Introduction: This study investigates the application of texture analysis methods on brain T2-white matter lesions detected with magnetic resonance imaging (MRI) for the prognosis of futuredisability in subjects diagnosed with clinical isolated syndrome (CIS) of multiple sclerosis (MS).
Methods: Brain lesions and normal appearing white matter (NAWM) from 38 symptomaticuntreated subjects diagnosed with CIS as well as normal white matter (NWM) from 20 healthyvolunteers, were manually segmented, by an experienced MS neurologist, on transverse T2-weighted images obtained from serial brain MR imaging scans (0 and 6—12 months). Additionalclinical information in the form of the Expanded Disability Status Scale (EDSS), a scale from0 to 10, which provides a way of quantifying disability in MS and monitoring the changes overtime in the level of disability, were also provided. Shape and most importantly different tex-ture features including GLCM and laws were then extracted for all above regions, after imageintensity normalization.
Results: The findings showed that: (i) there were significant differences for the texture futuresextracted between the NAWM and lesions at 0 month and between NAWM and lesions at6—12 months. However, no significant differences were found for all texture features extractedwhen comparing lesions temporally at 0 and 6—12 months with the exception of contrast (graylevel difference statistics-GLDS) and difference entropy (spatial gray level dependence matrix-SGLDM); (ii) significant differences were found between NWM and NAWM for most of the texturefeatures investigated in this study; (iii) there were significant differences found for the lesion texture features at 0 month for those with EDSS ≤ 2 versus those with EDSS > 2 (mean, median,inverse difference moment and sum average) and for the lesion texture features at 6—12 monthswith EDSS > 2 and EDSS ≤ 2 for the texture features (mean, median, entropy and sum average).It should be noted that whilst there were no differences in entropy at time 0 between the twogroups, significant change was observed at 6—12 months, relating the corresponding featuresto the follow-up and disability (EDSS) progression. For the NAWM, significant differences werefound between 0 month and 6—12 months with EDSS ≤ 2 (contrast, inverse difference moment),for 6—12 months for EDSS > 2 and 0 month with EDSS > 2 (difference entropy) and for 6—12 monthsfor EDSS > 2 and EDSS ≤ 2 (sum average); (iv) there was no significant difference for NAWM andthe lesion texture features (for both 0 and 6—12 months) for subjects with no change in EDSSscore versus subjects with increased EDSS score from 2 to 5 years.
Conclusions: The findings of this study provide evidence that texture features of T2 MRI brainwhite matter lesions may have an additional potential role in the clinical evaluation of MRIimages in MS and perhaps may provide some prognostic evidence in relation to future disabilityof patients. However, a larger scale study is needed to establish the application in clinicalpractice and for computing shape and texture features that may provide information for betterand earlier differentiation between normal brain tissue and MS lesions.