What does coal mine dust lung disease look like? A radiological review following re-identification in Queensland

Coal mine dust lung disease (CMDLD), including the pneumoconioses, dust-related diffuse fibrosis (DDF) and chronic obstructive pulmonary disease (COPD), are occupational lung diseases attributed to respirable coal mine dust. Following the re-identification of CMDLD in Queensland in 2015, we undertook a case series to understand their radiological presentation.

Chest radiographs and high-resolution computed tomography (HRCT) were retrospectively reviewed for 79 male individuals diagnosed by a respiratory physician with a CMDLD since 2015. Radiological findings were characterised as per the International Labour Office Classification System (ILO system) and the International Classification of HRCT for Occupational and Environmental Respiratory Diseases (ICOERD).

Subjects with pneumoconiosis (n = 56) demonstrated widespread opacities with bilateral upper zone predominance. The majority of the lung was impacted, with 72% and 79% of zones demonstrating opacities on chest radiograph and HRCT, respectively. Most pneumoconiosis subjects (71%) demonstrated ILO category 1 disease, while 29% had advanced disease (ILO grades ≥ 2/1). A high proportion (81%) of pneumoconiosis subjects demonstrated at least one radiological feature associated with exposure to respirable crystalline silica (RCS). DDF subjects (n = 5) had radiologically severe disease (mean ILO 2/1) with lower zone-predominant irregular opacities. Widespread emphysema, with no zone dominance, was the key radiological feature in those with COPD (n = 18).

Radiological findings of particular interest included the high burden of opacities observed and the presence of RCS-associated features in the majority of subjects. Radiologists are at the front line in occupational lung disease screening/diagnosis and must be aware of the imaging spectrum.