Qualitative And Quantitative Multi-spiral CT Evaluation From Coal Miners And CWP Patients

Objective To explore the values of early detection in micronodules, nodule coalescence and emphysema of CWP from coal miners with and without radiographic CWP evidence by comparing with the images between CT, HRCT and radiographic images.Methods Two hundred male subjects were included in the present study and divided into three groups: health controls (37), health coal miners (67) and CWP patients (96). All subjects underwent continous volumetric scanning by multi-spiral CT (MSCT) and lung function test. CT and HRCT images were reconstructed on the basis of volumetric data of MSCT. Lung parenchyma nodule shape and profusion, nodule coalescence, mean lung attenuation and emphysema index (EI) were evaluated on the radiographic, CT and HRCT scans. Comparison about lung function, pulmonary emphysema and morphologic changes on combined reading of CT and HRCT scans among and between groups were analysed with ANOVA, student t test andχ2 tests, as appropriate. The relationships between lung function parameters and morphological manefastations of CWP on radiographs as well as combined reading of CT and HRCT scans were evaluated by Spearman rand correlations.Results(1) Good agreement was reached between radiographs and combined reading of CT and HRCT scans for lung parenchyma opacity profusion category of CWP (Kappa=0.724, p<0.01). CT and HRCT scans for opacity category was more accurate. Significantly higher frequency of emphysema was observed on combined reading of CT and HRCT scans than that on radiographs(χ2=26.423, p<0.01). CT and HRCT scans were more sensitively in detecting nodular coalescence than radiographic.(2) The mean lung attenuation was significantly increased in health coal miner and CWP groups than that in health control group (ANOVA F=9.713, p<0.01). Mean lung attenuation of coal miners without CWP, who were radiographic negative but CT and HRCT positive evaluation were significantly increased than that of health controls(p<0.01). However lung function parameters in these subgroups have not significant difference. Mean lung attenuation in grade I of CWP with radiographic simple but CT and HRCT complex subgroup were significantly increased than that with radiographic simple and CT and HRCT simple subgroup(p<0.01), meanwhile a variety of lung function parameters were reduced. (3) Spearman rand correlation showed that CT and HRCT scans for lung parenchyma opacity profusion category of CWP were closely associated with many lung function parameters, including: negative correlations with FEV1.0, FEV1.0/FVC, FEF50, MVV and TLC (r=-0.159, -0.155, -0.204, -0.203 and -0.209, p<0.05 or p<0.01). Emphysema index (EI) was associated with many lung function parameters, including: negative correlations between EI and DLco (r=-0.309, p<0.05), and positive correlation between EI and RV (r=0.327, p<0.05). Mean lung attenuation was closely associated with many lung function parameters, including: negative correlations with FVC, FEV1.0, TLC and RV (r=-0.184, -0.208, -0.207 and -0.203, p<0.05 or p<0.01).(4) Multiple linear regression analysis showed that intensive classification of lung parenchyma opacity profusion category in pneumoconiosis and mean lung attenuation were the major factors affecting in the VC, FVC, TLC. EI was the major factor affecting the RV. Mean lung attenuation affected in a variety of lung function parameters (except FEV1.0 and MVV). FEV1.0 and MVV was mainly affected by mean lung attenuation. Through the help of quantitative indicators analysis, we may predict the lung function of early pneumoconiosis.Conclusion1. CT and HRCT images reconstructed on the basis of volumetric data of MSCT were demonstrated earlier than radiographic in diagnosing micronodules, nodule coalescence and emphysema of CWP from coal miners with and without radiographic CWP evidence.2. CT mean lung attenuation may be a sensitive quantitative indicator of lower-grade pneumoconiosis assessment. Emphysema index could reflect nodule coalescence and the extent of Lung parenchyma damage.3. CT and HRCT scans could reflect the pulmonary function of lower-grade pneumoconiosis in some extent.