Towards functional spin-echo BOLD line-scanning in humans at 7T

MAGMA. 2023 Apr;36(2):317-327. doi: 10.1007/s10334-022-01059-7. Epub 2023 Jan 10.

Abstract

Objective: Neurons cluster into sub-millimeter spatial structures and neural activity occurs at millisecond resolutions; hence, ultimately, high spatial and high temporal resolutions are required for functional MRI. In this work, we implemented a spin-echo line-scanning (SELINE) sequence to use in high spatial and temporal resolution fMRI.

Materials and methods: A line is formed by simply rotating the spin-echo refocusing gradient to a plane perpendicular to the excited slice and by removing the phase-encoding gradient. This technique promises a combination of high spatial and temporal resolution (250 μm, 500 ms) and microvascular specificity of functional responses. We compared SELINE data to a corresponding gradient-echo version (GELINE).

Results: We demonstrate that SELINE showed much-improved line selection (i.e. a sharper line profile) compared to GELINE, albeit at the cost of a significant drop in functional sensitivity.

Discussion: This low functional sensitivity needs to be addressed before SELINE can be applied for neuroscientific purposes.

Keywords: 7T; High spatiotemporal resolution; Line-scanning; Spin-echo; fMRI.

MeSH terms

  • Brain / blood supply
  • Brain Mapping* / methods
  • Echo-Planar Imaging / methods
  • Humans
  • Image Processing, Computer-Assisted / methods
  • Magnetic Resonance Imaging* / methods