Ventilation and perfusion imaging by electrical impedance tomography: a comparison with radionuclide scanning

Electrical impedance tomography (EIT) is a technique that makes it possible to measure ventilation and pulmonary perfusion in a volume that approximat es to a 2D plane. The possibility of using EIT for measuring the left-right division of ventilation and perfusion was compared with that of radionucli de imaging. Following routine ventilation (Kr-81m) and perfusion scanning ( Tc-99m-MAA), EIT measurements were performed at the third and the sixth int ercostal level in 14 patients with lung cancer. A correlation (r = 0.98, p < 0.005) between the left-right division for the ventilation measured with EIT and that with Kr-81m was found. For the left-right division of pulmonar y perfusion a correlation of 0.95 (p < 0.005) was found between the two met hods. The reliability coefficient (RC) was calculated for estimating the le ft-right division with EIT. The RC for the ventilation measurements was 94% and 96% for the perfusion measurements. The correlation analysis for repro ducibility of the EIT measurements was 0.95 (p < 0.001) for the ventilation and 0.93 (p < 0.001) for the perfusion measurements. In conclusion, EIT ca n be regarded as a promising technique to estimate the left-right division of pulmonary perfusion and ventilation.