Dirty-appearing white matter in multiple sclerosis: volumetric MR imaging and magnetization transfer ratio histogram analysis.

BACKGROUND AND PURPOSE In contrast to "normal-appearing" white matter (NAWM) in patients with multiple sclerosis (MS), there are subtle, abnormal and diffuse signal intensity changes often seen on T2-weighted MR images, which we have referred to as "dirty-appearing" white matter (DAWM). These areas of DAWM have slightly higher signal intensity than that of NAWM, but lower than that of lesion plaques. Our study was designed to determine the volumetric and magnetization transfer ratio (MTR) features of DAWM in patients with MS. METHODS Dual-echo fast spin-echo MR imaging and magnetization transfer imaging were performed in 22 patients with relapsing-remitting MS. Slightly hyperintense DAWM areas were manually outlined on the basis of T2-weighted imaging findings. The volume and MTR of DAWM were calculated and compared with the volume and MTR of NAWM and T2 lesion plaques. RESULTS The average volume of DAWM (18.3 mL) was greater than the average volume of T2 lesion plaques (11.0 mL, P =.04), and the mean MTR in DAWM (38.7%) differed significantly (P <.0001) from that in NAWM (40.7%) and plaques (33.3%). There was a modest negative correlation between either mean MTR (r = -0.60; P =.003) of DAWM or peak height (r = -0.50; P =.02) of DAWM with T2 lesion load. Neither DAWM volume nor total T2 abnormality (DAWM + plaques) volume correlates with the Expanded Disability Status Scale. CONCLUSION The results of this study indicate that MTR is able to differentiate DAWM from lesion plaques and NAWM and that DAWM might be a different pathologic process of the disease. The notion and quantification of these subtle imaging findings of DAWM areas may improve our understanding of certain stages of disease progression and disease burden in patients with relapsing-remitting MS.

[1]  K. Suzuki,et al.  Myelin in multiple sclerosis. Composition of myelin from normal-appearing white matter. , 1973, Archives of neurology.

[2]  Remyelination in multiple sclerosis , 1979, Annals of neurology.

[3]  Dr. med. Hans Lassmann.  Comparative Neuropathology of Chronic Experimental Allergic Encephalomyelitis and Multiple Sclerosis , 1983, Schriftenreihe Neurologie / Neurology Series.

[4]  J. Kurtzke.  Rating neurologic impairment in multiple sclerosis , 1983, Neurology.

[5]  D. MacManus,et al.  Relaxation times of apparently normal cerebral white matter in multiple sclerosis. , 1986, Acta radiologica. Supplementum.

[6]  S W Atlas,et al.  Multiple sclerosis: gadolinium enhancement in MR imaging. , 1986, Radiology.

[7]  B E Kendall,et al.  Serial gadolinium enhanced magnetic resonance imaging in multiple sclerosis. , 1988, Brain : a journal of neurology.

[8]  J. Oger,et al.  Multiple sclerosis , 1988, Neurology.

[9]  B E Kendall,et al.  Breakdown of the blood-brain barrier precedes symptoms and other MRI signs of new lesions in multiple sclerosis. Pathogenetic and clinical implications. , 1990, Brain : a journal of neurology.

[10]  D Gounot,et al.  In vivo determination of multiexponential T2 relaxation in the brain of patients with multiple sclerosis. , 1991, Magnetic resonance imaging.

[11]  R I Grossman,et al.  Experimental allergic encephalomyelitis and multiple sclerosis: lesion characterization with magnetization transfer imaging. , 1992, Radiology.

[12]  Roland Martin,et al.  Using gadolinium‐enhanced magnetic resonance imaging lesions to monitor disease activity in multiple sclerosis , 1992, Annals of neurology.

[13]  J. Mazziotta,et al.  MRI‐PET Registration with Automated Algorithm , 1993, Journal of computer assisted tomography.

[14]  W. I. McDonald,et al.  Quantitative brain MRI lesion load predicts the course of clinically isolated syndromes suggestive of multiple sclerosis , 1994, Neurology.

[15]  G. Barker,et al.  Correlation of magnetization transfer ration with clinical disability in multiple sclerosis , 1994, Annals of neurology.

[16]  R H Edwards,et al.  Magnetic resonance relaxation time mapping in multiple sclerosis: normal appearing white matter and the "invisible" lesion load. , 1994, Magnetic resonance imaging.

[17]  Dewey Odhner,et al.  3DVIEWNIX: an open, transportable, multidimensional, multimodality, multiparametric imaging software system , 1994, Medical Imaging.

[18]  R R Edelman,et al.  Brain lesions in patients with multiple sclerosis: detection with echo-planar imaging. , 1995, Radiology.

[19]  R. Kikinis,et al.  The evolution of multiple sclerosis lesions on serial MR. , 1995, AJNR. American journal of neuroradiology.

[20]  R I Grossman,et al.  Microscopic disease in normal-appearing white matter on conventional MR images in patients with multiple sclerosis: assessment with magnetization-transfer measurements. , 1995, Radiology.

