Comparison of gradient-echo and steady state free precession sequences for 3D-navigator MR angiography of coronary arteries

Aim: Purpose of our study was to compare the image quality of 3D-navigator steady state free precession (SSFP) and gradient echo (GE) sequences for magnetic resonance coronary angiography (MRCA) in volunteers and patients. Methods: Following informed consent 8 volunteers and 12 patients were included into this study. In all subjects a 3D navigator MRCA of the right and the left coronary artery was performed with a SSFP (TR 3.9 ms, TE 1.7 ms, FA 65degrees, bandwidth 540 Hz) and a GE (TR 5.8 ms, TE 2.2 ms, FA 25degrees, bandwidth 200 Hz) sequence using a 1.5T-MR-System (Magnetom Sonata, Siemens Erlangen). The slice thickness was 1.5 mm and the in-plane resolution was 0.9 x 0.7 mm(2) for all measurements. Results: The blood pool showed a significantly (p < 0.01) higher signal intensity on SSFP images (147 +/- 36) compared to GE images (103 36). Although noise increased with SSFP (9.3 +/- 1.4 versus 5.3 +/- 0.9), the contrast-to-noise ratio between myocardium and the coronaries was significantly (p < 0.01) higher on SSFP images (7.8 +/- 3.7 versus 3.4 +/- 3.3). The CNR between the coronaries and the epicardial fat showed no significant differences (12 +/- 5 versus 13 +/- 4). Conclusion: The 3D-navigator SSFP sequence is a promising new technique for MRCA which improves the contrast between the coronaries and the myocardium and shortens the data acquisition compared to gradient-echo imaging.