The relationship between pulmonary function tests, thorax HRCT, and quantitative ventilation-perfusion scintigraphy in chronic obstructive pulmonary disease

We have evaluated the relationship between pulmonary function tests (PFT), thorax high resolution computed tomography (HRCT) images and quantitative ventilation-perfusion (V/Q) scintigraphic studies in 16 male patients (mean age 65.6+/-5.5 years) with chronic obstructive pulmonary disease (COPD). The mean forced vital capacity (FVC) value of the patient group was 2352+/-642 mL (65.4+/-15.8%), whereas mean forced expiratory volume in one second (FEV1) was found to be 1150 +/- 442 mL (40.8+/-14.9%). The ratio of carbon monoxide diffusion capacity to alveolar ventilation (DLCO/VA) was 3.17+/-0.88 mL/min/mmHg/L, and the mean partial oxygen (PaO2) and carbon dioxide (PaCO2) pressures were 68.5+/-11.04 mmHg and 38.9+/-5.8 mmHg respectively. For each patient, thorax HRCT and V/Q scintigraphic images of both lungs were divided into upper, mid and lower zones during examination. Visual scoring for the assessment of emphysema on thorax HRCT were used and images were graded from mild to severe (<= 25%->= 76%). Emphysema scores were found to be higher on upper zones with accompanying lowest V/Q ratios. DLCO/VA, DLCO, total emphysema scores, and individual emphysema scores of the upper, mid and lower zones were found to be correlated. As a conclusion, it can be stated that emphysematous changes in COPD patients are more apparent in the upper lung zones, which also have the lowest V/Q ratios.