[Neoplastic invasion of the pulmonary arteries. Evaluation by MRI. Preliminary experience]

Bronchial tumors invading the mediastinum are no longer systematically regarded as inoperable. Curative surgery has produced a significant survival rate and led to the adaptation of the TNM classification. The degree of invasion of the pulmonary artery is a criterion of operability. The authors are trying to assess the role of MRI with regard to CT and DSA for the measurement of invasion. Their study deals with the prospective assessment of ten patients. The MRI examinations have been carried out with a 0.5 and 1.5 T supraconductive magnet (Philips Gyroscan). Cardiac gating has been used for acquisition. The planes of section are axial, transverse or oblique along the greater axis of the pulmonary arteries. CT examinations in 9-mm thick sections with and IV contrast injection demonstrate the contact of the tumor with the mediastinum. The digital angiograms have been taken with an intravenous injection into a vein of the bend of the elbow or into a femoral vein. Six cases have been verified at surgery. In all cases, the invasion predicted with MRI proved to be correctly assessed. In three cases, MRI provides additional information to the combined findings of CT and DSA. MRI is a good complement for the preoperative assessment of patients with large tumors invading the mediastinum but for which curative surgery is indicated.