OBJECTIVETo apply low-dose multi spiral computed tomography (MSCT) chest scans in the early diagnosis and differential diagnosis of pneumoconiosis.

METHODSOne hundred and twenty dust-exposed volunteers were examined by MSCT chest scans at conventional dose and low dose, and the results of conventional-dose scans were set as the gold standard. Comparative analysis was performed on the major CT findings and quality of post-processing images, including 1.5 mm and 5.0∼10.0 mm thick high -resolution reconstructed images, multiplanar reformat images, and maximum intensity projection images.

RESULTSOne hundred and twenty cases of small circular shadows, 36 cases of ribbon shadows in pulmonary parenchyma, 1 case of honeycombing shadow, and 13 cases of big shadows were all showed on low -dose MSCT. But 94 (95.9%) of 98 cases of interlobular septal thickening shadows and 98 (93.3%) of 105 cases of short branched shadows were detected on low-dose MSCT. There were no significant differences in display of the mentioned large and small shadows between low-dose scans and conventional-dose scans (P > 0.05). Eighty-five cases of small airway disease, 8 cases of pulmonary inflammatory lesions, and 47 cases of hilar and mediastinal lymph node swelling were all detected by MSCT. As for the 46 cases of emphysema, 38 (82.6%) were shown. The low-dose MSCT images of 1.5 mm thickness had more artifacts than those of other thickness. The radiation dose of low-dose MSCT was about 1/3-1/5 of that in the conventional-dose MSCT.

CONCLUSIONThere is no difference in display of pneumoconiosis between low-dose and conventional-dose MSCT chest scans. With lower radiation dose, low-dose MSCT can be applied in the diagnosis of pneumoconiosis.