Juxtacortical Lesions in Multiple Sclerosis: Assessment of Gray Matter Involvement Using Phase Difference-enhanced Imaging (PADRE)

Abstract

Purpose:In multiple sclerosis (MS), a juxtacortical lesion at the border between the gray matter (GM) and subcortical white matter (WM) may often involve the GM. A recently developed, phase-weighted magnetic resonance imaging (MRI) technique “phase difference enhanced imaging (PADRE)” can delineate the GM and WM clearly due to the difference in myelin concentration. We evaluated whether PADRE is useful for the detection of GM involvement in the juxtacortical MS lesions.Methods:One neuroradiologist reviewed the conventional MRI in 13 MS patients and selected 48 juxtacortical lesions. At the first reading session with the conventional MRI alone (T2-weighted imaging, and two-dimensional and three-dimensional fluid-attenuated inversion recovery), two other neuroradiologists classified the lesions into three patterns according to their anatomical locations: (a) subcortical WM lesions involving the subcortical WM alone; (b) intracortical (IC) lesions involving the GM alone; (c) mixed GM/subcortical WM (mixed) lesions involving the both subcortical WM and GM. We defined the subcortical WM as a WM within a distance of 10 mm from inner edge of the GM. For the analyses, we excluded the white matter lesions further than 10 mm from inner edge of the GM. At the second reading session MRI and PADRE were available and the radiologists re-evaluated their prior classification.Results:At the first reading session, 27 lesions were classified as (a), 1 as (b), and 20 as (c). Therefore, a total of 21 lesions (44%) were judged to involve the GM. At the second reading session, the classification of 15 (31%) lesions changed; all 15 lesions were judged to involve the GM on the PADRE. Interobserver agreement (kappa value) was 0.84 for the first- and 0.95 for the second reading session.Conclusion:PADRE is useful for detecting GM involvement of the juxtacortical MS lesions.

Machine learning to investigate superficial white matter integrity in early multiple sclerosis

“…41 SWM regions have also been reported as one of the predilection sites for MS lesions. 5,42,43 Previous studies investigating SWM integrity and/or lesion load in SWM regions reported correlations between imaging metrics and cognitive performance both in healthy subjects and patient populations. 4,44,45 Since SWM structural connectivity shows a leftward bias across most of the brain, 3 language function may be selectively affected by SWM microstructural damage.…”

Signal Change of Acute Cortical and Juxtacortical Microinfarction on Follow-Up MRI

“…Moreover, our lesion-by-lesion analysis demonstrated that 8 lesions rated as CMIs on SWI were rated as juxtacortical WM alone on T2WI/FLAIR, suggesting that SWI may be more accurate for assessing disease burden, especially GM involvement. In a previous study, phase-weighted MR imaging such as SWI had superior contrast between the GM and the surrounding WM, 29,30 which may contribute to improved CMI detection. However, CMIs may not be seen on T2WI/FLAIR because they can be obscured from CSF by partial volume effects.…”

Differentiation of Brain Metastases and Gliomas Based on Color Map of Phase Difference Enhanced Imaging

“…Previous studies of PADRE reported clear demonstration of normal structures, such as small fiber tracts of the brain stem ( 13 ), layers of the optic radiation, the stria of Gennari ( 16 , 17 ), gray-to-white matter interface or SWM ( 17 – 19 ) and the internal structures of the thalamus ( 14 ) with TEI. In addition, the relevance of PADRE findings to aging ( 49 ) and various pathological conditions including multiple system atrophy of the cerebellar type ( 13 ), Parkinson's disease ( 50 , 51 ), amyotrophic lateral sclerosis ( 15 ), multiple sclerosis ( 52 ) and Alzheimer's disease ( 53 ) has also been reported.…”