[21]  A. Thompson,et al.  A preliminary study into the sensitivity of disease activity detection by serial weekly magnetic resonance imaging in multiple sclerosis. , 1996, Journal of neurology, neurosurgery, and psychiatry.

[22]  R E Lenkinski,et al.  Proton MR spectroscopy and magnetization transfer ratio in multiple sclerosis: correlative findings of active versus irreversible plaque disease. , 1996, AJNR. American journal of neuroradiology.

[23]  Supun Samarasekera,et al.  Multiple sclerosis lesion quantification using fuzzy-connectedness principles , 1997, IEEE Transactions on Medical Imaging.

[24]  Hans Lassmann,et al.  Inflammatory central nervous system demyelination: Correlation of magnetic resonance imaging findings with lesion pathology , 1997, Annals of neurology.

[25]  Imaging of remyelination , 1997, Multiple sclerosis.

[26]  J K Udupa,et al.  Global volumetric estimation of disease burden in multiple sclerosis based on magnetization transfer imaging. , 1997, AJNR. American journal of neuroradiology.

[27]  S. Reingold,et al.  The role of magnetic resonance techniques in understanding and managing multiple sclerosis. , 1998, Brain : a journal of neurology.

[28]  J. Caillé,et al.  Early structural changes in acute MS lesions assessed by serial magnetization transfer studies , 1998, Neurology.

[29]  M Filippi,et al.  Magnetization transfer changes in the normal appering white matter precede the appearance of enhancing lesions in patients with multiple sclerosis , 1998, Annals of neurology.

[30]  M. Horsfield,et al.  Quantitative assessment of magnetic resonance imaging lesion load in multiple sclerosis. , 1998, Journal of neurology, neurosurgery, and psychiatry.

[31]  G J Barker,et al.  Serial magnetization transfer imaging to characterize the early evolution of new MS lesions , 1998, Neurology.

[32]  A J Thompson,et al.  MRI lesion volume measurement in multiple sclerosis and its correlation with disability: a comparison of fast fluid attenuated inversion recovery (fFLAIR) and spin echo sequences , 1998, Journal of neurology, neurosurgery, and psychiatry.

[33]  V. Dousset,et al.  Pathological correlates of magnetization transfer imaging abnormalities in animal models and humans with multiple sclerosis. , 1999, Neurology.

[34]  G S Francis,et al.  Combined magnetization transfer and proton spectroscopic imaging in the assessment of pathologic brain lesions in multiple sclerosis. , 1999, AJNR. American journal of neuroradiology.

[35]  J K Udupa,et al.  Relapsing-remitting multiple sclerosis: longitudinal analysis of MR images--lack of correlation between changes in T2 lesion volume and clinical findings. , 1999, Radiology.

[36]  P. Valk,et al.  Staging of multiple sclerosis (MS) lesions: pathology of the time frame of MS. , 2000 .

[37]  J K Udupa,et al.  Multiple sclerosis: magnetization transfer histogram analysis of segmented normal-appearing white matter. , 2000, Radiology.

[38]  L G Nyúl,et al.  Numerical tissue characterization in MS via standardization of the MR image intensity scale , 2000, Journal of magnetic resonance imaging : JMRI.

[39]  R Stollberger,et al.  A comparison of magnetization transfer ratio, magnetization transfer rate, and the native relaxation time of water protons related to relapsing-remitting multiple sclerosis. , 2000, AJNR. American journal of neuroradiology.

[40]  G. B. Pike,et al.  Multiple sclerosis: magnetization transfer MR imaging of white matter before lesion appearance on T2-weighted images. , 2000, Radiology.

[41]  J K Udupa,et al.  Glatiramer acetate (Copaxone) treatment in relapsing–remitting MS , 2000, Neurology.

[42]  A. Grüters,et al.  Molecular Pathogenesis of Neonatal Hypothyroidism , 2000, Hormone Research in Paediatrics.

[43]  B Quesson,et al.  In vivo evaluation of remyelination in rat brain by magnetization transfer imaging , 2000, Journal of the Neurological Sciences.

[44]  F Barkhof,et al.  Post-mortem MRI-guided sampling of multiple sclerosis brain lesions: increased yield of active demyelinating and (p)reactive lesions. , 2001, Brain : a journal of neurology.

[45]  L. Balcer.  Clinical Outcome Measures for Research in Multiple Sclerosis , 2001, Journal of neuro-ophthalmology : the official journal of the North American Neuro-Ophthalmology Society.

[46]  G J Barker,et al.  Investigation of MS normal-appearing brain using diffusion tensor MRI with clinical correlations , 2001, Neurology.

[47]  Jayaram K. Udupa,et al.  Multiprotocol MR Image Segmentation in Multiple Sclerosis , 2001 .

[48]  Oded Gonen,et al.  Brain metabolite profiles of T1-hypointense lesions in relapsing-remitting multiple sclerosis. , 2003, AJNR. American journal of neuroradiology.

[49]  H. Lassmann.  Neuropathology in multiple sclerosis: new concepts , 1998, Multiple Sclerosis.

[50]  C. Lucchinetti,et al.  Remyelination in multiple sclerosis , 1997, Multiple sclerosis.