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Free breathing 3D balanced FFE coronary magnetic resonance angiography with prolonged cardiac acquisition windows and intra‐RR motion correction

A shortcoming of today's coronary magnetic resonance angiography (MRA) is its low total scan efficiency (<5%), as only small well‐defined fractions of the respiratory (50%) and cardiac (10%) cycle are used for data acquisition. These precautions are necessary to prevent blurring and artifacts related to respiratory and cardiac motion. Hence, scan times range from 4 to 9 min, which may not be tolerated by patients. To overcome this drawback, an ECG‐triggered, navigator‐gated free breathing radial 3D balanced FFE sequence with intra‐RR motion correction is investigated in this study. Scan efficiency is increased by using a long cardiac acquisition window during the RR interval. This allows the acquisition of a number of independent k‐space segments during each cardiac cycle. The intersegment motion is corrected using a self‐guided epicardial fat tracking procedure in a postprocessing step. Finally, combining the motion‐corrected segments forms a high‐resolution image. Experiments on healthy volunteers are presented to show the basic feasibility of this approach. Magn Reson Med 53:719–723, 2005. © 2005 Wiley‐Liss, Inc.