In Vivo MR Spectroscopy of Arbitrarily Shaped Voxels Using 2D-Selective RF Excitations Based on a PROPELLER Trajectory with Eliminated Side Excitations & Adapted Sampling Density Correction

Martin G. Busch¹, ², Jrgen Finsterbusch¹, ²

The recently presented 2D-selective RF excitations based on the PROPELLER trajectory suffer from residual side excitations caused by trajectory imperfections and limitations of the Voronoi diagram used to estimate the sampling density. Here, one of the refocusing RF pulses of a PRESS-based pulse sequence is used to eliminate the unwanted side excitations of each segment which completely avoids signal contributions from outside of the desired region-of-interest. With an appropriately adapted sampling density correction, arbitrarily shaped profiles can be excited at high spatial resolutions that are used to acquire MR spectroscopy of anatomically defined voxels in the living human brain.