Title
Whole-head rapid fMRI acquisition using echo-shifted magnetic resonance inverse imaging.
Abstract
The acquisition time of BOLD contrast functional MRI (fMRI) data with whole-brain coverage typically requires a sampling rate of one volume in 1–3s. 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 100ms with 5mm 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 25ms 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 50ms in visual stimulus presentation. At the level of individual subjects, significant differences in HDR timing were detected for 400ms stimulus-onset differences. Our results also show that the temporal resolution of 25ms 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.
Year
DOI
Venue
2013
10.1016/j.neuroimage.2013.03.040
NeuroImage
Keywords
Field
DocType
Echo-shifting,Inverse imaging,fMRI,Parallel imaging
Brain mapping,Computer vision,Visual cortex,Computer science,Sampling (signal processing),Millisecond,Sampling (statistics),Artificial intelligence,Image resolution,Temporal resolution,Magnetic resonance imaging
Journal
Volume
ISSN
Citations 
78
1053-8119
11
PageRank 
References 
Authors
0.64
16
10
Name
Order
Citations
PageRank
Wei-Tang Chang1727.68
Aapo Nummenmaa225619.18
Thomas Witzel337428.70
Jyrki Ahveninen48915.15
Samantha Huang5213.16
Kevin Wen-Kai Tsai6494.60
Ying-Hua Chu7332.99
Jonathan R. Polimeni897250.64
John W Belliveau925638.29
Fa-Hsuan Lin1024624.33