Contributions
Abstract: P1071
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - Imaging
Background and purpose: Restriction Spectrum Imaging (RSI) is a newly validated magnetic resonance imaging (MRI) technique that enables quantitative estimates of tissue microstructure based on the size and orientation of the diffusion-hindered and restricted water compartments. The technique may enable a detailed characterization of brain tissue but its clinical utility in multiple sclerosis (MS) has not been investigated. The purpose of this study was to determine the relation between diffusion parameters calculated from RSI and neurological disability in patients with MS.
Methods: MRI including the RSI sequence was performed on a 3 Tesla scanner in 82 MS patients (65 females and 17 males, mean age 40.1 ± 10.4 years) at different stages of the disease. Parameter maps representing tubularity index (TI), fractional anisotropy (FA), fast (f-ADC) and slow apparent diffusion coefficient (s-ADC) were calculated from the RSI sequence. Masks of white matter and of white matter lesions (WML) in each patient were created. The parameters were derived from the whole volume of WML and from normal appearing white matter (NAWM). Patients were divided into three subgroups according to their levels of neurological disability as measured by expanded disability status scale (EDSS) score: group 1: no or minimal disability with EDSS< 2.5; group 2: low disability with EDSS of 2.5-3; group 3: substantial disability with EDSS>3.
Results: Compared to MS patients with no or minimal disability, patients with substantial disability had lower FA (p=0.026), higher f-ADC (p=0.004) and higher s-ADC (p< 0.001) in WML. No group differences were found for TI in WML (p=0.576). In NAWM all four tested parameters differed significantly between the EDSS subgroups: patients with substantial disability had lower TI (p=0.018) and FA (p=0.009) and higher f-ADC (p=0.008) and s-ADC (p=0.018) than those with no or minimal disability. There was a significant correlation between TI in NAWM and EDSS (r=-0.4, p< 0.001).
Conclusions: TI differed between the EDSS subgroups and correlated with EDSS only when obtained in NAWM. TI obtained in NAWM varies with disability in a similar way as FA and may be useful for disease monitoring.
Abbreviations
ADC=apparent diffusion coefficient (f-ADC=fast ADC; s-ADC=slow ADC), EDSS=expanded disability status scale, FA=fractional anisotropy, NAWM=normal appearing white matter, RSI=restriction spectrum imaging, TI=tubularity index, WML=white matter lesion
Disclosure: Main source of funding: grant from South-Eastern Norway Regional Health Authority.
Piotr Sowa received honoraria for lectures from Novartis, Genzyme and Biogen Idec.
Hanne F. Harbo received an unrestricted research grant from Novartis, and support for travelling and speaking honoraria from Biogen Idec, Novartis, Sanofi-Aventis and Teva.
Elisabeth G. Celius received funding for travel and speaker"s fees from Almirall, Biogen Idec, Genzyme, Novartis, Sanofi-Aventis and Teva, and received unrestricted research grants from Biogen Idec, Genzyme and Novartis.
Pål Berg-Hansen received an unrestricted research grant from Novartis and funding for travel or speaker"s fees from Novartis, UCB and Teva.
Stine M. Moen received an unrestricted research grant from Novartis and unrestricted travel grant and speaker"s fees from Biogen Idec and Novartis.
Nathan White, Hauke Bartsch, Lars T. Westlye, Ole A. Andreassen, Anders S. Dale and Mona K. Beyer: nothing to disclose.
Abstract: P1071
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - Imaging
Background and purpose: Restriction Spectrum Imaging (RSI) is a newly validated magnetic resonance imaging (MRI) technique that enables quantitative estimates of tissue microstructure based on the size and orientation of the diffusion-hindered and restricted water compartments. The technique may enable a detailed characterization of brain tissue but its clinical utility in multiple sclerosis (MS) has not been investigated. The purpose of this study was to determine the relation between diffusion parameters calculated from RSI and neurological disability in patients with MS.
Methods: MRI including the RSI sequence was performed on a 3 Tesla scanner in 82 MS patients (65 females and 17 males, mean age 40.1 ± 10.4 years) at different stages of the disease. Parameter maps representing tubularity index (TI), fractional anisotropy (FA), fast (f-ADC) and slow apparent diffusion coefficient (s-ADC) were calculated from the RSI sequence. Masks of white matter and of white matter lesions (WML) in each patient were created. The parameters were derived from the whole volume of WML and from normal appearing white matter (NAWM). Patients were divided into three subgroups according to their levels of neurological disability as measured by expanded disability status scale (EDSS) score: group 1: no or minimal disability with EDSS< 2.5; group 2: low disability with EDSS of 2.5-3; group 3: substantial disability with EDSS>3.
Results: Compared to MS patients with no or minimal disability, patients with substantial disability had lower FA (p=0.026), higher f-ADC (p=0.004) and higher s-ADC (p< 0.001) in WML. No group differences were found for TI in WML (p=0.576). In NAWM all four tested parameters differed significantly between the EDSS subgroups: patients with substantial disability had lower TI (p=0.018) and FA (p=0.009) and higher f-ADC (p=0.008) and s-ADC (p=0.018) than those with no or minimal disability. There was a significant correlation between TI in NAWM and EDSS (r=-0.4, p< 0.001).
Conclusions: TI differed between the EDSS subgroups and correlated with EDSS only when obtained in NAWM. TI obtained in NAWM varies with disability in a similar way as FA and may be useful for disease monitoring.
Abbreviations
ADC=apparent diffusion coefficient (f-ADC=fast ADC; s-ADC=slow ADC), EDSS=expanded disability status scale, FA=fractional anisotropy, NAWM=normal appearing white matter, RSI=restriction spectrum imaging, TI=tubularity index, WML=white matter lesion
Disclosure: Main source of funding: grant from South-Eastern Norway Regional Health Authority.
Piotr Sowa received honoraria for lectures from Novartis, Genzyme and Biogen Idec.
Hanne F. Harbo received an unrestricted research grant from Novartis, and support for travelling and speaking honoraria from Biogen Idec, Novartis, Sanofi-Aventis and Teva.
Elisabeth G. Celius received funding for travel and speaker"s fees from Almirall, Biogen Idec, Genzyme, Novartis, Sanofi-Aventis and Teva, and received unrestricted research grants from Biogen Idec, Genzyme and Novartis.
Pål Berg-Hansen received an unrestricted research grant from Novartis and funding for travel or speaker"s fees from Novartis, UCB and Teva.
Stine M. Moen received an unrestricted research grant from Novartis and unrestricted travel grant and speaker"s fees from Biogen Idec and Novartis.
Nathan White, Hauke Bartsch, Lars T. Westlye, Ole A. Andreassen, Anders S. Dale and Mona K. Beyer: nothing to disclose.