Contributions
Abstract: P1036
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - Imaging
Introduction: The North American Imaging in Multiple Sclerosis (NAIMS) Cooperative was formed with the goal of developing sensitive, reliable imaging-based surrogates for disease progression in MS. The current lack of standardization in MRI protocols leads to increased variability, particularly in semi-quantitative techniques such as MTR, and makes comparisons between studies almost impossible. These efforts will accelerate MS research by creating standardized quantitative imaging protocols, a centralized database, multiple analytic tools, and data sharing across NAIMS sites.
Methods: A single subject with clinically stable RRMS travelled to seven North American sites and underwent two distinct 3T MRI sessions following a standardized protocol at each site. Informed consent was obtained at each imaging center. The variable flip angle (FA) method (FA 3°, 6°, 10°, 20°) was employed to create whole-brain quantitative T1 (qT1) maps. Magnetization transfer images were acquired with two saturation pulse offset frequencies (4kHz, 100kHz) at 8 mT amplitude, sufficient for magnetization transfer ratio (MTR) calculation.
Results: Imaging sessions were successfully completed at all sites between October 2015 and February 2016. MTR maps were of similar quality (characterized by signal-to-noise ratio, homogeneity) across all sites. Mean (±standard deviation) white matter, cortical grey matter, and lesion MTR values for all imaging sessions were: 0.27 (0.005), 0.20 (0.009), and 0.21 (0.006), respectively. Mean intra-session MTR variance was 0.0001 across all sites. Despite applying corrections, B1 inhomogeneity contributed to substantial inconsistencies in qT1 maps, particularly in the most superior and inferior regions of the brain where radio frequency coil performance is variable and sensitive to subject placement within the instrument.
Discussion: Both MTR and qT1 mapping have been shown to have potential in elucidating tissue characteristics and underlying pathology. MTR is effectively a self-bias-correcting technique and demonstrated greater reproducibility across sites than did qT1 mapping. This work demonstrated that use of carefully standardized protocols produces consistent quantitative and semi-quantitative measurements across sites in MS brain tissue in-vivo. Future work will combine the qT1 and MTR maps for quantitative calculations of macromolecular fraction.
Disclosure: Ian Tagge is funded by the Race to Erase MS Fund and NINDS and has nothing to disclose.
Daniel Schwartz is funded by Race to Erase MS Fund and has nothing to disclose.
Katherine Powers is funded by Race to Erase MS Fund and has nothing to disclose.
William Rooney is funded by the Race to Erase MS Fund and has nothing to disclose.
Jack Simon has nothing to disclose.
Rohit Bakshi is funded by the Race to Erase MS Fund and has received consulting fees from AbbVie, EMD Serono, Genentech, and Novartis, received research support from Biogen, EMD-Serono, Novartis, and Sanofi-Genzyme, and serves as Editor-in-Chief of the Journal of Neuroimaging.
Govind Nair is funded by Intramural Research Program, NINDS and has nothing to disclose.
Peter Calabresi is funded by NIH R01 NS082347 - Imaging neurodegeneration in multiple sclerosis, and has received grants to Johns Hopkins from Biogen, Novartis, and MedImmune, and has received honoraria for consulting from Vertex.
John Grinstead is a Siemens Healthcare employee and has nothing to disclose.
Roland Henry recieves funding from NIH, DOD, and Roche/Genentech, and nothing to disclose.
Jiwon Oh has received research funding from Multiple Sclerosis Society of Canada, Sanofi- Genzyme, and Biogen-Idec, and has received fees for consulting or speaking from EMD-Serono, Genzyme, Biogen-Idec, Novartis, Teva, and Roche.
Nico Papinutto has no funding and nothing to disclose.
Daniel Pelletier has no funding and has received consulting honoraria from Biogen, Sanofi-Genzyme, Novartis, EMD-Serono, Vertex, and Roche.
Daniel S. Reich recieves research funding from Intramural Research Program of NINDS, Myelin Repair Foundation, and Vertex Pharmaceuticals and has nothing to disclose.
Nancy Sicotte recieves funding from National MS Society and Guthy-Jackson Charitable Foundation and has nothing to disclose.
William Stern recieves no funding and has nothing to disclose.
Nico Papinutto receives no funding and has nothing to disclose.
Todd Constable receives no funding and has nothing to disclose.
