Multiphase ECG-triggered 3D contrast-enhanced MR angiography: Utility for evaluation of hilar and mediastinal invasion of bronchogenic carcinoma

The purpose of this study was to evaluate the usefulness of cardiac synchro nized magnetic resonance angiography [electrocardiographically (ECG)-trigge red MRA] for Improving Image quality and detection of hilar and mediastinal Invasion of bronchogenic carcinoma. Fifty patients, suspected of having hi lar or mediastinal invasion of bronchogenic carcinoma, underwent contrast-e nhanced computed tomography and MR Imaging including conventional and ECG-t riggered MRA. Twenty patients subsequently also underwent surgical resectio n. Vascular enhancement-to-background ratio (VBR), vascular enhancement-to- tumor ratio (VTR), signal-to-noise ratio (SNR), contrast-to-noise ratio (CN R) and image quality scores of thoracic vessels obtained with both MRA tech niques were determined and compared. In addition, the diagnostic accuracy o f tumor invasion of pulmonary vessels was compared. VBRs and VTRs of both M RA techniques were not significantly different. ECG-triggered MRA significa ntly improved SNRs and CNRs (P < 0.05). Two readers judged that overall Ima ge quality of ECG-triggered MRA was better than that of conventional MRA (k appa greater than or equal to 0.41). In conclusion, ECG-triggered MRA impro ves the image quality and the detection of hilar and mediastinal invasion o f bronchogenic carcinoma. (C) 2001 Wiley-Liss, Inc.