A 16-channel AC/DC array coil for anesthetized monkey whole-brain imaging at 7T

Yang Gao, Azma Mareyam, Yi Sun, Thomas Witzel, Nicolas Arango, Irene Kuang, Jacob White, Anna Wang Roe, Lawrence Wald, Jason Stockmann, Xiaotong Zhang

Research output: Contribution to journalArticle

Abstract

Functional magnetic resonance imaging (fMRI) in monkeys is important for bridging the gap between invasive animal brain studies and non-invasive human brain studies. To resolve the finer functional structure of the monkey brain, ultra-high-field (UHF) MR is essential, and high-performance, close-fitting RF receive coils are typically desired to fully leverage the intrinsic gains provided by UHF MRI. Moreover, static field (B0) inhomogeneity arising from the tissue susceptibility interface is more severe at UHF, presenting an obstacle to achieving high-resolution fMRI. B0 shim of the monkey head is challenging due to its smaller size and more complex sources of B0 offsets in multi-modal imaging tasks. In the present work, we have customized an array coil for lightly-anesthetized monkey fMRI in the 7T human scanner that combines RF and multi-coil (MC) B0 shim functionality (also referred to as AC/DC coils) to provide high imaging SNR and high-spatial-order, rapidly switchable B0-shim capability. Additional space was retained on the coil to render it compatible with monkey multi-modal imaging studies. Both MC global (whole-volume) and dynamic (slice-optimized) shim methods were tested and evaluated, and the benefits of MC shim for fMRI experiments was also studied. A minor reduction in RF coil performance was found after introducing additional B0 shim circuitry. However, the proposed RF coil provided higher image SNR and more uniform contrast compared to a commercially available coil for human knee imaging. Compared with static 2nd-order shim, the B0 inhomogeneity was reduced by 56.8%, and 95-percentile B0 offset was reduced to within 28.2 Hz through MC shim, versus 68.7 Hz with 2nd-order static shim. As a result, functional image quality could be improved, and brain activation can be better detected using the proposed AC/DC monkey coil.

Original languageEnglish (US)
Article number116396
JournalNeuroImage
DOIs
StateAccepted/In press - Jan 1 2019

Fingerprint

Neuroimaging
Haplorhini
Magnetic Resonance Imaging
Brain
Knee
Head

Keywords

  • Anesthetized monkey
  • B0 shim
  • Magnetic resonance imaging (MRI)
  • Multi-coil shim
  • Multi-modal neuroimaging
  • RF coil

ASJC Scopus subject areas

  • Neurology
  • Cognitive Neuroscience

Cite this

Gao, Y., Mareyam, A., Sun, Y., Witzel, T., Arango, N., Kuang, I., ... Zhang, X. (Accepted/In press). A 16-channel AC/DC array coil for anesthetized monkey whole-brain imaging at 7T. NeuroImage, [116396]. https://doi.org/10.1016/j.neuroimage.2019.116396

A 16-channel AC/DC array coil for anesthetized monkey whole-brain imaging at 7T. / Gao, Yang; Mareyam, Azma; Sun, Yi; Witzel, Thomas; Arango, Nicolas; Kuang, Irene; White, Jacob; Roe, Anna Wang; Wald, Lawrence; Stockmann, Jason; Zhang, Xiaotong.

In: NeuroImage, 01.01.2019.

Research output: Contribution to journalArticle

Gao, Y, Mareyam, A, Sun, Y, Witzel, T, Arango, N, Kuang, I, White, J, Roe, AW, Wald, L, Stockmann, J & Zhang, X 2019, 'A 16-channel AC/DC array coil for anesthetized monkey whole-brain imaging at 7T', NeuroImage. https://doi.org/10.1016/j.neuroimage.2019.116396
Gao, Yang ; Mareyam, Azma ; Sun, Yi ; Witzel, Thomas ; Arango, Nicolas ; Kuang, Irene ; White, Jacob ; Roe, Anna Wang ; Wald, Lawrence ; Stockmann, Jason ; Zhang, Xiaotong. / A 16-channel AC/DC array coil for anesthetized monkey whole-brain imaging at 7T. In: NeuroImage. 2019.
@article{a0a942b6d6f0437d916c51860cedc3c1,
title = "A 16-channel AC/DC array coil for anesthetized monkey whole-brain imaging at 7T",
abstract = "Functional magnetic resonance imaging (fMRI) in monkeys is important for bridging the gap between invasive animal brain studies and non-invasive human brain studies. To resolve the finer functional structure of the monkey brain, ultra-high-field (UHF) MR is essential, and high-performance, close-fitting RF receive coils are typically desired to fully leverage the intrinsic gains provided by UHF MRI. Moreover, static field (B0) inhomogeneity arising from the tissue susceptibility interface is more severe at UHF, presenting an obstacle to achieving high-resolution fMRI. B0 shim of the monkey head is challenging due to its smaller size and more complex sources of B0 offsets in multi-modal imaging tasks. In the present work, we have customized an array coil for lightly-anesthetized monkey fMRI in the 7T human scanner that combines RF and multi-coil (MC) B0 shim functionality (also referred to as AC/DC coils) to provide high imaging SNR and high-spatial-order, rapidly switchable B0-shim capability. Additional space was retained on the coil to render it compatible with monkey multi-modal imaging studies. Both MC global (whole-volume) and dynamic (slice-optimized) shim methods were tested and evaluated, and the benefits of MC shim for fMRI experiments was also studied. A minor reduction in RF coil performance was found after introducing additional B0 shim circuitry. However, the proposed RF coil provided higher image SNR and more uniform contrast compared to a commercially available coil for human knee imaging. Compared with static 2nd-order shim, the B0 inhomogeneity was reduced by 56.8{\%}, and 95-percentile B0 offset was reduced to within 28.2 Hz through MC shim, versus 68.7 Hz with 2nd-order static shim. As a result, functional image quality could be improved, and brain activation can be better detected using the proposed AC/DC monkey coil.",
keywords = "Anesthetized monkey, B0 shim, Magnetic resonance imaging (MRI), Multi-coil shim, Multi-modal neuroimaging, RF coil",
author = "Yang Gao and Azma Mareyam and Yi Sun and Thomas Witzel and Nicolas Arango and Irene Kuang and Jacob White and Roe, {Anna Wang} and Lawrence Wald and Jason Stockmann and Xiaotong Zhang",
year = "2019",
month = "1",
day = "1",
doi = "10.1016/j.neuroimage.2019.116396",
language = "English (US)",
journal = "NeuroImage",
issn = "1053-8119",
publisher = "Academic Press Inc.",

