[Longitudinal follow-up evaluation of pulmonary emphysema using high-resolution Computed Tomography (HRCT) study and...

To evaluate the usefulness of HRCT in the identification of longitudinal progression of emphysema and to establish the sensitivity of HRCT compared with functional tests.

15 ex-smokers with chronic obstructive lung disease were studied, using two consecutive HRCT examinations (t1 and t2); emphysema was evaluated by HRCT visual score and, at the same time, pulmonary function tests.

As a whole, the extension of emphysema with HRCT presented a good correlation with Tiffeneau index (IT). At t1 a significant correlation between HRCT and IT was almost reached; it was achieved between HRCT and PaCO2, FEV1 and IT. At t2, there was a significant correlation between HRCT and IT, FEV1 and IT, FEV1 and PaO2, FEV1 and PaCO2, IT and PaO2. In the interval between t1 and t2 there was a significant worsening of HRCT visual score and IT, with no modification of FEV1, PaO2 and PaCO2. The change in HRCT visual score had a significant correlation with FEV1.

HRCT is able not only to identify and quantify anatomic emphysema, but also to evaluate progression of the disease. In the middle-short term anatomic emphysema worsens significantly and visual score HRCT is more sensitive than functional tests for longitudinal evaluation because emphysematous destruction is faster than decline in function. Furthermore emphysematous destruction in smokers progresses even after smoking cessation. The usefulness of combining HRCT with functional tests in the follow-up remains to be established. Longitudinal examination by HRCT could allow us to identify the smokers that tend to develop earlier and more seriously the symptoms of chronic obstructive lung disease.