An in-vivo study of BOLD laminar responses as a function of echo time and static magnetic field strength

Irati Markuerkiaga, José P. Marques, Lauren J. Bains, David G. Norris*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Scopus)
7 Downloads (Pure)

Abstract

Layer specific functional MRI requires high spatial resolution data. To compensate the associated poor signal to noise ratio it is common to integrate the signal from voxels at a given cortical depth. If the region is sufficiently large then physiological noise will be the dominant noise source. In this work, activation profiles in response to the same visual stimulus are compared at 1.5 T, 3 T and 7 T using a multi-echo, gradient echo (GE) FLASH sequence, with a 0.75 mm isotropic voxel size and the cortical integration approach. The results show that after integrating over a cortical volume of 40, 60 and 100 mm3 (at 7 T, 3 T, and 1.5 T, respectively), the signal is in the physiological noise dominated regime. The activation profiles obtained are similar for equivalent echo times. BOLD-like noise is found to be the dominant source of physiological noise. Consequently, the functional contrast to noise ratio is not strongly echo-time or field-strength dependent. We conclude that laminar GE-BOLD fMRI at lower field strengths is feasible but that larger patches of cortex will need to be examined, and that the acquisition efficiency is reduced.

Original languageEnglish
Article number1862
JournalScientific reports
Volume11
Issue number1
DOIs
Publication statusPublished - 21 Jan 2021
Externally publishedYes

Fingerprint

Dive into the research topics of 'An in-vivo study of BOLD laminar responses as a function of echo time and static magnetic field strength'. Together they form a unique fingerprint.

Cite this