Lung perfusion scanning in coal workers pneumoconiosis.

Thirty-seven miners and ex-miners were studied clinically, physiologically, and by lung perfusion scanning. All 14 with complicated pneumoconiosis had avascular zones in relation to conglomerate masses and bullae. A fissure sign related to nodules and emphysematous bullae was present in one. There were several reasons for assuming that avascular zones were due to vascular obliteration rather than intrapulmonary shunting. Among 21 miners with simple pneumoconiosis, only 2 had avascular zones related to nodules rather than to other causes of hypoperfusion. The results of these studies accord well with previous pathologic studies of the pulmonary vasculature in pneumoconiosis.