TY - JOUR
T1 - High-resolution multi-parametric quantitative magnetic resonance imaging of the human cervical spinal cord at 7T
AU - Massire, Aurélien
AU - Taso, Manuel
AU - Besson, Pierre
AU - Guye, Maxime
AU - Ranjeva, Jean Philippe
AU - Callot, Virginie
N1 - Funding Information:
None of the authors have potential conflicts of interest to disclose. This work was supported by the following funding sources: 7T-AMI ANR-11-EQPX-0001 , A*MIDEX-EI-13-07-130115-08.38-7T-AMISTART, A*MIDEX ANR-11-IDEX-0001-02 , and CNRS (Centre National de la Recherche Scientifique) . The authors would like to thank Mark Bydder, Benjamin Robert and Olivier Girard for helpful discussions and valuable support; Tobias Kober (MP2RAGE) and Thorsten Feiweier (DTI) from Siemens Healthcare for MR sequence support; and Véronique Gimenez, Elisabeth Soulier and Lauriane Pini for study logistics.
PY - 2016/12/1
Y1 - 2016/12/1
N2 - Quantitative MRI techniques have the potential to characterize spinal cord tissue impairments occurring in various pathologies, from both microstructural and functional perspectives. By enabling very high image resolution and enhanced tissue contrast, ultra-high field imaging may offer further opportunities for such characterization. In this study, a multi-parametric high-resolution quantitative MRI protocol is proposed to characterize in vivo the human cervical spinal cord at 7T. Multi-parametric quantitative MRI acquizitions including T1, T2 * relaxometry mapping and axial diffusion MRI were performed on ten healthy volunteers with a whole-body 7T system using a commercial prototype coil-array dedicated to cervical spinal cord imaging. Automatic cord segmentation and multi-parametric data registration to spinal cord templates enabled robust regional studies within atlas-based WM tracts and GM horns at the C3 cervical level. T1 value, cross-sectional area and GM/WM ratio evolutions along the cervical cord were also reported. An original correction method for B1 +-biased T1 mapping sequence was additionally proposed and validated on phantom. As a result, relaxometry and diffusion parameters derived from high-resolution quantitative MRI acquizitions were reported at 7T for the first time. Obtained images, with unmatched resolutions compared to lower field investigations, provided exquisite anatomical details and clear delineation of the spinal cord substructures within an acquisition time of 30 min, compatible with clinical investigations. Regional statistically significant differences were highlighted between WM and GM based on T1 and T2* maps (p<10−3), as well as between sensory and motor tracts based on diffusion tensor imaging maps (p<0.05). The proposed protocol demonstrates that ultra-high field spinal cord high-resolution quantitative MRI is feasible and lays the groundwork for future clinical investigations of degenerative spinal cord pathologies.
AB - Quantitative MRI techniques have the potential to characterize spinal cord tissue impairments occurring in various pathologies, from both microstructural and functional perspectives. By enabling very high image resolution and enhanced tissue contrast, ultra-high field imaging may offer further opportunities for such characterization. In this study, a multi-parametric high-resolution quantitative MRI protocol is proposed to characterize in vivo the human cervical spinal cord at 7T. Multi-parametric quantitative MRI acquizitions including T1, T2 * relaxometry mapping and axial diffusion MRI were performed on ten healthy volunteers with a whole-body 7T system using a commercial prototype coil-array dedicated to cervical spinal cord imaging. Automatic cord segmentation and multi-parametric data registration to spinal cord templates enabled robust regional studies within atlas-based WM tracts and GM horns at the C3 cervical level. T1 value, cross-sectional area and GM/WM ratio evolutions along the cervical cord were also reported. An original correction method for B1 +-biased T1 mapping sequence was additionally proposed and validated on phantom. As a result, relaxometry and diffusion parameters derived from high-resolution quantitative MRI acquizitions were reported at 7T for the first time. Obtained images, with unmatched resolutions compared to lower field investigations, provided exquisite anatomical details and clear delineation of the spinal cord substructures within an acquisition time of 30 min, compatible with clinical investigations. Regional statistically significant differences were highlighted between WM and GM based on T1 and T2* maps (p<10−3), as well as between sensory and motor tracts based on diffusion tensor imaging maps (p<0.05). The proposed protocol demonstrates that ultra-high field spinal cord high-resolution quantitative MRI is feasible and lays the groundwork for future clinical investigations of degenerative spinal cord pathologies.
KW - Diffusion tensor imaging
KW - Quantitative MRI
KW - Relaxometry mapping
KW - Spinal cord
KW - Template-based segmentation
KW - Ultra-high field
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U2 - 10.1016/j.neuroimage.2016.08.055
DO - 10.1016/j.neuroimage.2016.08.055
M3 - Article
C2 - 27574985
AN - SCOPUS:84988026100
VL - 143
SP - 58
EP - 69
JO - NeuroImage
JF - NeuroImage
SN - 1053-8119
ER -
