Gallium sixty-seven citrate imaging in coal workers' pneumoconiosis

Although nonspecific, pulmonary gallium (Ga ) imaging is a useful diagnostic study in many diseases. Positive (increased uptake) Ga imaging has been reported in radiographic silicosis and asbestosis. The purpose of this pilot study was to assess the use of Ga imaging as an indicator of lung reaction to retained coal dust in underground coal miners with and without radiographic coal workers' pneumoconiosis (CWP). Twenty-two coal miners with a minimum of 20 years of underground coal mining without other significant dust exposure or known pulmonary disease were studied. Eleven miners had radiographic CWP and eleven had normal chest radiographs. The eleven miners with CWP by chest x-ray (CXR) were found to have an increased diffuse uptake (positive) image over their lung fields. In five of eleven positive scans, increased activity was present in areas where no disease was noted on CXR. The eleven miners without CWP on CXR had normal scans. In conclusion, radiographic CWP is associated with increased Ga uptake (positive image). There is also a suggestion that the scan is more sensitive than the corresponding chest radiograph in affected miners. In addition, coal miners without CXR evidence of CWP have normal Ga uptake.