Abstract
We investigated the correlation between CT and pulmonary function test results in five normal controls and ten patients with severe pulmonary emphsema. We used mean lung attenuation values (MLAV) and ΔEMP as the index of emphysematous change in CT. ΔEMP was defined as the ratio of the area (-960 Hounsfield Units- -1024HU) to the area (-774HU--1024HU). MLAV and ΔEMP were measured from histograms of the CT review. Mean MLAV in pulmonary emphysema was -947.1±9.3HU, and that in normal controls was -906.6±23.6HU. Mean ΔEMP in pulmonary emphysema was 50.0±9.9%, and that in normal controls was 18.8±13.0%. The data in pulmonary emphysema cases differed significantly from those in normal controls. Furthermore MLAV and ΔEMP had good correlation to VC, %VC, FEV1, FEV1/FVC, RV/TLC, %V25 and Raw. CT is an easier examination than pulmonary function test for patients, and can show the extent and the distribution of emphysematous area. In this study it is suggested that CT is a useful examination in severe pulmonary emphysema.
