Abstract
Resting state functional magnetic resonance imaging (fMRI) has been used to study human brain function for over two decades, but only recently has this technique been successfully translated to the human spinal cord. The spinal cord is structurally and functionally unique, so resting state fMRI methods developed and optimized for the brain may not be appropriate when applied to the cord. This report therefore investigates the relative impact of different acquisition and processing choices (including run length, echo time, and bandpass filter width) on the detectability of resting state spinal cord networks at 3T. Our results suggest that frequencies beyond 0.08 Hz should be included in resting state analyses, a run length of ~8–12 mins is appropriate for reliable detection of the ventral (motor) network, and longer echo times – yet still shorter than values typically used for fMRI in the brain – may increase the detectability of the dorsal (sensory) network. Further studies are required to more fully understand and interpret the nature of resting state spinal cord networks in health and in disease, and the protocols described in this report are designed to assist such studies.
Highlights
For over two decades, functional magnetic resonance imaging studies of resting state connectivity in the brain have provided unparalleled insight into the functional architecture of the central nervous system in health[1,2] and disease[3]
This paper explores the impact of three factors – run length, bandpass filter width, and TE – on the detectability of resting state spinal cord networks
The conventional wisdom in brain functional magnetic resonance imaging (fMRI) is to set TE to be equal to T2* to maximize blood oxygenation level dependent (BOLD) contrast-to-noise ratio (CNR)
Summary
Functional magnetic resonance imaging (fMRI) studies of resting state connectivity in the brain have provided unparalleled insight into the functional architecture of the central nervous system in health[1,2] and disease[3]. While most resting state studies consider only a low-frequency bandwidth between 0.01 and ~0.1 Hz, a growing number of reports suggest that the inclusion of higher frequencies, for example, up to 0.5 Hz31, 0.75 Hz32, and potentially even 3.7 Hz33, may increase the detectability of functional networks. One study evaluated two 20-min acquisitions with three bandpass filter ranges, and a second investigated the effects of increasing TE on functional image quality and network detectability. While these studies use 3D gradient echo acquisition sequences to mitigate distortions, future optimization studies may consider the use of more traditional 2D echo planar imaging (EPI) sequences
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
