness. The transverse slice then was divided into 20 coronal segments (going from the sternum to the spine). We compared the percentage of ventilation in each segment, normalized to the entire ventilation in the observed slice. Our data showed an excellent linear correlation between the ventilation distribution measured by SPECT scanning and EIT according to the following equation: y = 0.82x + 0.7 (R(2) = 0.92; range, 0.86 to 0.97).


CONCLUSIONS
Based on these data, EIT seems to allow, at least in comparable states of lung injury, real-time monitoring of regional ventilation distribution at the bedside.
Hinz
José
J
Department of Anesthesiology, Emergency, University of Göttingen, Göttingen, Germany. mail@josehinz.de
Neumann
Peter
P
Dudykevych
Taras
T
Andersson
Lars Goran
LG
Wrigge
Hermann
H
Burchardi
Hilmar
H
Hedenstierna
Goran
G
D000818:Animals; D002244:Carbon; D017097:Electric Impedance; D007726:Krypton; D008168:Lung / Q000000981:diagnostic imaging* / Q000502:physiology*; D012123:Pulmonary Ventilation; D012121:Respiration, Artificial; D013552:Swine; D014054:Tomography / Q000295:instrumentation / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon
D007726:Krypton; D002244:Carbon