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Design analysis of an MPI human functional brain scanner

MPI’s high sensitivity makes it a promising modality for imaging brain function. Functional contrast is proposed based on blood SPION concentration changes due to Cerebral Blood Volume (CBV) increases during activation, a mechanism utilized in fMRI studies. MPI offers the potential for a direct and...

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Autores principales: Mason, Erica E., Cooley, Clarissa Z., Cauley, Stephen F., Griswold, Mark A., Conolly, Steven M., Wald, Lawrence L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5526464/
https://www.ncbi.nlm.nih.gov/pubmed/28752130
http://dx.doi.org/10.18416/ijmpi.2017.1703008
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author Mason, Erica E.
Cooley, Clarissa Z.
Cauley, Stephen F.
Griswold, Mark A.
Conolly, Steven M.
Wald, Lawrence L.
author_facet Mason, Erica E.
Cooley, Clarissa Z.
Cauley, Stephen F.
Griswold, Mark A.
Conolly, Steven M.
Wald, Lawrence L.
author_sort Mason, Erica E.
collection PubMed
description MPI’s high sensitivity makes it a promising modality for imaging brain function. Functional contrast is proposed based on blood SPION concentration changes due to Cerebral Blood Volume (CBV) increases during activation, a mechanism utilized in fMRI studies. MPI offers the potential for a direct and more sensitive measure of SPION concentration, and thus CBV, than fMRI. As such, fMPI could surpass fMRI in sensitivity, enhancing the scientific and clinical value of functional imaging. As human-sized MPI systems have not been attempted, we assess the technical challenges of scaling MPI from rodent to human brain. We use a full-system MPI simulator to test arbitrary hardware designs and encoding practices, and we examine tradeoffs imposed by constraints that arise when scaling to human size as well as safety constraints (PNS and central nervous system stimulation) not considered in animal scanners, thereby estimating spatial resolutions and sensitivities achievable with current technology. Using a projection FFL MPI system, we examine coil hardware options and their implications for sensitivity and spatial resolution. We estimate that an fMPI brain scanner is feasible, although with reduced sensitivity (20×) and spatial resolution (5×) compared to existing rodent systems. Nonetheless, it retains sufficient sensitivity and spatial resolution to make it an attractive future instrument for studying the human brain; additional technical innovations can result in further improvements.
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spelling pubmed-55264642017-07-25 Design analysis of an MPI human functional brain scanner Mason, Erica E. Cooley, Clarissa Z. Cauley, Stephen F. Griswold, Mark A. Conolly, Steven M. Wald, Lawrence L. Int J Magn Part Imaging Article MPI’s high sensitivity makes it a promising modality for imaging brain function. Functional contrast is proposed based on blood SPION concentration changes due to Cerebral Blood Volume (CBV) increases during activation, a mechanism utilized in fMRI studies. MPI offers the potential for a direct and more sensitive measure of SPION concentration, and thus CBV, than fMRI. As such, fMPI could surpass fMRI in sensitivity, enhancing the scientific and clinical value of functional imaging. As human-sized MPI systems have not been attempted, we assess the technical challenges of scaling MPI from rodent to human brain. We use a full-system MPI simulator to test arbitrary hardware designs and encoding practices, and we examine tradeoffs imposed by constraints that arise when scaling to human size as well as safety constraints (PNS and central nervous system stimulation) not considered in animal scanners, thereby estimating spatial resolutions and sensitivities achievable with current technology. Using a projection FFL MPI system, we examine coil hardware options and their implications for sensitivity and spatial resolution. We estimate that an fMPI brain scanner is feasible, although with reduced sensitivity (20×) and spatial resolution (5×) compared to existing rodent systems. Nonetheless, it retains sufficient sensitivity and spatial resolution to make it an attractive future instrument for studying the human brain; additional technical innovations can result in further improvements. 2017-03-23 2017 /pmc/articles/PMC5526464/ /pubmed/28752130 http://dx.doi.org/10.18416/ijmpi.2017.1703008 Text en http://creativecommons.org/licenses/by/4.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Article
Mason, Erica E.
Cooley, Clarissa Z.
Cauley, Stephen F.
Griswold, Mark A.
Conolly, Steven M.
Wald, Lawrence L.
Design analysis of an MPI human functional brain scanner
title Design analysis of an MPI human functional brain scanner
title_full Design analysis of an MPI human functional brain scanner
title_fullStr Design analysis of an MPI human functional brain scanner
title_full_unstemmed Design analysis of an MPI human functional brain scanner
title_short Design analysis of an MPI human functional brain scanner
title_sort design analysis of an mpi human functional brain scanner
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5526464/
https://www.ncbi.nlm.nih.gov/pubmed/28752130
http://dx.doi.org/10.18416/ijmpi.2017.1703008
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