Perfusion lung scan patterns in 100 patients with bronchogenic carcinoma.

The relationship between size of the perfusion defect as seen by perfusion lung scan (PLS) and size of the mass lesion as seen radiologically was correlated with the presence of regional adenopathy in 100 consecutive patients with bronchogenic carcinoma. All patients underwent scanning before open thoracotomy or mediastinotomy and had histologic documentation of the disease. Each perfusion lung scan was classified as follows: (1) perfusion defect larger than the mass lesion. (2) perfusion defect of the same size as the mass lesion, or (3) no focal defect seen. Among patients with a larger perfusion defect 84 per cent were found to have regional lymph node involvements, whereas among patients in whom a larger defect was not present only 23 per cent had such extensions of the disease.