• Benedikt A Poser, Robert James Anderson, Bastien Guérin, Kawin Setsompop, Weiran Deng, Azma Mareyam, Peter Serano, Lawrence L Wald, and V Andrew Stenger.
• Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA.
• Magn Reson Med. 2014 Apr 1; 71 (4): 1416-27.

PurposeA technique is described for simultaneous multislice (SMS) excitation using radiofrequency (RF) parallel transmission (pTX).MethodsSpatially distinct slices are simultaneously excited by applying different RF frequencies on groups of elements of a multichannel transmit array. The localized transmit sensitivities of the coil geometry are thereby exploited to reduce RF power. The method is capable of achieving SMS-excitation using single-slice RF pulses, or multiband pulses. SMS-pTX is demonstrated using eight-channel parallel RF transmission on a dual-ring pTX coil at 3 T. The effect on B(1)(+) homogeneity and specific absorption rate (SAR) is evaluated experimentally and by simulations. Slice-GRAPPA reconstruction was used for separation of the collapsed slice signals.ResultsPhantom and in vivo brain data acquired with fast low-angle shot (FLASH) and blipped-controlled aliasing results in higher acceleration (CAIPIRINHA) echo-planar imaging are presented at SMS excitation factors of two, four, and six. We also show that with our pTX coil design, slice placement, and binary division of transmitters, SMS-pTX excitations can achieve the same mean flip angles excitations at ∼30% lower RF power than a conventional SMS approach with multiband RF pulses.ConclusionThe proposed SMS-pTX allows SMS excitations at reduced RF power by exploiting the local B(1)(+) sensitivities of suitable multielement pTX arrays.Copyright © 2013 Wiley Periodicals, Inc.

23 keywords...

hide…