Correlation of High Resolution Computed Tomography Findings and Respiratory Function Tests in Chronic Obstructive Pulmonary Disease

Chronic obstructive lung disease (COPD) is a major cause of chronic morbidity and mortality throughout the world. For the diagnosis and assessment of COPD, respiratory function tests (RFT), arterial blood gas (ABG) and diffusing capacity (DC) measurements are corner stones. Currently, high resolution computed tomography (HRCT) has already been used to detect severity, extention of the paranchimal destruction and anatomic distribution of the disease. In this study, the purpose is to analyze correlation between HRCT and RFTs in diagnosis of COPD. Thirty clinically stable patients with chronic pulmonary disease were exposed to HRCT scanning after carrying out their RFT, DC and ABG. Twenty five were men and five were women. The mean age was 63.27 year (40-75). Qualitative evaluation based on visual scoring method in HRCT. Our patients were distinct two major groups (chronic bronchitis (19/30) and emphysema (11/30)). When we compared all patients without made two main group, there were highly significant negative correlation between indexes of airflow obstruction (FEV1 %, L, p<0.001; FEF25-75 %, L/sec and PEF %, p <0.005) and COPD stage. In emphysematous group we found highly significant correlation between visual score and disease stage (p<0.001); also we found very strong correlation between visual score and DLCO (mmol/kPa. sn,%), DLCO/VA (DLCO/L,%) measurements (p<0.001). In two patients emphysematous changes were demonstrated in HRCT without spirometric or other physiologic measurement abnormality. With these values, we conclude that clinical practice HRCT demonstrate morphological changes in a stage before symptoms develop in emphysematous patients.