Whole-head rapid fMRI acquisition using echo-shifted magnetic resonance inverse imaging

Tutkimustuotos: Lehtiartikkelivertaisarvioitu

Tutkijat

  • Wei-Tang Chang
  • Aapo Nummenmaa
  • Thomas Witzel
  • Jyrki Ahveninen
  • Samantha Huang
  • Kevin Wen Kai Tsai
  • Ying-Hua Chu
  • Jonathan R. Polimeni
  • John W. Belliveau
  • Fa-Hsuan Lin

Organisaatiot

  • Harvard University
  • National Taiwan University

Kuvaus

The acquisition time of BOLD contrast functional MRI (fMRI) data with whole-brain coverage typically requires a sampling rate of one volume in 1-3. s. Although the volumetric sampling time of a few seconds is adequate for measuring the sluggish hemodynamic response (HDR) to neuronal activation, faster sampling of fMRI might allow for monitoring of rapid physiological fluctuations and detection of subtle neuronal activation timing information embedded in BOLD signals. Previous studies utilizing a highly accelerated volumetric MR inverse imaging (InI) technique have provided a sampling rate of one volume per 100. ms with 5. mm spatial resolution. Here, we propose a novel modification of this technique, the echo-shifted InI, which allows TE to be longer than TR, to measure BOLD fMRI at an even faster sampling rate of one volume per 25. ms with whole-brain coverage. Compared with conventional EPI, echo-shifted InI provided an 80-fold speedup with similar spatial resolution and less than 2-fold temporal SNR loss. The capability of echo-shifted InI to detect HDR timing differences was tested empirically. At the group level (n=. 6), echo-spaced InI was able to detect statistically significant HDR timing differences of as low as 50. ms in visual stimulus presentation. At the level of individual subjects, significant differences in HDR timing were detected for 400. ms stimulus-onset differences. Our results also show that the temporal resolution of 25. ms is necessary for maintaining the temporal detecting capability at this level. With the capabilities of being able to distinguish the timing differences in the millisecond scale, echo-shifted InI could be a useful fMRI tool for obtaining temporal information at a time scale closer to that of neuronal dynamics.

Yksityiskohdat

AlkuperäiskieliEnglanti
Sivut325-338
Sivumäärä14
JulkaisuNeuroImage
Vuosikerta78
TilaJulkaistu - syyskuuta 2013
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

ID: 13535371