Dear FCP/INDI Users,
You may have noticed that we changed the name of the recent release from “Multiplexed Imaging Test-Retest Pilot Data” to “Multiband Imaging Test-Retest Pilot Data”. This was in response to a terminological clarification brought to our attention by Kamil Ugurbil. While the terms ‘Multiplexed’ and ‘Multiband’ are often used somewhat interchangeably, they are not equivalent.
As reviewed thoroughly at: http://www.cmrr.umn.edu/research/neuro-3.shtml, multiplexed imaging combined multiband imaging ([1], [2]) with simultaneousimage refocusing (SIR) techniques ([3]). The Human Connectome project and Enhanced NKI-Rockland samples are both using multiband sequences, with recent innovations included ([4],[5]). The recent paper by Smith et al. (2012) in PNAS [7] is another example of multiband data. A notable example of multiplexed data is that presented by Feinberg et al. (2010) in PLoS One [6].
Per Kamil Ugurbil:
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Multiplexed EPI can achieve further accelerations beyond Multiband. However, especially for high resolution (e.g. 2 mm isotropic or better), combination with SIR starts imposing limitations due to increased echo train length, which leads to increased image distortions or necessitates the use of in-plane parallel imaging with its own consequent problems (e.g. loss in SNR and possibly the need to reduce slice acceleration in the multiband component). But with the latest improvements in the multiband technique (Xu et al., 2012) [5], there is not a need to incorporate SIR at this point to achieve the accelerations required for higherspatial or temporal resolutions.
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We hope this clarification prevents any confusion regarding the terminology, and apologize for our own personal confusion on the issue.
Best,
Mike
References:
[1] Moeller, S., E. Auerbach, P.-F. van de Moortele, G. Adriany and K. Ugurbil (2008). "fMRI with 16 fold reduction using multibanded multislice sampling." Proc. Int. Soc. Magn. Reson. in Med. 16:p. 2366.
[2] Moeller, S., E. Yacoub, C. A. Olman, E. Auerbach, J. Strupp, N. Harel and K. Ugurbil (2010). "Multiband multislice GE-EPI at 7 tesla, with 16-fold acceleration using partial parallel imaging with application to high spatial and temporal whole-brain fMRI." Magn Reson Med 63(5): 1144-1153.
[3] Feinberg, D.A., T.G. Reese, and V.J. Wedeen: Simultaneous echo refocusing in EPI. Magn Reson Med, 2002. 48(1): p. 1-5.
[4] Setsompop, K., B. A. Gagoski, J. R. Polimeni, T. Witzel, V. J. Wedeen and L. L. Wald (2011). "Blipped-controlled aliasing in parallel imaging for simultaneous multislice echo planer imaging with reduced g-factor penalty." Magn Reson Med
[5] Xu, J., S. Moeller, J. Strupp, E. Auerbach, L. Chen, D. Feinberg, K. Ugurbil and E. Yacoub (2012). "Highly accelerated whole Brain Imaging Using Aligned-Blipped-Controlled Aliasing Multiband EPI." Proc. Int. Soc. Mag Reson Med.
[6] Feinberg, D. A., S. Moeller, S. M. Smith, E. Auerbach, S. Ramanna, M. F. Glasser, K. L. Miller, K. Ugurbil and E. Yacoub (2010). "Multiplexed echo planar imaging for sub-second whole brain FMRI and fast diffusion imaging." PLoS ONE 5(12): e15710.
[7] Smith SM, Miller KL, Moeller S, Xu J, Auerbach EJ, Woolrich MW, Beckmann CF, Jenkinson M, Andersson J, Glasser MF, Van Essen DC, Feinberg DA, Yacoub ES, Ugurbil K. (2012). Temporally-independent functional modes of spontaneous brain activity. ProcNatl Acad Sci U S A.