MR angiography: clinical applications in thoracic surgery

MR angiography (MRA) is a promising completion of MR imaging in the preoperative assessment of pulmonary and mediastinal tumours. Scan acquisition was done by sequential FLASH 2D angiograms (TR = 30 ms, TE = 10 ms, FA = 30 ), one section per breathhold, section thickness 5 mm with 1 mm overlap between sequential sections. An automated control procedure allowed individual continuation of the examination. Postprocessing by a maximum-intensity-projection algorithm using angiograms of interest (AOI) resulted in 3D reconstructions illustrating vascular anatomy and avoiding superimposition. This technique was evaluated in a prospective study of 15 patients with malignant intrathoracic tumours. The results were validated by conventional angiographic procedures such as pulmonary angiography, digital subtraction angiography or cavography. Complementing spin-echo (SE) imaging, MRA provided diagnostic information about vessel displacement, stenosis and perfusion defects due to space-occupying lesions. Thus, MRA was helpful in planning thoracic surgery. (orig.)