Beat-to-beat respiratory motion correction with near 100% efficiency: a quantitative assessment using high-resolution coronary artery imaging

This study quantitatively assesses the effectiveness of retrospective beat-to-beat respiratory motion correction (B2B-RMC) at near 100% efficiency using high-resolution coronary artery imaging. Three-dimensional (3D) spiral images were obtained in a coronary respiratory motion phantom with B2B-RMC and navigator gating. In vivo, targeted 3D coronary imaging was performed in 10 healthy subjects using B2B-RMC spiral and navigator gated balanced steady-state free-precession (nav-bSSFP) techniques. Vessel diameter and sharpness in proximal and mid arteries were used as a measure of respiratory motion compensation effectiveness and compared between techniques. Phantom acquisitions with B2B-RMC were sharper than those acquired with navigator gating (B2B-RMC vs. navigator gating: 1.01 +/- 0.02 mm(-1) vs. 0.86 +/- 0.08 mm(-1) P <.05). In vivo B2B-RMC respiratory efficiency was significantly and substantially higher (99.7%+/- 0.5%) than nav-bSSFP (44.0%+/- 8.9%, P <.0001). Proximal and mid vessel sharpnesses were similar (B2B-RMC vs. nav-bSSFP, proximal: 1.00 +/- 0.14 mm(-1) vs. 1.08 +/- 0.11 mm(-1), mid: 1.01 +/- 0.11 mm(-1) vs. 1.05 +/- 0.12 mm(-1); both P=not significant [ns]). Mid vessel diameters were not significantly different (2.85 +/- 0.39 mm vs. 2.80 +/- 0.35 mm, P=ns), but proximal B2B-RMC diameters were slightly higher (2.85 +/- 0.38 mm vs. 2.70 +/- 0.34 mm, P <.05), possibly due to contrast differences. The respiratory efficiency of B2B-RMC is less variable and significantly higher than navigator gating. Phantom and in vivo vessel sharpness and diameter values suggest that respiratory motion compensation is equally effective. (c) 2011 Elsevier Inc. All rights reserved.