Ventilation and perfusion scans in the preoperative assessment of bronchial carcinoma.

Ventilation (krypton -81m) and perfusion (technetium -99m) lung scans were obtained in a consecutive series of 21 patients shortly before thoracotomy for proven or suspected carcinoma of the bronchus. In most patients ventilation and perfusion were impaired equally and the scan abnormality corresponded to the bronchoscopic and radiological findings. Unexpectedly large defects in the perfusion scan were seen in three patients, all of whom had extensive neoplastic involvement of the mediastinum at thoracotomy, but 11 other patients had mediastinal involvement which was not suspected from the scan. Ventilation scanning was useful in the prediction of postoperative ventilatory capacity in two patients who underwent pneumonectomy. We conclude that ventilation and perfusion scans are not sensitive indicators of neoplastic involvement of the mediastinum but they are valuable for the prediction of postoperative lung function.