Respiratory Self-Gated Multiple Gradient Recalled Echo Sequence for Free-Breathing Abdominal R*2 Mapping

Abdominal effective transverse relaxation rate (R*(2)) mapping is critical for a wide range of applications. However, respiratory motion can lead to significant image quality deterioration and R*(2) overestimation. For this work, we explored the feasibility of combining respiratory self-gating techniques with a multiple gradient-recalled echo sequence for free-breathing abdominal R*(2) measurements. In a series of eight normal volunteers, respiratory self-gated-multiple gradient-recalled echo methods effectively avoided motion artifacts to produce quantitative R*(2) measurements in liver, spleen, and kidneys that were comparable to R*(2) measurements produced while breath-holding. Respiratory self-gated-multiple gradient-recalled echo methods demonstrated the potential to avoid the need for breath-holding during abdominal R*(2) mapping. For clinical application, respiratory self-gated-multiple gradient-recalled echo approaches could be particularly useful for R*(2) measurements in those patients unable or unwilling to sustain sufficiently long breath-holds to avoid motion artifacts. Magn Reson Med 66:207-212, 2011. (C) 2011 Wiley-Liss, Inc.