[Assessment of differential lung function by electrical impedance tomography].
OBJECTIVE
To compare unilateral lung function estimated by 2 methods: electrical impedance tomography (EIT) and ventilation-perfusion lung scintigraphy.


METHODS
This prospective clinical study was carried out in the pulmonary function laboratory of a general hospital. Twenty patients diagnosed with lung cancer (17 men and 3 women, ranging in age from 25 to 77 years) who were candidates for lung resection underwent ventilation-perfusion lung scanning breathing a radioactive gas. Differential lung function was estimated based on images taken at 2 intercostal spaces in which ventilation and perfusion were represented by changes in bioelectrical impedance. Each lung's contribution to overall respiratory function was also calculated based on scintigraphy.


RESULTS
The right lung contributed a mean (SD) of 54% (9%) of ventilation (range, 32%-71%) according to EIT. Scintigraphy similarly estimated the right lung's contribution to be 52% (10%) of total ventilation (range, 31%-80%) and 50% (9%) of perfusion (range, 37%-71%). The difference between the 2 estimates was not significant (t test), and the correlation coefficients between them were r=0.90 for ventilation and r=0.72 for perfusion (P< .05 in both cases). The analysis of agreement showed that the mean difference between the methods was 1.9% (95% confidence interval [CI], 10.5% to -6.8%) for ventilation and 3.4% (95% CI, 17.1% to -10.3%) for perfusion.


CONCLUSIONS
EIT is able to estimate differential lung function as accurately as ventilation-perfusion scintigraphy.
de Lema
J Bruno
JB
Unitat de Funció Pulmonar, Departament de Pneumologia, Hospital de la Santa Creu i Sant Pau, Facultat de Medicina, Universitat Autònoma de Barcelona, Barcelona, España.
Serrano
Ernesto
E
Feixas
Teresa
T
Calaf
Núria
N
Camacho
María Valle
MV
Riu
Pere J
PJ
Casan
Pere
P
D000328:Adult; D000368:Aged; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011877:Radionuclide Imaging; D012129:Respiratory Function Tests / Q000379:methods