Contributions
Abstract: EP1521
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 21 Imaging
Introduction: Myelin water fraction (MWF) is an imaging biomarker for myelin, acquired by an advanced MRI technique known as myelin water imaging (MWI) and traditionally derived using a lengthy multi-echo T2 sequence. Spinal cord (SC) application of MWI has been hindered by difficulties intrinsic to cord imaging. GRASE, a MWI acquisition technique accelerated by a factor of 3, has recently been implemented with high resolution and low acquisition time in healthy and injured SC.
Objective: Investigate the myelin content in the cervical SC of patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) using GRASE MWI.
Methods: GRASE data centred at the C2/C3 disk level was collected from 8 healthy controls and 4 patients (1 relapsing-remitting MS (RRMS, EDSS=2.0); 1 primary-progressive MS (PPMS, EDSS=6.0); 2 NMOSD (EDSS=2.0 and 1.0)). Conventional anatomical MRI images facilitated analysis of MWF within regions of interest (ROI): whole cord (WC), white matter (WM), gray matter (GM), dorsal column (DC) and lateral funiculi (LF). Due to the exploratory, case study nature of the project, MWF results differing by >1 standard deviation (σ) from HC mean were termed either high or low.
Results: Two patients had cervical SC lesions in the MWI field of view; RRMS had a small eccentric cord lesion and one of the NMOSD had a large transverse myelitis (TM) lesion. HC showed MWF variations between ROIs and agreement with literature (WC mean/σ=24.3/1.9%, WM=26.4/1.9%, GM=16.0/2.5%, DC=28.2/2.5%, LF=25.4/1.8%). NMOSD #1 with TM had drastically reduced MWF in all ROIs (WC=12.8, WM=14.0, GM=6.3, DC=6.9, LF=16.0%). NMOSD #2 had low MWF in all ROIs except the LF (WC=22.1, WM=23.9, GM=12.7, DC=24.1, LF=24.5%) despite lack of lesions. The MWF for the RRMS patient was similar to HC in WC, WM and GM ROI (WC=24.4, WM=25.9, GM=17.5%), but high in the DC (DC=31.0%) and low in the LF corresponding to lesion location (LF=23.1%). MWF values for the PPMS patient were similar to HC in all ROI (WC=25.1, WM=27.4, GM=16.8, DC=29.3, LF=25.5%).
Conclusion: GRASE MWI characterized healthy SC myelin content in agreement with literature values, and demonstrated reduced myelin water in TM lesion tissue. MWF values were reduced in NMOSD, regardless of visible lesions on conventional MRI, and suggested focal demyelination in RRMS lesion. These results support the clinical feasibility of using GRASE SC MWI as a potential quantitative measure of disease related myelin changes.
Disclosure:
A. Dvorak: has nothing to disclose.
E. Ljungberg: has received PhD funding from GE Healthcare.
I. Vavasour: has nothing to disclose.
H. Liu: has nothing to disclose.
A. Rauscher: has nothing to disclose.
J. Kramer: has nothing to disclose.
C. Laule: has nothing to disclose.
A. MacKay: has nothing to disclose.
A. Traboulsee: has received research support from Biogen, Chugai, CIHR, Roche, Michael Smith Foundation and MS Society of Canada, and has consulted for Biogen, Roche, EMD Serono and Teva Pharmaceuticals.
P. Kozlowski: has nothing to disclose.
S. Kolind: has received research support from Roche and MS Society of Canada, and has consulted for Acorda, Genzyme.
Abstract: EP1521
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 21 Imaging
Introduction: Myelin water fraction (MWF) is an imaging biomarker for myelin, acquired by an advanced MRI technique known as myelin water imaging (MWI) and traditionally derived using a lengthy multi-echo T2 sequence. Spinal cord (SC) application of MWI has been hindered by difficulties intrinsic to cord imaging. GRASE, a MWI acquisition technique accelerated by a factor of 3, has recently been implemented with high resolution and low acquisition time in healthy and injured SC.
Objective: Investigate the myelin content in the cervical SC of patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) using GRASE MWI.
Methods: GRASE data centred at the C2/C3 disk level was collected from 8 healthy controls and 4 patients (1 relapsing-remitting MS (RRMS, EDSS=2.0); 1 primary-progressive MS (PPMS, EDSS=6.0); 2 NMOSD (EDSS=2.0 and 1.0)). Conventional anatomical MRI images facilitated analysis of MWF within regions of interest (ROI): whole cord (WC), white matter (WM), gray matter (GM), dorsal column (DC) and lateral funiculi (LF). Due to the exploratory, case study nature of the project, MWF results differing by >1 standard deviation (σ) from HC mean were termed either high or low.
Results: Two patients had cervical SC lesions in the MWI field of view; RRMS had a small eccentric cord lesion and one of the NMOSD had a large transverse myelitis (TM) lesion. HC showed MWF variations between ROIs and agreement with literature (WC mean/σ=24.3/1.9%, WM=26.4/1.9%, GM=16.0/2.5%, DC=28.2/2.5%, LF=25.4/1.8%). NMOSD #1 with TM had drastically reduced MWF in all ROIs (WC=12.8, WM=14.0, GM=6.3, DC=6.9, LF=16.0%). NMOSD #2 had low MWF in all ROIs except the LF (WC=22.1, WM=23.9, GM=12.7, DC=24.1, LF=24.5%) despite lack of lesions. The MWF for the RRMS patient was similar to HC in WC, WM and GM ROI (WC=24.4, WM=25.9, GM=17.5%), but high in the DC (DC=31.0%) and low in the LF corresponding to lesion location (LF=23.1%). MWF values for the PPMS patient were similar to HC in all ROI (WC=25.1, WM=27.4, GM=16.8, DC=29.3, LF=25.5%).
Conclusion: GRASE MWI characterized healthy SC myelin content in agreement with literature values, and demonstrated reduced myelin water in TM lesion tissue. MWF values were reduced in NMOSD, regardless of visible lesions on conventional MRI, and suggested focal demyelination in RRMS lesion. These results support the clinical feasibility of using GRASE SC MWI as a potential quantitative measure of disease related myelin changes.
Disclosure:
A. Dvorak: has nothing to disclose.
E. Ljungberg: has received PhD funding from GE Healthcare.
I. Vavasour: has nothing to disclose.
H. Liu: has nothing to disclose.
A. Rauscher: has nothing to disclose.
J. Kramer: has nothing to disclose.
C. Laule: has nothing to disclose.
A. MacKay: has nothing to disclose.
A. Traboulsee: has received research support from Biogen, Chugai, CIHR, Roche, Michael Smith Foundation and MS Society of Canada, and has consulted for Biogen, Roche, EMD Serono and Teva Pharmaceuticals.
P. Kozlowski: has nothing to disclose.
S. Kolind: has received research support from Roche and MS Society of Canada, and has consulted for Acorda, Genzyme.