Exploration of the early detection of lung parenchyma micronodules, nodule coalescence and emphysema by CT and HRCT in coal miners with and without coal-worker's pneumoconiosis evidence

Abstract

To explore the sensitivity and accuracy of CT and HRCT in early detection of coal-worker's pneumoconiosis (CWP) associated micronodules, nodule coalescence and emphysema from coal miners with and without radiographic CWP evidence. Continuously Thorax-Vol. CT scanning and High resolution CT scanning were performed on 113 coal miners with or without radiographic CWP evidence and 37 health controls by the use of Multi Spiral Computed Tomography (MSCT). The CT and HRCT images were evaluated for lung parenchyma opacity profusion category, nodule coalescence, emphysema index and mean lung attenuation, and then compared with that on radiographs. Good agreement for CWP associated opacity profusion grading was achieved between radiographs and CT scans (Kappa = 0.771). The sensitivity of CT and HRCT were 98.70% for CWP diagnosis when compared with radiographs. 8 (22.22%) cases out of 36 radiographic CWP negative coal miners were categorized as grade 1 opacity profusion in consistent with CWP on CT and HRCT scans, and 26 (35.62%) cases out of 73 radiographic grade 1-2 CWP patients were detected to have at least grade 3 nodular profusion on CT and HRCT scans. Among 113 coal miners, 36 (31.86%) were recognized as emphysema positive on CT; whereas only 7 (6.19%) on radiographs. According to CT opacity profusion grading, mean lung attenuation in coal miners with grade 1-2 opacity profusion classification was significantly increased than that in health control, CWP negative coal miner and grade 4 opacity profusion groups (F1 = -45.73, F2 = -23.00 and F3 = 52.72, P < 0.01 and P < 0.05). CT and HRCT acquired from MSCT showed high sensitive and accurate for the early detection of micronodules, nodule coalescence and emphysema in coal miners. It could be used as semi-quantitative and quantitative method in early diagnosis of CWP and its complications.