Donders Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, HB Nijmegen NL-6500, The Netherlands.
Magn Reson Med. 2013 Jun;69(6):1670-6. doi: 10.1002/mrm.24402. Epub 2012 Jul 17.
A method for simultaneous multislice (SMS) inversion contrast imaging is presented using a combination of the delays alternating with nutation for tailored excitation (DANTE) and the power independent of the number of slices (PINS) techniques. In SMS imaging, simultaneously excited slices result in an aliased image that is disentangled using parallel imaging reconstruction techniques. At high-magnetic field strengths, the peak amplitude and specific absorption rate of conventional (summed) SMS radio frequency pulses can be prohibitively high. Using the PINS approach, specific absorption rate is independent of the number of slices allowing high SMS acceleration factors even at high fields. Using DANTE, adiabatic SMS radio frequency pulses can be created to be combined with PINS. This allows 2D imaging protocols that employ adiabatic pulses to also reap the benefits of low specific absorption rate SMS acceleration. As a proof-of-concept, simulations and measurements using hyperbolic secant inversion pulses are shown.
提出了一种使用延迟交替反转全激发(DANTE)和独立于切片数的功率(PINS)技术相结合的同时多层(SMS)反转对比成像方法。在 SMS 成像中,同时激发的切片会产生混叠图像,通过并行成像重建技术将其分离。在高磁场强度下,传统(求和)SMS 射频脉冲的峰值幅度和比吸收率可能非常高。使用 PINS 方法,比吸收率与切片数无关,允许在高场下实现高 SMS 加速因子。使用 DANTE,可以创建绝热 SMS 射频脉冲,与 PINS 结合使用。这允许使用绝热脉冲的 2D 成像协议也能受益于低比吸收率 SMS 加速。作为概念验证,展示了使用双曲正割反转脉冲的仿真和测量结果。