Comparison of high-resolution computed tomography with pulmonary function testing in symptomatic smokers

Abstract

Purpose: To compare high-resolution computed tomography (HRCT) of lungs with pulmonary function in smokers diagnosed with emphysema.

Material and method: The authors retrospectively reviewed 17 patients with a history of smoking and dyspnea, who underwent HRCT of the lungs and pulmonary function testing. HRCT scores were determined and compared to pulmonary function (FEV1, FEV1/FVC, and DLCO).

Results: The HRCT of all 17 patients (17/17; 100%) were typical of centrilobular emphysema; with a mean score of 12.88+/-9.18 (range, 4 to 34). Decreased FEV1 (<80% predicted) was found in 8 patients (47%), decreased FEV1/FVC (<70% predicted) in 13 patients (76%) and decreased DLCO (<80% predicted) in 3 patients (18%). The severity of emphysema revealed by HRCT was inversely correlated with the pulmonary function test: DLCO (r=-0.842, p=0.000) and FEV1 (r=-0.597, p= 0.011), but not FEV1/FVC (r=-0.400, p=0.112).

Conclusion: HRCT allows detection of emphysema in symptomatic smokers even when pulmonary function appears to be normal. The greater the involvement of emphysema revealed by the HRCT, the poorer the pulmonary function. The authors, therefore, conclude that HRCT is the most sensitive modality for diagnosing early emphysema in smokers with dyspnea.