}

TY - JOUR

T1 - A 16-channel AC/DC array coil for anesthetized monkey whole-brain imaging at 7T

AU - Gao, Yang

AU - Mareyam, Azma

AU - Sun, Yi

AU - Witzel, Thomas

AU - Arango, Nicolas

AU - Kuang, Irene

AU - White, Jacob

AU - Roe, Anna Wang

AU - Wald, Lawrence

AU - Stockmann, Jason

AU - Zhang, Xiaotong

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Functional magnetic resonance imaging (fMRI) in monkeys is important for bridging the gap between invasive animal brain studies and non-invasive human brain studies. To resolve the finer functional structure of the monkey brain, ultra-high-field (UHF) MR is essential, and high-performance, close-fitting RF receive coils are typically desired to fully leverage the intrinsic gains provided by UHF MRI. Moreover, static field (B0) inhomogeneity arising from the tissue susceptibility interface is more severe at UHF, presenting an obstacle to achieving high-resolution fMRI. B0 shim of the monkey head is challenging due to its smaller size and more complex sources of B0 offsets in multi-modal imaging tasks. In the present work, we have customized an array coil for lightly-anesthetized monkey fMRI in the 7T human scanner that combines RF and multi-coil (MC) B0 shim functionality (also referred to as AC/DC coils) to provide high imaging SNR and high-spatial-order, rapidly switchable B0-shim capability. Additional space was retained on the coil to render it compatible with monkey multi-modal imaging studies. Both MC global (whole-volume) and dynamic (slice-optimized) shim methods were tested and evaluated, and the benefits of MC shim for fMRI experiments was also studied. A minor reduction in RF coil performance was found after introducing additional B0 shim circuitry. However, the proposed RF coil provided higher image SNR and more uniform contrast compared to a commercially available coil for human knee imaging. Compared with static 2nd-order shim, the B0 inhomogeneity was reduced by 56.8%, and 95-percentile B0 offset was reduced to within 28.2 Hz through MC shim, versus 68.7 Hz with 2nd-order static shim. As a result, functional image quality could be improved, and brain activation can be better detected using the proposed AC/DC monkey coil.

AB - Functional magnetic resonance imaging (fMRI) in monkeys is important for bridging the gap between invasive animal brain studies and non-invasive human brain studies. To resolve the finer functional structure of the monkey brain, ultra-high-field (UHF) MR is essential, and high-performance, close-fitting RF receive coils are typically desired to fully leverage the intrinsic gains provided by UHF MRI. Moreover, static field (B0) inhomogeneity arising from the tissue susceptibility interface is more severe at UHF, presenting an obstacle to achieving high-resolution fMRI. B0 shim of the monkey head is challenging due to its smaller size and more complex sources of B0 offsets in multi-modal imaging tasks. In the present work, we have customized an array coil for lightly-anesthetized monkey fMRI in the 7T human scanner that combines RF and multi-coil (MC) B0 shim functionality (also referred to as AC/DC coils) to provide high imaging SNR and high-spatial-order, rapidly switchable B0-shim capability. Additional space was retained on the coil to render it compatible with monkey multi-modal imaging studies. Both MC global (whole-volume) and dynamic (slice-optimized) shim methods were tested and evaluated, and the benefits of MC shim for fMRI experiments was also studied. A minor reduction in RF coil performance was found after introducing additional B0 shim circuitry. However, the proposed RF coil provided higher image SNR and more uniform contrast compared to a commercially available coil for human knee imaging. Compared with static 2nd-order shim, the B0 inhomogeneity was reduced by 56.8%, and 95-percentile B0 offset was reduced to within 28.2 Hz through MC shim, versus 68.7 Hz with 2nd-order static shim. As a result, functional image quality could be improved, and brain activation can be better detected using the proposed AC/DC monkey coil.

KW - Anesthetized monkey

KW - B0 shim

KW - Magnetic resonance imaging (MRI)

KW - Multi-coil shim

KW - Multi-modal neuroimaging

KW - RF coil

UR - http://www.scopus.com/inward/record.url?scp=85076230813&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85076230813&partnerID=8YFLogxK

U2 - 10.1016/j.neuroimage.2019.116396

DO - 10.1016/j.neuroimage.2019.116396

M3 - Article

C2 - 31778818

AN - SCOPUS:85076230813

JO - NeuroImage

JF - NeuroImage

SN - 1053-8119

M1 - 116396

ER -