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Background:Assessing the degree of myelin injury in patients with multiple sclerosis (MS) is challenging due to the lack of magnetic resonance imaging (MRI) methods specific to myelin quantity. By measuring distinct tissue parameters from a two-pool model of the magnetization transfer (MT) effect, quantitative magnetization transfer (qMT) may yield these indices. However, due to long scan times, qMT has not been translated clinically.Objectives:We aim to assess the clinical feasibility of a recently optimized selective inversion recovery (SIR) qMT and to test the hypothesis that SIR-qMT-derived metrics are informative of radiological and clinical disease-related changes in MS.Methods:A total of 18 MS patients and 9 age- and sex-matched healthy controls (HCs) underwent a 3.0 Tesla (3 T) brain MRI, including clinical scans and an optimized SIR-qMT protocol. Four subjects were re-scanned at a 2-week interval to determine inter-scan variability.Results:SIR-qMT measures differed between lesional and non-lesional tissue ( p Conclusion:SIR-qMT at 3 T is clinically feasible and predicts both radiological and clinical disease severity in MS.

The magnetization transfer ratio reflects the integrity of tissue structure, including myelination and axonal density. Mean magnetization transfer ratio fell in 18 untreated patients with multiple sclerosis both in normal appearing grey (-0.25 pu/year, p < 0.001) and white matter (-0.12 pu/year, p = 0.004). Conversely, mean magnetization transfer ratio was stable in 20 alemtuzumab-treated patients (grey matter: -0.01 pu/year, p = 0.87; white matter: -0.02 pu/year, p = 0.51). The gradient difference in grey matter was 0.25 pu/year (p < 0.001) after age-adjustment. These data suggest that in multiple sclerosis alemtuzumab protects against tissue damage in normal-appearing grey matter, perhaps by preventing new lesion formation.

“Aggressive” multiple sclerosis (MS) is still a challenging diagnosis, in spite of the relevant progresses concerning the comprehension of the disease mechanisms, especially through pathology studies and the advent of conventional magnetic resonance imaging (MRI). Some reviews have been already published on their clinical and therapeutical aspects, but no systematic review is available in literature about the neuroradiological features, using both conventional and advanced techniques. In particular, advanced MRI techniques, namely diffusion-weighted and tensor imaging, magnetization transfer imaging, and proton magnetic resonance spectroscopy, are giving new insights to find specific and appropriate radiological parameters that can help in targeting the diagnosis. We report a review of literature on the neuroradiological findings of aggressive forms of MS, focusing specifically on the role of advanced MRI techniques in the diagnostic phase and during follow-up.

Objective: Previous magnetization transfer (MT) studies in multiple sclerosis (MS) suggest a reduction of the MT ratio (MTR) precedes new lesion development. To gain further insight into pre-lesional tissue abnormalities, we investigated the time course of additional quantitative MT parameters. Methods: Serial magnetic resonance imaging (MRI), including a gadolinium-enhanced T1 scan and MT imaging by means of a FastPACE sequence, was performed on 12 patients (4 males, 8 females) with relapsing-remitting MS. Quantitative MT values including the magnetization exchange rate (kfor) and the native relaxation time (T1free) were analysed in the six months prior to the appearance of 44 enhancing lesions and in 88 control regions of persistently normal-appearing white matter (NAWM). Results: Appearance of new active lesions was preceded by a significant decrease of the MTR (F7,166=91.5; p for (F7,166=105.2; p free (F7,166=57.3; p for was the most pronounced pre-lesional change and together with the MTR was statistically significant already four months before the appearance of new lesion. The observed increase of T1free was relatively small. MT variables of reactivated lesions were always different from NAWM but showed no characteristic time course. Conclusions: Multiparametric MT measurements suggest both a reduction of macromolecular material and a focal increase of free water to occur several months before the appearance of an active lesion. Reduction of the magnetization exchange rate, which may result from primary damage to myelin, appears to be the leading event.