Focused RF in High Field 1H-MRSI: Outer Volume Suppression by Local Excitation

Vincent O. Boer¹, Ingmar J. Voogt¹, Hugo Kroeze^1,2, Bart Leo van de Bank¹, A H. Westra², Peter R. Luijten¹, Dennis W.J. Klomp¹

An alternative to SAR demanding outer volume suppression is proposed for 7T MRSI. Low power suppression is achieved by using focused RF to locally saturate subcutaneous signals by using an RF headband; a close fitting, small element, eight-channel transmit receive array. Two sets of RF shims are defined to drive the RF headband; a ring mode for outer volume suppression close to the elements and a quadrature mode for water suppression and excitation of the brain. High spatial resolution MRSI is shown within a short scan time.