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Magnetization transfer in multiple sclerosis
Author(s) -
Grossman Robert I.
Publication year - 1994
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.410360722
Subject(s) - magnetization transfer , white matter , multiple sclerosis , myelin , magnetic resonance imaging , nuclear magnetic resonance , chemistry , gadolinium , pathology , intensity (physics) , nuclear medicine , medicine , central nervous system , radiology , physics , immunology , quantum mechanics , organic chemistry
Magnetization transfer (MT) is a technique that has the potential for detecting changes in myelin. The rigid macromolecular structure of myelin is the physical basis of MT. By using off‐resonance irradiation, macromolecular protons can be saturated. These protons then exchange with free‐water protons and produce a decrease in signal intensity of the free‐water protons. This can be quantitated by using a magnetization transfer ratio (MTR) of signal intensities ( M 0 ‐ M s / M 0 . M 0 represents the signal intensity without off‐resonance irradiation, and M s represents the signal intensity with off‐resonance irradiation). This method has been sensitive to changes in a spectrum of white‐matter lesions, including an edema model (EAE), and regions of apparent myelin loss in patients with multiple sclerosis (MS). Furthermore, MTRs may be abnormal in patients with normal‐appearing white matter, demonstrated by standard MR imaging. MTRs may enable subcategorization of MS lesions into lesions with low MTRs (presumed to be demyelinating lesions) and lesions with higher values (primarily edematous lesions). Another important use of MT is, in conjunction with gadolinium, to increase the number and extent of enhancing MS lesions. This can improve the detection of blood‐brain barrier abnormalities in patients with MS.