Abstract #1415

Segmented 2D-Selective RF Excitations with Weighted Averaging & Flip Angle Adaptation for MR Spectroscopy of Irregularly Shaped Voxel

Jrgen Finsterbusch^1,2, Martin G. Busch^1,2

¹Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; ²Neuroimage Nord, University Medical Centers Hamburg-Kiel-Lbeck, Hamburg-Kiel-Lbeck, Germany

A weighted averaging scheme with flip angle adaptation is presented and applied to single-line segments of a 2D-selective RF excitations based on a blipped-planar trajectory. Segments covering central k-space lines with significant signal contributions are averaged more often than outer segments with low flip angles and minor signal contributions. For compensation, these outer segments are acquired with a larger flip angle such that an unaltered signal contribution is obtained in a reduced number of shots. This improves the signal efficiency considerably as is demonstrated for MR spectroscopy of irregularly shaped, target-matched single voxel in the human brain in vivo.