Improved sensitivity and specificity for resting state and task fMRI with multiband multi-echo EPI compared to multi-echo EPI at 7 T

Accelerated Resting-State Functional Magnetic Resonance Imaging Using Multiband Echo-Planar Imaging with Controlled Aliasing

“…In all three data sets, tSNR was higher in white matter than in gray matter, which is consistent with the findings of previous reports (11). Our ANOVA analysis revealed that tSNR was higher in conventional EPI than in multiband accelerated EPI, mostly in white matter structures.…”

“…Therefore, maximal sensitivity and high tSNR is required for reliable detection. Although several studies have examined the performance of a combined approach in which rs-fMRI data are acquired with a multiband and multi-echo acquisition (10,11), the performance of multiband and single-echo EPI acquisition over conventional single-echo EPI acquisition in rs-fMRI has not been explored.…”

How to choose the right MR sequence for your research question at 7 T and above?

“…At higher spatial resolutions the EPI readout train will become too long for multi-echo, and in plane acceleration (probably combined with partial Fourier acquisition) will be necessary to control blurring and image distortion and ensure the optimum echo time can be attained. Hence, from pure efficiency considerations alone, the best pulse sequence for spatial resolutions at, or coarser than, the spatial FWHM width of the BOLD response, would be a multi-echo gradient-echo EPI, with sufficient in-plane acceleration to ensure an acceptable level of blurring, and the remainder of the acceleration utilised by using SMS as this has been shown superior to multi-echo without slice-acceleration (Boyacioglu et al, 2015). Once the readout train duration becomes too long to be compatible with multi-echo acquisition then single echo should be used.…”

Denoising spinal cord fMRI data: Approaches to acquisition and analysis

“…These multi-echo functional imaging techniques (Kundu et al, 2012) have shown great promise for improving the quality of fMRI data acquired from the brain, but have yet to be exploited for imaging the spinal cord. One might also use simultaneous multi-slice (or "multi-band") EPI, which allows a shortening of the TR due to the simultaneous excitation of several slices (Barth et al, 2016; interestingly, this approach has recently been combined with a multi-echo technique: Boyacioğlu et al, 2015); this approach requires a certain coil geometry, but would potentially allow one to critically sample cardiac and respiratory artefacts and thus remove them based on frequency spectra (which is not possible with standard TRs due to the aliasing that occurs). An alternative approach to improving the specificity of spinal cord fMRI is to reduce voxel sizes, which has been shown to reduce the influence of physiological noise (Hutton et al, 2011).…”