[Clinical studies for usefulness of Gd-DTPA enhanced MRI in lung cancer]

To evaluate utility of Gd-DTPA enhanced MRI (Gd-MRI) in lung cancer, Gd-MRI was performed in 69 cases. 1) Viable tumor was strongly enhanced, necrosis in the tumor, however, was not enhanced on Gd-MRI. Enhanced patterns of Gd-MRI were divided into 3 types, however there was little correlation between the enhancement patterns and histologic types. 2) In serial scan studies of 15 cases, the signal intensity of the tumor reached the peak 3 minutes to 10 minutes after Gd-DTPA administration, and after that the signal intensity decreased gradually. 3) In 23 of 27 (85%) hilar lung cancer cases, Gd-MRI could differentiate the tumor from the peripheral obstructive pneumonia or atelectasis. In 18 of these 23 cases, the peripheral lung disease showed higher intensity than the tumor. 4) In Gd-MRI of pulmonary nodules less than 3 cm in diameter, lung cancers (n = 13) were more strongly enhanced than tuberculomas (n = 5) (p less than 0.001). Based on these data, Gd-MRI was helpful for detecting tumor necrosis and tumor extension on hilar lung cancer with peripheral lung disease. Moreover Gd-MRI may become a feasible diagnostic method for pulmonary nodules.