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 synchronized magnetic resonance angiography [electrocardiographically (ECG)-triggered MRA] for improving image quality and detection of hilar and mediastinal invasion of bronchogenic carcinoma. Fifty patients, suspected of having hilar or mediastinal invasion of bronchogenic carcinoma, underwent contrast-enhanced computed tomography and MR imaging including conventional and ECG-triggered MRA. Twenty patients subsequently also underwent surgical resection. Vascular enhancement-to-background ratio (VBR), vascular enhancement-to-tumor ratio (VTR), signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image quality scores of thoracic vessels obtained with both MRA techniques were determined and compared. In addition, the diagnostic accuracy of tumor invasion of pulmonary vessels was compared. VBRs and VTRs of both MRA techniques were not significantly different. ECGtriggered MRA signficantly improved SNRs and CNRs (P < 0.05). Two readers judged that overall image quality of ECG-triggered MRA was better than that of conventional MRA (κ ≥ 0.41). In conclusion, ECG-triggered MRA improves the image quality and the detection of hilar and mediastinal invasion of bronchogenic carcinoma.