[A study of chest X-ray classification of farmer's lung--correlation between X-ray pattern and background factors]

Patients with farmer's lung were classified into five groups according to their chest X-ray pattern, and the background of each group was studied with respect to stage, severity, and prognosis. Type I group, which has fine nodular shadows on chest X-ray, showed a significantly high percentage of lymphocytes in BAL cells (p less than 0.01). Type V group, which has irregular patchy shadows on chest X-ray, showed increased peripheral WBC counts, increased CRP score, and decreased PaO2 compared to the other groups. Type II, III, and IV groups, which are characterized by combined X-ray patterns such as nodular shadows, ring-like shadows, and irregular pulmonary markings, had no specific background features according to our study. Our results suggest that type I and type V groups are likely to represent acute phase and severe phase, respectively. We could not identify any significant factors indicative of chronic disease in terms of restrictive and diffusion impairment of pulmonary function tests and pathologic findings obtained by TBLB. The chest X-ray classification we proposed is useful for the diagnosis of the acute and severe stages of farmer's lung.