Objective  To investigate the correlation between chest imaging manifestations and lung function changes in patients with occupational pneumoconiosis.

  Methods  A total of 130 patients with occupational pneumoconiosis were studied and each patient underwent chest-high kilovoltage (HKV), chest spiral CT and lung function examination at the same day. According to GBZ 70-2015 "Diagnosis of Occupational Pneumoconiosis", the chest imaging manifestations of each patient were comprehensively evaluated together with HKV and CT, and then the different imaging characteristics were analyzed and compared with the classification of pulmonary function.

  Results  HKV combined with CT identified more clearly of the q-typed small shadow, small shadow aggregation, pleural thickening, and lymph node enlargement, compared with HKV alone(P < 0.05). There was a positive correlation between imaging grading and pulmonary function grading and the abnormal rate of pulmonary function in pneumoconiosis patients(G=0.726, P < 0.01;r_s=0.640, P < 0.01). The patients with higher overall density and/or more distribution of lung tissue of small shadows had more severely damage of lung function(P < 0.05). The larger the diameter(or width)of the shadow, the worse the lung function(r_s=0.410, P < 0.01). The patients with small shadow aggregates and/or large shadow manifestations had higher lung function grade than patients with only small shadows(P < 0.05). There was a difference of lung function among patients with different small shadow patterns(P < 0.01), and pneumoconiosis patients with small irregular shadows had worse lung function.

  Conclusions  Patients with occupational pneumoconiosis had different degrees of lung function impairment with different imaging characteristics, and the more significant the imaging changes, the more severe the lung function impairment.