Contributions
Abstract: EP1536
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 21 Imaging
Purpose: To use advanced magnetic resonance imaging (MRI) to determine whether neuromyelitis optica (NMO) brain lesions exhibit different distributions of myelin damage or water content compared to multiple sclerosis (MS).
Introduction: MS and NMO are distinct inflammatory diseases that are similar in clinical presentation. NMO and MS lesions can appear similar on conventional MRI. Aquaporin channels are primarily affected in NMO, thus water distributions may differ between diseases. Due to different mechanisms of inflammation, the patterns of demyelination may also diverge in NMO lesions compared to MS. An advanced MRI technique, multi-echo T2 relaxation imaging, was used to quantify the total water content (WC) and myelin (myelin water fraction (MWF)) in NMO and MS lesions.
Methods: Ten NMO (mean age: 42y, median EDSS: 2.5), 13 MS (41y, EDSS: 2.5), and 15 healthy controls (41y) underwent MRI on a Philips 3T scanner. The healthy control data was used to create normative 3D atlases of the means and standard deviations of WC and MWF. The atlases were used to calculate Z-score maps for each MS and NMO patient, indicating how many standard deviations away from the mean each value is for an individual patient compared to controls. NMO and MS lesions were identified on conventional images by a radiologist. The areas within lesions were analysed on the Z-score maps and histogram analysis was performed.
Results: The histograms for WC and MWF Z-scores were visually similar for NMO (average of Z-score means: WC: +3.2; MWF: -0.8) and MS lesions (WC: +2.3; MWF: -1.2). There was no difference between NMO and MS average Z-scores for WC (Student's t-test) (p=0.30) or MWF (p=0.31). The distribution of values within lesions was visualized using heat maps. The WC values were distributed with higher values near the centre of the lesions, while the MWF values had lower values near the centre. This pattern held true for both diseases.
Discussion: While the pathophysiology of MS and NMO are different, the lesions appear to be very similar in terms of their WC and MWF values. WC was higher, while MWF was lower in lesions when compared to the same regions in healthy controls. The distribution of values within lesions was also similar, where there is higher WC and lower MWF towards the centre of a lesion. This suggests that there is less myelin in the middle of lesions compared to the periphery. Overall, our results show that NMO and MS lesions are similar in terms of WC and MWF.
Disclosure:
A.B. Soares: no disclosures
I.M. Vavasour: no disclosures
A. Combes: no disclosures
S.M. Meyers: no disclosures
P. Manogaran: received travel support from Sanofi Genzyme
S. Xiao: funding from the German Academic Exchange Service (DAAD)
A. Wurl: funding by Deutscher Akademischer Austauschdienst (DAAD)
D.K.B. Li: received research funding from the Canadian Institute of Health Research and Multiple Sclerosis Society of Canada. He is the Emeritus Director of the UBC MS/MRI Research Group which has been contracted to perform central analysis of MRI scans for therapeutic trials with Novartis, Perceptives, Roche and Sanofi-Aventis. The UBC MS/MRI Research Group has also received grant support for investigator-initiated independent studies from Genzyme, Merck-Serono, Novartis and Roche. He has acted as a consultant to Vertex Pharmaceuticals and served on the Data and Safety Advisory Board for Opexa Therapeutics and Scientific Advisory Boards for Adelphi Group, Novartis and Roche. He has given lectures which have been supported by non-restricted education grants from Novartis and Biogen.
A.L. Traboulsee: consulting: Biogen, Roche, EMD Serono, Teva Pharmaceuticals; research support: Biogen, Chugai, CIHR, Roche, Michael Smith Foundation, MS Society of Canada
S.H. Kolind: research support from Roche, MS Society of Canada; consulting for Acorda, Genzyme.
Abstract: EP1536
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 21 Imaging
Purpose: To use advanced magnetic resonance imaging (MRI) to determine whether neuromyelitis optica (NMO) brain lesions exhibit different distributions of myelin damage or water content compared to multiple sclerosis (MS).
Introduction: MS and NMO are distinct inflammatory diseases that are similar in clinical presentation. NMO and MS lesions can appear similar on conventional MRI. Aquaporin channels are primarily affected in NMO, thus water distributions may differ between diseases. Due to different mechanisms of inflammation, the patterns of demyelination may also diverge in NMO lesions compared to MS. An advanced MRI technique, multi-echo T2 relaxation imaging, was used to quantify the total water content (WC) and myelin (myelin water fraction (MWF)) in NMO and MS lesions.
Methods: Ten NMO (mean age: 42y, median EDSS: 2.5), 13 MS (41y, EDSS: 2.5), and 15 healthy controls (41y) underwent MRI on a Philips 3T scanner. The healthy control data was used to create normative 3D atlases of the means and standard deviations of WC and MWF. The atlases were used to calculate Z-score maps for each MS and NMO patient, indicating how many standard deviations away from the mean each value is for an individual patient compared to controls. NMO and MS lesions were identified on conventional images by a radiologist. The areas within lesions were analysed on the Z-score maps and histogram analysis was performed.
Results: The histograms for WC and MWF Z-scores were visually similar for NMO (average of Z-score means: WC: +3.2; MWF: -0.8) and MS lesions (WC: +2.3; MWF: -1.2). There was no difference between NMO and MS average Z-scores for WC (Student's t-test) (p=0.30) or MWF (p=0.31). The distribution of values within lesions was visualized using heat maps. The WC values were distributed with higher values near the centre of the lesions, while the MWF values had lower values near the centre. This pattern held true for both diseases.
Discussion: While the pathophysiology of MS and NMO are different, the lesions appear to be very similar in terms of their WC and MWF values. WC was higher, while MWF was lower in lesions when compared to the same regions in healthy controls. The distribution of values within lesions was also similar, where there is higher WC and lower MWF towards the centre of a lesion. This suggests that there is less myelin in the middle of lesions compared to the periphery. Overall, our results show that NMO and MS lesions are similar in terms of WC and MWF.
Disclosure:
A.B. Soares: no disclosures
I.M. Vavasour: no disclosures
A. Combes: no disclosures
S.M. Meyers: no disclosures
P. Manogaran: received travel support from Sanofi Genzyme
S. Xiao: funding from the German Academic Exchange Service (DAAD)
A. Wurl: funding by Deutscher Akademischer Austauschdienst (DAAD)
D.K.B. Li: received research funding from the Canadian Institute of Health Research and Multiple Sclerosis Society of Canada. He is the Emeritus Director of the UBC MS/MRI Research Group which has been contracted to perform central analysis of MRI scans for therapeutic trials with Novartis, Perceptives, Roche and Sanofi-Aventis. The UBC MS/MRI Research Group has also received grant support for investigator-initiated independent studies from Genzyme, Merck-Serono, Novartis and Roche. He has acted as a consultant to Vertex Pharmaceuticals and served on the Data and Safety Advisory Board for Opexa Therapeutics and Scientific Advisory Boards for Adelphi Group, Novartis and Roche. He has given lectures which have been supported by non-restricted education grants from Novartis and Biogen.
A.L. Traboulsee: consulting: Biogen, Roche, EMD Serono, Teva Pharmaceuticals; research support: Biogen, Chugai, CIHR, Roche, Michael Smith Foundation, MS Society of Canada
S.H. Kolind: research support from Roche, MS Society of Canada; consulting for Acorda, Genzyme.