3D motion adapted gating (3D MAG): a new navigator technique for accelerated acquisition of free breathing navigator gated 3D coronary MR-angiography

This study aimed to evaluate the influence of a new navigator technique (3D MAG) on navigator efficiency, total acquisition time, image quality and diagnostic accuracy. Fifty-six patients with suspected coronary artery disease underwent free breathing navigator gated coronary MRA (Intera, Philips Medical Systems, 1.5 T, spatial resolution 0.9x0.9x3 mm(3)) with and without 3D MAG. Evaluation of both sequences included: 1) navigator scan efficiency, 2) total acquisition time, 3) assessment of image quality and 4) detection of stenoses > 50%. Average navigator efficiencies of the LCA and RCA were 43 +/- 12% and 42 +/- 12% with and 36 +/- 16% and 35 +/- 16% without 3D MAG (P < 0.01). Scan time was reduced from 12 min 7 s without to 8 min 55 s with 3D MAG for the LCA and from 12 min 19 s to 9 min 7 s with 3D MAG for the RCA (P < 0.01). The average scores of image quality of the coronary MRAs with and without 3D MAG were 3.5 +/- 0.79 and 3.46 +/- 0.84 (P > 0.05). There was no significant difference in the sensitivity and specificity in the detection of coronary artery stenoses between coronary MRAs with and without 3D MAG (P > 0.05). 3D MAG provides accelerated acquisition of navigator gated coronary MRA by about 19% while maintaining image quality and diagnostic accuracy.