[Preoperative staging of central bronchopulmonary cancer. X-ray CT-MRI-pulmonary digital subtraction angiography and surgery].

In order to evaluate the reliability of medical imaging methods in the assessment of mediastinal invasion by lung cancers, a prospective study was conducted in 30 patients undergoing preoperative computed tomography (CT), magnetic resonance imaging (MRI) and pulmonary digital subtraction angiography. MRI improved the sensitivity of detection of surgically confirmed mediastinal lymphadenopathy, but its specificity in relation to histological results was poor and identical to that of CT. In terms of extension to vascular structures, MRI and CT gave comparable results for the pulmonary artery and vein with two false positives for the pulmonary veins and left atrium with the two methods. MRI was found to be superior to CT for the detection of invasion of the aortic arch. Digital subtraction angiography is not as reliable as the other two modalities, particularly for extension to the pulmonary vein for which it was found to be technically inappropriate. By means of sagittal and frontal scans, MRI was therefore found to be more effective than CT for examination of the subcarinal region and aorto-pulmonary window. In contrast, the persistence of false positives with the two methods and the impossibility of distinguishing between inflammatory lymph nodes and neoplastic lymph nodes means that thoracotomy can never be contraindicated on the basis of the results of imaging alone.