Abstract: P1036
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - Imaging
Introduction: The North American Imaging in Multiple Sclerosis (NAIMS) Cooperative was formed with the goal of developing sensitive, reliable imaging-based surrogates for disease progression in MS. The current lack of standardization in MRI protocols leads to increased variability, particularly in semi-quantitative techniques such as MTR, and makes comparisons between studies almost impossible. These efforts will accelerate MS research by creating standardized quantitative imaging protocols, a centralized database, multiple analytic tools, and data sharing across NAIMS sites.
Methods: A single subject with clinically stable RRMS travelled to seven North American sites and underwent two distinct 3T MRI sessions following a standardized protocol at each site. Informed consent was obtained at each imaging center. The variable flip angle (FA) method (FA 3°, 6°, 10°, 20°) was employed to create whole-brain quantitative T1 (qT1) maps. Magnetization transfer images were acquired with two saturation pulse offset frequencies (4kHz, 100kHz) at 8 mT amplitude, sufficient for magnetization transfer ratio (MTR) calculation.
Results: Imaging sessions were successfully completed at all sites between October 2015 and February 2016. MTR maps were of similar quality (characterized by signal-to-noise ratio, homogeneity) across all sites. Mean (±standard deviation) white matter, cortical grey matter, and lesion MTR values for all imaging sessions were: 0.27 (0.005), 0.20 (0.009), and 0.21 (0.006), respectively. Mean intra-session MTR variance was 0.0001 across all sites. Despite applying corrections, B1 inhomogeneity contributed to substantial inconsistencies in qT1 maps, particularly in the most superior and inferior regions of the brain where radio frequency coil performance is variable and sensitive to subject placement within the instrument.
Discussion: Both MTR and qT1 mapping have been shown to have potential in elucidating tissue characteristics and underlying pathology. MTR is effectively a self-bias-correcting technique and demonstrated greater reproducibility across sites than did qT1 mapping. This work demonstrated that use of carefully standardized protocols produces consistent quantitative and semi-quantitative measurements across sites in MS brain tissue in-vivo. Future work will combine the qT1 and MTR maps for quantitative calculations of macromolecular fraction.
Disclosure: Ian Tagge is funded by the Race to Erase MS Fund and NINDS and has nothing to disclose.
Daniel Schwartz is funded by Race to Erase MS Fund and has nothing to disclose.
Katherine Powers is funded by Race to Erase MS Fund and has nothing to disclose.
William Rooney is funded by the Race to Erase MS Fund and has nothing to disclose.
Jack Simon has nothing to disclose.
Rohit Bakshi is funded by the Race to Erase MS Fund and has received consulting fees from AbbVie, EMD Serono, Genentech, and Novartis, received research support from Biogen, EMD-Serono, Novartis, and Sanofi-Genzyme, and serves as Editor-in-Chief of the Journal of Neuroimaging.
Govind Nair is funded by Intramural Research Program, NINDS and has nothing to disclose.
Peter Calabresi is funded by NIH R01 NS082347 - Imaging neurodegeneration in multiple sclerosis, and has received grants to Johns Hopkins from Biogen, Novartis, and MedImmune, and has received honoraria for consulting from Vertex.
John Grinstead is a Siemens Healthcare employee and has nothing to disclose.
Roland Henry recieves funding from NIH, DOD, and Roche/Genentech, and nothing to disclose.
Jiwon Oh has received research funding from Multiple Sclerosis Society of Canada, Sanofi- Genzyme, and Biogen-Idec, and has received fees for consulting or speaking from EMD-Serono, Genzyme, Biogen-Idec, Novartis, Teva, and Roche.
Nico Papinutto has no funding and nothing to disclose.
Daniel Pelletier has no funding and has received consulting honoraria from Biogen, Sanofi-Genzyme, Novartis, EMD-Serono, Vertex, and Roche.
Daniel S. Reich recieves research funding from Intramural Research Program of NINDS, Myelin Repair Foundation, and Vertex Pharmaceuticals and has nothing to disclose.
Nancy Sicotte recieves funding from National MS Society and Guthy-Jackson Charitable Foundation and has nothing to disclose.
William Stern recieves no funding and has nothing to disclose.
Nico Papinutto receives no funding and has nothing to disclose.
Todd Constable receives no funding and has nothing to disclose.