Magnetization transfer imaging using non-balanced SSFP at ultra-low field

Sharada Balaji; Neale Wiley; Adam Dvorak; Francesco Padormo; Rui P.A.G. Teixiera; Megan E. Poorman; Alex MacKay; Tobias Wood; Adam R. Cassidy; Anthony Traboulsee; David K.B. Li; Irene Vavasour; Steven C.R. Williams; Sean C.L. Deoni; Emil Ljungberg; Shannon H. Kolind

doi:10.1002/mrm.30494

Magnetization transfer imaging using non-balanced SSFP at ultra-low field

Sharada Balaji^*, Neale Wiley, Adam Dvorak, Francesco Padormo, Rui P.A.G. Teixiera, Megan E. Poorman, Alex MacKay, Tobias Wood, Adam R. Cassidy, Anthony Traboulsee, David K.B. Li, Irene Vavasour, Steven C.R. Williams, Sean C.L. Deoni, Emil Ljungberg, Shannon H. Kolind

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

PURPOSE: Ultra-low field MRI scanners have the potential to improve health care delivery, both through improved access in areas where there are few MRI scanners and allowing more frequent monitoring of disease progression and treatment response. This may be particularly true in white matter disorders, including leukodystrophies and multiple sclerosis, in which frequent myelin-sensitive imaging, such as magnetization transfer (MT) imaging, might improve clinical care and patient outcomes.

METHODS: We implemented an on-resonance approach to MT imaging on a commercial point-of-care 64 mT scanner using a non-balanced steady-state free precession sequence. Phantom and in vivo experiments were used to evaluate and optimize the sequence sensitivity and reproducibility, and to demonstrate in vivo performance and inter-site reproducibility.

RESULTS: From phantom experiments, T 1 and T 2 effects were determined to have a negligible effect on the differential MT weighting. MT ratio (MTR) values in white matter were 23.1 ± 1.0% from 10 healthy volunteers, with an average reproducibility coefficient of variation of 1.04%. Normal-appearing white matter MTR values in a multiple sclerosis participant (21.5 ± 6.2%) were lower, but with a similar spread of values, compared to an age-matched healthy volunteer (23.3 ± 6.2%).

CONCLUSION: An on-resonance MT imaging approach was developed at 64 mT that can be performed in as little as 4 min. A semi-quantitative myelin-sensitive imaging biomarker at this field strength is available for assessing both myelination and demyelination.

Original language	English
Pages (from-to)	602-614
Number of pages	13
Journal	Magnetic Resonance in Medicine
Volume	94
Issue number	2
Early online date	17 Mar 2025
DOIs	https://doi.org/10.1002/mrm.30494 https://doi.org/10.1002/mrm.30494
Publication status	E-pub ahead of print - 17 Mar 2025

Keywords

magnetization transfer ratio
multiple sclerosis
myelin imaging
portable point-of-care MRI
ultralow-field MRI

Access to Document

Cite this

Balaji, S., Wiley, N., Dvorak, A., Padormo, F., Teixiera, R. P. A. G., Poorman, M. E., MacKay, A., Wood, T., Cassidy, A. R., Traboulsee, A., Li, D. K. B., Vavasour, I., Williams, S. C. R., Deoni, S. C. L., Ljungberg, E., & Kolind, S. H. (2025). Magnetization transfer imaging using non-balanced SSFP at ultra-low field. Magnetic Resonance in Medicine, 94(2), 602-614. Advance online publication. https://doi.org/10.1002/mrm.30494, https://doi.org/10.1002/mrm.30494

@article{2b5f4fdbafb346808ed32d56db3a549c,

title = "Magnetization transfer imaging using non-balanced SSFP at ultra-low field",

abstract = "PURPOSE: Ultra-low field MRI scanners have the potential to improve health care delivery, both through improved access in areas where there are few MRI scanners and allowing more frequent monitoring of disease progression and treatment response. This may be particularly true in white matter disorders, including leukodystrophies and multiple sclerosis, in which frequent myelin-sensitive imaging, such as magnetization transfer (MT) imaging, might improve clinical care and patient outcomes.METHODS: We implemented an on-resonance approach to MT imaging on a commercial point-of-care 64 mT scanner using a non-balanced steady-state free precession sequence. Phantom and in vivo experiments were used to evaluate and optimize the sequence sensitivity and reproducibility, and to demonstrate in vivo performance and inter-site reproducibility.RESULTS: From phantom experiments, T 1 and T 2 effects were determined to have a negligible effect on the differential MT weighting. MT ratio (MTR) values in white matter were 23.1 ± 1.0% from 10 healthy volunteers, with an average reproducibility coefficient of variation of 1.04%. Normal-appearing white matter MTR values in a multiple sclerosis participant (21.5 ± 6.2%) were lower, but with a similar spread of values, compared to an age-matched healthy volunteer (23.3 ± 6.2%). CONCLUSION: An on-resonance MT imaging approach was developed at 64 mT that can be performed in as little as 4 min. A semi-quantitative myelin-sensitive imaging biomarker at this field strength is available for assessing both myelination and demyelination.",

keywords = "magnetization transfer ratio, multiple sclerosis, myelin imaging, portable point-of-care MRI, ultralow-field MRI",

