Contributions
Abstract: P538
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - 21 Imaging
Background: White matter lesions (WML) in brain MRI play a major role in diagnosing and monitoring disease activity in Clinically Isolated Syndrome (CIS) and Multiple Sclerosis (MS). Diagnostic criteria have stipulated a minimal diameter (d) of 3mm (Polmann, 2005). However, there is no evidence with regard to the minimal meaningful WML size, which might have changed over the past years, given the trend towards more frequent application of three-dimensional (3D) sequences at 3 Tesla (T). Moreover, small T2w-hyperintensities (T2wHI) may also occur in healthy controls (HC) and not necessarily reflect WML. This study compared the distribution and sizes of T2wHI between healthy controls (HC) and patients with CIS or MS.
Methods: 3D T1-weighted and FLAIR sequences were obtained at 3T from 120 patients with CIS or MS (disease duration 3.06+/-4.28 years; EDSS 1.33+/-0.91) and in 114 age-matched HC. Volume (V) and number of T2wHI were extracted by an automated lesion segmentation tool (LST version 2.0.15). Odds ratios (OR) across T2wHI volume (V) were calculated. Further, we estimated the power of small T2wHI to discriminate between CIS/MS patients and HC by a receiver operating characteristic curve.
Results: We found T2wHI in the MS and HC group. With decreasing size, the number of T2wHI continuously increased in both groups. Across all sizes, T2wHI were more frequent in CIS/MS patients. OR across T2wHI size increased continuously with OR=2.1 at V=0.015ml (d≈3mm), OR=2.5 at V=0.050ml (d≈5mm), and OR=3.3 at V=0.1ml (d≈6mm). In HC, T2wHI number asymptotically approached zero at V=0.2ml; for lesions with V< 0.2ml (d< 7mm), discriminative power was best at V=0.011ml; however sensitivity (0.58) and specificity (0.63) were low.
Conclusions: We did not find further meaningful discriminative power of lesions with d< 3mm. Given the OR of 2, a minimal diameter of 3mm seems a reasonable choice also for state-of-the-art 3D MRI sequences at 3T.
Disclosure: This work was funded by the 'German Competence Network Multiple Sclerosis' (German Ministry for Research and Education, grant 01GI1604A).
Sophia Grahl has nothing to disclose.
Viola Biberacher has nothing to disclose.
Paul Schmidt has nothing to disclose.
Christina Engl has nothing to disclose.
Annkathrin Beer has nothing to disclose.
Jan Kirschke has nothing to disclose.
Claus Zimmer has nothing to disclose.
Bernhard Hemmer has served on scientific advisory boards for F. Hoffmann-La Roche Ltd, Novartis, Bayer AG, and Genentech; he has served as DMSC member for AllergyCare; he or his institution have received speaker honoraria from Biogen Idec, Teva Neuroscience, Merck Serono, Medimmune, Novartis, Desitin, and F. Hoffmann-La Roche Ltd; his institution has received research support from Chugai Pharmaceuticals and Hoffmann-La-Roche; holds part of two patents; one for the detection of antibodies and T cells against KIR4.1 in a subpopulation of MS patients and one for genetic determinants of neutralizing antibodies to interferon β.
Mark Mühlau received research support from Merck Serono and Novartis.
Abstract: P538
Type: Poster
Abstract Category: Pathology and pathogenesis of MS - 21 Imaging
Background: White matter lesions (WML) in brain MRI play a major role in diagnosing and monitoring disease activity in Clinically Isolated Syndrome (CIS) and Multiple Sclerosis (MS). Diagnostic criteria have stipulated a minimal diameter (d) of 3mm (Polmann, 2005). However, there is no evidence with regard to the minimal meaningful WML size, which might have changed over the past years, given the trend towards more frequent application of three-dimensional (3D) sequences at 3 Tesla (T). Moreover, small T2w-hyperintensities (T2wHI) may also occur in healthy controls (HC) and not necessarily reflect WML. This study compared the distribution and sizes of T2wHI between healthy controls (HC) and patients with CIS or MS.
Methods: 3D T1-weighted and FLAIR sequences were obtained at 3T from 120 patients with CIS or MS (disease duration 3.06+/-4.28 years; EDSS 1.33+/-0.91) and in 114 age-matched HC. Volume (V) and number of T2wHI were extracted by an automated lesion segmentation tool (LST version 2.0.15). Odds ratios (OR) across T2wHI volume (V) were calculated. Further, we estimated the power of small T2wHI to discriminate between CIS/MS patients and HC by a receiver operating characteristic curve.
Results: We found T2wHI in the MS and HC group. With decreasing size, the number of T2wHI continuously increased in both groups. Across all sizes, T2wHI were more frequent in CIS/MS patients. OR across T2wHI size increased continuously with OR=2.1 at V=0.015ml (d≈3mm), OR=2.5 at V=0.050ml (d≈5mm), and OR=3.3 at V=0.1ml (d≈6mm). In HC, T2wHI number asymptotically approached zero at V=0.2ml; for lesions with V< 0.2ml (d< 7mm), discriminative power was best at V=0.011ml; however sensitivity (0.58) and specificity (0.63) were low.
Conclusions: We did not find further meaningful discriminative power of lesions with d< 3mm. Given the OR of 2, a minimal diameter of 3mm seems a reasonable choice also for state-of-the-art 3D MRI sequences at 3T.
Disclosure: This work was funded by the 'German Competence Network Multiple Sclerosis' (German Ministry for Research and Education, grant 01GI1604A).
Sophia Grahl has nothing to disclose.
Viola Biberacher has nothing to disclose.
Paul Schmidt has nothing to disclose.
Christina Engl has nothing to disclose.
Annkathrin Beer has nothing to disclose.
Jan Kirschke has nothing to disclose.
Claus Zimmer has nothing to disclose.
Bernhard Hemmer has served on scientific advisory boards for F. Hoffmann-La Roche Ltd, Novartis, Bayer AG, and Genentech; he has served as DMSC member for AllergyCare; he or his institution have received speaker honoraria from Biogen Idec, Teva Neuroscience, Merck Serono, Medimmune, Novartis, Desitin, and F. Hoffmann-La Roche Ltd; his institution has received research support from Chugai Pharmaceuticals and Hoffmann-La-Roche; holds part of two patents; one for the detection of antibodies and T cells against KIR4.1 in a subpopulation of MS patients and one for genetic determinants of neutralizing antibodies to interferon β.
Mark Mühlau received research support from Merck Serono and Novartis.