Whole brain, high resolution spin-echo resting state fMRI using PINS multiplexing at 7T

Koopmans, Peter J.; Boyacıoğlu, Rasim; Barth, Markus; Norris, David G.

doi:10.1016/j.neuroimage.2012.05.080

Cited by 57 publications

(53 citation statements)

References 37 publications

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“…Additional components were identified after visual inspection. Names for each RSN were assigned by means of visual comparison to published data (22,(51)(52)(53)(54) …”

Section: Physiological Noise Characterizationmentioning

confidence: 99%

Three‐dimensional echo planar imaging with controlled aliasing: A sequence for high temporal resolution functional MRI

Narsude

Gallichan

Zwaag

et al. 2015

Magnetic Resonance in Med

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Purpose: In this work, we combine three-dimensional echo planar imaging (3D-EPI) with controlled aliasing to substantially increase temporal resolution in whole-brain functional MRI (fMRI) while minimizing geometry-factor (g-factor) losses. Theory and Methods: The study was performed on a 7 Tesla scanner equipped with a 32-channel receive coil. The proposed 3D-EPI-CAIPI sequence was evaluated for: (i) image quality, compared with a conventionally undersampled parallel imaging acquisition; (ii) temporal resolution, the ability to sample and remove physiological signal fluctuations from the fMRI signal of interest and (iii) the ability to distinguish small changes in hemodynamic responses in an event-related fMRI experiment. Results: Whole-brain fMRI data with a voxel size of 2 Â 2 Â 2 mm 3 and temporal resolution of 371 ms could be acquired with acceptable image quality. Ten-fold parallel imaging accelerated 3D-EPI-CAIPI data were shown to lower the maximum g-factor losses up to 62% with respect to a 10-fold accelerated 3D-EPI dataset. FMRI with 400 ms temporal resolution allowed the detection of time-to-peak variations in functional responses due to multisensory facilitation in temporal, occipital and frontal cortices. Conclusion: 3D-EPI-CAIPI allows increased temporal resolution that enables better characterization of physiological noise, thus improving sensitivity to signal changes of interest. Furthermore, subtle changes in hemodynamic response dynamics can be studied in shorter scan times by avoiding the need for jittering.

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“…Additional components were identified after visual inspection. Names for each RSN were assigned by means of visual comparison to published data (22,(51)(52)(53)(54) …”

Section: Physiological Noise Characterizationmentioning

confidence: 99%

Three‐dimensional echo planar imaging with controlled aliasing: A sequence for high temporal resolution functional MRI

Narsude

Gallichan

Zwaag

et al. 2015

Magnetic Resonance in Med

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“…In a previous study (Koopmans et al, 2012) PINS pulses were employed in a SE EPI sequence both for excitation and refocusing. This excludes slice orientations having a gradient component along the z-axis (i.e.…”

Section: Acquisitionmentioning

confidence: 99%

“…Evidently, this poses problems for SE EPI at high field due to the high specific absorption rate (SAR) of the refocusing pulses. Recently, to overcome this SAR limitation problem, Power Independent Number of Slices (PINS) pulses (Norris et al, 2011) were introduced and have been used in a high resolution SE EPI resting state (RS) study at 7T (Koopmans et al, 2012) and for high spatial resolution DWI also at 7T (Eichner et al, 2013). Due to the periodic excitation profile of the PINS pulses, a sagittal acquisition scheme was adopted for the SE EPI RS study.…”

Section: Introductionmentioning

confidence: 99%

Whole brain, high resolution multiband spin-echo EPI fMRI at 7T: A comparison with gradient-echo EPI using a color-word Stroop task

et al. 2014

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A whole brain, multiband spin-echo (SE) echo planar imaging (EPI) sequence employing a high spatial (1.5 mm isotropic) and temporal (TR of 2 s) resolution was implemented at 7 Tesla. Its overall performance (tSNR, sensitivity and CNR) was assessed and compared to a geometrically matched gradient-echo (GE) EPI multiband sequence (TR of 1.4 s) using a colour-word Stroop task. PINS RF pulses were used for refocusing to reduce RF amplitude requirements and SAR, summed and phaseoptimized standard pulses were used for excitation enabling a transverse or oblique slice orientation. The distortions were minimized with the use of parallel imaging in the phase encoding direction and a post-acquisition distortion correction. In general, GE-EPI shows higher efficiency and higher CNR in most brain areas except in some parts of the visual cortex and superior frontal pole at both the group and individual-subject levels. Gradient-echo EPI was able to detect robust activation near the air/tissue interfaces such as the orbito-frontal and subcortical regions due to reduced intra-voxel dephasing because of the thin slices used and high in-plane resolution.

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“…The simultaneous acquisition of multiple slices can greatly reduce total imaging acquisition time for whole brain applications with EPI, and particularly has the potential to improve whole brain ASL perfusion studies where high in-plane and through-plane resolution is desired, necessitating the use of a large number of thin imaging slices to achieve the desired coverage. MB-EPI has been successfully demonstrated in functional magnetic resonance imaging (fMRI) (Moeller et al, 2010) and resting state fMRI (Feinberg et al, 2010, Koopmans et al, 2012, Smith et al, 2012), showing improved detection of resting sate networks, as well as diffusion-weighted imaging (DWI) (Feinberg et al, 2010, Setsompop et al, 2012a) for dramatic reductions in imaging time. As such, MB-EPI has become an essential data acquisition strategy for both fMRI and DWI in the Human Connectome Project (Van Essen et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Theoretical and experimental evaluation of multi-band EPI for high-resolution whole brain pCASL Imaging

Wang

Auerbach

et al. 2015

NeuroImage

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Multi-Band Echo Planar Imaging (MB-EPI), a new approach to increase data acquisition efficiency and/or temporal resolution, has the potential to overcome critical limitations of standard acquisition strategies for obtaining high-resolution whole brain perfusion imaging using arterial spin labeling (ASL). However, the use of MB also introduces confounding effects, such as spatially varying amplified thermal noise and leakage contamination, which have not been evaluated to date as to their effect on cerebral blood flow (CBF) estimation. In this study, both the potential benefits and confounding effects of MB-EPI were systematically evaluated through both simulation and experimentally using a pseudo-continuous arterial spin labeling (pCASL) strategy. These studies revealed that the amplified noise, given by the geometry factor (g-factor), and the leakage contamination, assessed by the total leakage factor (TLF), have minimal impact on CBF estimation. Furthermore, it is demonstrated that MB-EPI greatly benefits high-resolution whole brain pCASL studies in terms of improved spatial and temporal signal-to-noise ratio efficiency, and increases compliance with the assumptions of the commonly used single blood compartment model, resulting in improved CBF estimates.

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Whole brain, high resolution spin-echo resting state fMRI using PINS multiplexing at 7T

Cited by 57 publications

References 37 publications

Three‐dimensional echo planar imaging with controlled aliasing: A sequence for high temporal resolution functional MRI

Three‐dimensional echo planar imaging with controlled aliasing: A sequence for high temporal resolution functional MRI

Whole brain, high resolution multiband spin-echo EPI fMRI at 7T: A comparison with gradient-echo EPI using a color-word Stroop task

Theoretical and experimental evaluation of multi-band EPI for high-resolution whole brain pCASL Imaging

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