author = "Sharada Balaji and Neale Wiley and Adam Dvorak and Francesco Padormo and Teixiera, {Rui P.A.G.} and Poorman, {Megan E.} and Alex MacKay and Tobias Wood and Cassidy, {Adam R.} and Anthony Traboulsee and Li, {David K.B.} and Irene Vavasour and Williams, {Steven C.R.} and Deoni, {Sean C.L.} and Emil Ljungberg and Kolind, {Shannon H.}",

note = "Publisher Copyright: {\textcopyright} 2025 The Author(s). Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.",

year = "2025",

month = mar,

day = "17",

doi = "10.1002/mrm.30494",

language = "English",

volume = "94",

pages = "602--614",

journal = "Magnetic Resonance in Medicine",

issn = "0740-3194",

publisher = "WILEY-BLACKWELL",

number = "2",

}

Balaji, S, Wiley, N, Dvorak, A, Padormo, F, Teixiera, RPAG, Poorman, ME, MacKay, A, Wood, T, Cassidy, AR, Traboulsee, A, Li, DKB, Vavasour, I, Williams, SCR , Deoni, SCL , Ljungberg, E & Kolind, SH 2025, 'Magnetization transfer imaging using non-balanced SSFP at ultra-low field', Magnetic Resonance in Medicine, vol. 94, no. 2, pp. 602-614. https://doi.org/10.1002/mrm.30494, https://doi.org/10.1002/mrm.30494

TY - JOUR

T1 - Magnetization transfer imaging using non-balanced SSFP at ultra-low field

AU - Balaji, Sharada

AU - Wiley, Neale

AU - Dvorak, Adam

AU - Padormo, Francesco

AU - Teixiera, Rui P.A.G.

AU - Poorman, Megan E.

AU - MacKay, Alex

AU - Wood, Tobias

AU - Cassidy, Adam R.

AU - Traboulsee, Anthony

AU - Li, David K.B.

AU - Vavasour, Irene

AU - Williams, Steven C.R.

AU - Deoni, Sean C.L.

AU - Ljungberg, Emil

AU - Kolind, Shannon H.

PY - 2025/3/17

Y1 - 2025/3/17

N2 - PURPOSE: Ultra-low field MRI scanners have the potential to improve health care delivery, both through improved access in areas where there are few MRI scanners and allowing more frequent monitoring of disease progression and treatment response. This may be particularly true in white matter disorders, including leukodystrophies and multiple sclerosis, in which frequent myelin-sensitive imaging, such as magnetization transfer (MT) imaging, might improve clinical care and patient outcomes.METHODS: We implemented an on-resonance approach to MT imaging on a commercial point-of-care 64 mT scanner using a non-balanced steady-state free precession sequence. Phantom and in vivo experiments were used to evaluate and optimize the sequence sensitivity and reproducibility, and to demonstrate in vivo performance and inter-site reproducibility.RESULTS: From phantom experiments, T 1 and T 2 effects were determined to have a negligible effect on the differential MT weighting. MT ratio (MTR) values in white matter were 23.1 ± 1.0% from 10 healthy volunteers, with an average reproducibility coefficient of variation of 1.04%. Normal-appearing white matter MTR values in a multiple sclerosis participant (21.5 ± 6.2%) were lower, but with a similar spread of values, compared to an age-matched healthy volunteer (23.3 ± 6.2%). CONCLUSION: An on-resonance MT imaging approach was developed at 64 mT that can be performed in as little as 4 min. A semi-quantitative myelin-sensitive imaging biomarker at this field strength is available for assessing both myelination and demyelination.

AB - PURPOSE: Ultra-low field MRI scanners have the potential to improve health care delivery, both through improved access in areas where there are few MRI scanners and allowing more frequent monitoring of disease progression and treatment response. This may be particularly true in white matter disorders, including leukodystrophies and multiple sclerosis, in which frequent myelin-sensitive imaging, such as magnetization transfer (MT) imaging, might improve clinical care and patient outcomes.METHODS: We implemented an on-resonance approach to MT imaging on a commercial point-of-care 64 mT scanner using a non-balanced steady-state free precession sequence. Phantom and in vivo experiments were used to evaluate and optimize the sequence sensitivity and reproducibility, and to demonstrate in vivo performance and inter-site reproducibility.RESULTS: From phantom experiments, T 1 and T 2 effects were determined to have a negligible effect on the differential MT weighting. MT ratio (MTR) values in white matter were 23.1 ± 1.0% from 10 healthy volunteers, with an average reproducibility coefficient of variation of 1.04%. Normal-appearing white matter MTR values in a multiple sclerosis participant (21.5 ± 6.2%) were lower, but with a similar spread of values, compared to an age-matched healthy volunteer (23.3 ± 6.2%). CONCLUSION: An on-resonance MT imaging approach was developed at 64 mT that can be performed in as little as 4 min. A semi-quantitative myelin-sensitive imaging biomarker at this field strength is available for assessing both myelination and demyelination.

KW - magnetization transfer ratio

KW - multiple sclerosis

KW - myelin imaging

KW - portable point-of-care MRI

KW - ultralow-field MRI

UR - http://www.scopus.com/inward/record.url?scp=105000234538&partnerID=8YFLogxK

U2 - 10.1002/mrm.30494

DO - 10.1002/mrm.30494

M3 - Article

C2 - 40096549

AN - SCOPUS:105000234538

SN - 0740-3194

VL - 94

SP - 602

EP - 614

JO - Magnetic Resonance in Medicine

JF - Magnetic Resonance in Medicine

IS - 2

ER -

Magnetization transfer imaging using non-balanced SSFP at ultra-low field

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this