Correlation among the indices of high-resolution computed tomography, pulmonary function tests, pulmonary perfusion scans and exercise tolerance in cases of chronic pulmonary emphysema

Background: Mismatched distribution of pulmonary blood flow is a common characteristic in emphysematous patients. But few reports have mentioned the relationships between the morphological changes in the lungs as assessed by high-resolution computed tomography (HRCT), pulmonary blood flow (PBF) scan and the indices of exercise tolerance. We investigated these relationships. Objective: Pulmonary function tests (PFT), HRCT, single photon emission computed tomography ((SPECT)-S-99m) and treadmill exercise tests were performed on emphysematous patients, and the correlations between these examinations were studied. Methods: We evaluated 20 patients (M 18, F 2, age 66 +/- 8.0 years). CT evaluation was performed according to the grade of emphysematous change. 99mSPECT was performed to evaluate mismatched PBF by the score method. The better flow of the middle lobe was selected to be the standard lobe for the basic PBF. That score was set to 1 when the blood flow was below 60 or above 140%. PBF between 60 and 140% was scored as 0. Results: FEV1(r= 0.648, p = 0.002) and VC (r = 0.767, p = 0.001) correlated significantly with VO2 peak. FEV1 (r = 0.667, p = 0.0018) correlated significantly with anaerobic threshold (AT). CT grade did not correlate with PBF mismatch score (r = 0.266, p = 0.3376). %VO2 peak did not correlate with CT grade (r = -0.467, p = 0.0689) or with mismatch PBF score (r = -0.327, p = 0.2377). Conclusions: HRCT and (SPECT)-S-99m were advantageous for detecting the progression of disease and emphysematous changes. However, the severity of anatomical emphysematous changes did not necessarily correlate with the indices of exercise tolerance and pulmonary function tests. Copyright (C) 2002 S. Karger AG, Basel.