Ventilation-perfusion lung scanning in patients detected by a screening program for early lung carcinoma.

Ventilation-perfusion (V-P) lung scans obtained in 114 patients in screening program for the early detection of lung cancer were reviewed, and abnormalities were correlated with radiographic and surgical findings. Eighty-seven patients eventually had a tissue diagnosis of carcinoma; 65 (75%) had a perfusion defect and 56 (67%) had a ventilation abnormality at the tumor site. Lobar or segmental perfusion abnormalities were present at the tumor site in two of 13 patients whose lung cancer could not be localized by chest radiographs. However, 12 of these 13 patients and 54% of those with radiographically visible lesions had perfusion abnormalities in other lung regions. Twenty-seven patients with suspected carcinoma who were subsequently proved to have benign lesions had V-P abnormalities similar to those in patients with lung cancer. Thus, no pattern of V-P abnormalities similar to those in patients with lung cancer. Thus, no pattern of V-P abnormalities allowed lung cancer in this screened population to be...