Comparison of Image Based and Reconstruction Based Respiratory Motion Correction for Coronary MR Angiography

Abstract

Purpose: Respiratory motion correction has been shown to significantly reduce scan times for cardiac magnetic resonance angiography (MRA) while providing high quality images. Here, two commonly used methods, imaged based (IMC) and reconstruction based (RMC) respiratory motion correction, are compared regarding their dependency on motion estimation accuracy and final image quality.Methods: IMC and RMC are compared by estimating the motion from the same acquired data, using a non-Cartesian radial phase encoding acquisition. Simulations and in-vivo acquisitions in ten healthy volunteers are carried out. MRA images are reconstructed with IMC, RMC and a gold standard navigator-based respiratory gating (RG) approach. Achieved image qualities for these methods are compared quantitatively regarding visible vessel length and sharpness. Qualitative visual assessment is performed by two experts.Results: RMC led to significantly better image quality than IMC. RMC did not show a statistically significant difference compared to RG in terms of image quality while reducing scan times by 56%.Conclusion: RMC provides a similar image quality as the gold standard RG approach but almost halves the scan time and is independent of subjects’ breathing patterns. Clinical validation of RMC is now warranted as potential alternative to RG, providing high quality MRA in a short and predictable scan time.