Alpha-180 spin-echo-based line-scanning method for high-resolution laminar-specific fMRI in animals Articles uri icon

authors

  • Choi, Sangcheon
  • Hike, David
  • Pohmann, Rolf
  • Avdievich, Nikolai
  • GOMEZ CID, LIDIA
  • Man, Weitao
  • Scheffler, Klaus
  • Yu, Xin

publication date

  • March 2024

start page

  • 1

end page

  • 14

volume

  • 2

Electronic International Standard Serial Number (EISSN)

  • 2837-6056

abstract

  • Laminar-specific
    functional magnetic resonance imaging (fMRI) has been widely used to study circuit-specific
    neuronal
    activity by mapping spatiotemporal fMRI response patterns across cortical layers. Hemodynamic responses reflect
    indirect neuronal activity given the limitation of spatial and temporal resolution. Previously, a gradient-echo-
    based
    line-scanning
    fMRI (GELINE) method was proposed with high temporal (50 ms) and spatial (50 μm) resolution to better
    characterize the fMRI onset time across cortical layers by employing two saturation RF pulses. However, the imperfect
    RF saturation performance led to poor boundary definition of the reduced region of interest (ROI) and aliasing problems
    outside of the ROI. Here, we propose an α (alpha)-180
    spin-echo-
    based
    line-scanning
    fMRI (SELINE) method in animals
    to resolve this issue by employing a refocusing 180˚ RF pulse perpendicular to the excitation slice (without any
    saturation RF pulse) and also achieve high spatiotemporal resolution. In contrast to GELINE signals which peaked at
    the superficial layer, we detected varied peaks of laminar-specific
    BOLD signals across deeper cortical layers using the
    SELINE method, indicating the well-defined
    exclusion of the large draining-vein
    effect using the spin-echo
    sequence.
    Furthermore, we applied the SELINE method with a 200 ms repetition time (TR) to sample the fast hemodynamic
    changes across cortical layers with a less draining vein effect. In summary, this SELINE method provides a novel acquisition
    scheme to identify microvascular-sensitive
    laminar-specific
    BOLD responses across cortical depth

subjects

  • Biology and Biomedicine

keywords

  • microvascular sensitivity; laminar specificity; line-scanning; high-resolution fmri; spin-echo