Long-term sequelae of Farmer's lung disease in HRCT: a 14-year follow-up study of 88 patients and 83 matched control farmers.

The aim of this study was to compare high-resolution computed tomography (HRCT) findings of long-term farmer's lung (FL) patients and control farmers. We studied 88 FL patients and 83 matched control farmers with a mean follow-up time of 14 years. Emphysematous, fibrotic, and miliary changes were recorded by HRCT. The pattern of emphysema and location and distribution of other findings were evaluated in detail. Emphysema was found in 20 (23%) FL patients and in 6 (7%) controls (p=0.005). Recurrences of FL attacks increased (p=0.021) the risk of emphysema. Prevalence of fibrosis (17 vs 10%, p=0.16) and miliary changes (11 vs 4%, p=0.06) did not differ significantly in patients and controls. Among FL patients, emphysematous, fibrous, and miliary changes were more pronounced at the base than in the upper parts of the lung (p<0.02). In slice analysis, the pattern of emphysema was more polymorphous (p=0.001) and the distribution of fibrotic and miliary changes was more variable among FL patients than controls. Emphysema in HRCT is more common in FL patients than matched control farmers, and the occurrence is increased by recurrences of FL. Emphysematous, fibrous, and miliary changes in FL patients HRCT are multiform and predominate in the lower parts of the lung.