[Correlation of the perfusion scintigram with pulmonary functions in chronic obstructive pulmonary disease]

We carried out ventilation-perfusion scintigraphy and pulmonary function tests in 21 patients with chronic obstructive pulmonary disease. We used 99mTc-macroaggregate for perfusion scintigram and 133Xe gas for ventilation scintigram. We added the radioactivities of rebreathing phase and made lung volume image using computer. Regions of interest (ROIs) were derived from radioactivities in each image. ROIs on lung volume image included each whole lung and those on perfusion image included the areas which had relatively high radioactivity. We counted the area of ROIs on lung volume (L) and perfusion (P) images. Then we used the ratio of perfusion to lung volume (P/L) as a parameter of pulmonary perfusion. P/L had the significant correlations with the vital capacity, the actual FEV1.0, arterial oxygen partial pressure, diffusing capacity, RV/TLC and peak flow rate. These results suggested that P/L was a useful parameter of pulmonary perfusion in chronic obstructive pulmonary disease.