Scan-Rescan Variation of Measures Derived from Brain Magnetization Transfer Ratio Histograms Obtained in Healthy Volunteers by Use of a Semi-interleaved Magnetization Transfer Sequence

Summary: A novel semiinterleaved gradient-echo (GE) sequence for quantitative measurement of magnetization transfer ratio (MTR) is described. With this sequence, several lines of k-space are collected for the non-MT image then several lines are collected for the MT image, thus building up the entire k-space in distinct acquisition blocks, with a good trade-off between motion-induced misregistration and degree of MT effect. The scan-rescan coefficients of variation for several MTR histogram-derived measures from 10 healthy volunteers scanned serially with this semiinterleaved sequence proved to be lower than those achieved using a conventional GE sequence. This sequence may be useful in a clinical environment to measure MTR changes over time more reliably than when acquiring the non-MT and MT images sequentially, which inevitably are affected by patient motion

Sensitivity-Encoded Diffusion Tensor Imaging of the Cervical Cord.

Summary: The aim of this study was to apply sensitivityencoding (SENSE) echo-planar imaging (EPI) to diffusion tensor MR imaging of the cervical cord, an anatomic region where MR imaging is particularly challenging. This technique was implemented with a SENSE reduction factor of 2 and used for imaging a water phantom and five healthy volunteers. Off-resonance artifacts were notably reduced compared with those of full-FOV EPI sequences. This approach to diffusion tensor MR imaging of the cervical cord is promising for future, more extensive clinical applications

Comparison of MR pulse sequences in the detection of multiple sclerosis lesions

PURPOSE: To compare the sensitivity of conventional spin-echo, fast spin-echo, fast fluid-attenuated inversion recovery (FLAIR), and turbo gradient spin-echo MR sequences in the detection of multiple sclerosis lesions. METHODS: Conventional spin-echo, fast spin-echo, fast FLAIR, and turbo gradient spin-echo sequences were performed on a 1.0-T MR imager in seven patients with clinically definite multiple sclerosis. The images in each sequence were evaluated by two raters and consensus was reached by agreement. RESULTS: In comparing conventional spin-echo with fast spin-echo sequences, five lesions were seen only by conventional spin-echo and 63 were seen only by fast spin-echo; in comparing conventional spin-echo with fast FLAIR sequences, 18 lesions were seen only by conventional spin-echo and 109 only by fast FLAIR; in comparing conventional spin-echo with turbo gradient spin-echo sequences, 51 lesions were seen only by conventional spin-echo and seven only by turbo gradient spin-echo; in comparing fast spin-echo with fast FLAIR sequences, 45 lesions were seen only by fast spin-echo and 52 only by fast FLAIR. CONCLUSION: Fast spin-echo and fast FLAIR sequences improve the sensitivity of MR imaging in the detection of multiple sclerosis lesions with reduced acquisition time as compared with conventional spin-echo sequences. These sequences should therefore be considered for serial studies in patients with multiple sclerosis. The sensitivity of turbo gradient spin-echo was inferior to the other sequences, but its reduced acquisition time could make this technique the ideal choice for patients who cannot tolerate longer examination times

Additional file 2: of Action observation training to improve motor function recovery: a systematic review

Research strategy. (DOCX 13 kb

sj-docx-1-msj-10.1177_13524585241231155 – Supplemental material for 2.5-Year changes of connectivity dynamism are relevant for physical and cognitive deterioration in multiple sclerosis

Supplemental material, sj-docx-1-msj-10.1177_13524585241231155 for 2.5-Year changes of connectivity dynamism are relevant for physical and cognitive deterioration in multiple sclerosis by Maria A Rocca, Giulia D’Amore, Paola Valsasina, Nicolò Tedone, Alessandro Meani and Massimo Filippi in Multiple Sclerosis Journal</p

Cognitive Impairment in Myotonic Dystrophy Type 1 Is Associated with White Matter Damage

<div><p>Objective</p><p>To investigate grey (GM) and white matter (WM) abnormalities and their effects on cognitive and behavioral deficits in a large, phenotypically and genotypically well-characterized cohort of classic adult (aDM1, age at onset ≥20 years) or juvenile (jDM1, age at onset <20 years) patients with myotonic dystrophy type 1 (DM1).</p><p>Methods</p><p>A case-control study including 51 DM1 patients (17 jDM1 and 34 aDM1) and 34 controls was conducted at an academic medical center. Clinical, cognitive and structural MRI evaluations were obtained. Quantitative assessments of regional GM volumes, WM hyperintensities (WMHs), and microstructural WM tract damage were performed. The association between structural brain damage and clinical and cognitive findings was assessed.</p><p>Results</p><p>DM1 patients showed a high prevalence of WMHs, severe regional GM atrophy including the key nodes of the sensorimotor and main cognitive brain networks, and WM microstructural damage of the interhemispheric, corticospinal, limbic and associative pathways. WM tract damage extends well beyond the focal WMHs. While aDM1 patients had severe patterns of GM atrophy and WM tract damage, in jDM1 patients WM abnormalities exceeded GM involvement. In DM1, WMHs and microstructural damage, but not GM atrophy, correlated with cognitive deficits.</p><p>Conclusions</p><p>WM damage, through a disconnection between GM structures, is likely to be the major contributor to cognitive impairment in DM1. Our MRI findings in aDM1 and jDM1 patients support the hypothesis of a degenerative (premature aging) origin of the GM abnormalities and of developmental changes as the principal substrates of microstructural WM alterations in DM1.</p></div

Diffusion MR Imaging in Multiple Sclerosis: Technical Aspects and Challenges.

Diffusion tensor (DT) MR imaging has frequently been applied in multiple sclerosis (MS) because of its ability to detect and quantify disease-related changes of the tissue microstructure within and outside T2-visible lesions. DT MR imaging data collection places high demands on scanner hardware and, though the acquisition and postprocessing can be relatively straightforward, numerous challenges remain in improving the reproducibility of this technique. Although there are some issues concerning image quality, echo-planar imaging is the most widely used acquisition scheme for diffusion imaging studies. Once the DT is estimated, indexes conveying the size, shape, and orientation of the DT can be calculated and further analyzed by using either histogram- or region-of-interest– based analyses. Because the orientation of the DT reflects the orientation of the axonal fibers of the brain, the pathways of the major white matter tracts can also be visualized. The DT model of diffusion, however, is not sufficient to characterize the diffusion properties of the brain when complex populations of fibers are present in a single voxel, and new ways to address this issue have been proposed. Two developments have enabled considerable improvements in the application of DT MR imaging: high magnetic field strengths and multicoil receiver arrays with parallel imaging. This review critically discusses models, acquisition, and postprocessing approaches that are currently available for DT MR imaging, as well as their limitations and possible improvements, to provide a better understanding of the strengths and weaknesses of this technique and a background for designing diffusion studies in MS

Graph showing error bars of means and standard deviations of empathy quotient (EQ) score in the three groups of subjects.

<p>See text for further details.</p

Main demographic, clinical and conventional MRI data from healthy controls and DM1 patients.

<p>Values are means ± standard deviations (range or % of subjects with pathological scores relative to cut off values) or number of subjects. P values refer to Pearson chi-square or Mann-Whitney U test (see text for further details). Abbreviations: aDM1, Myotonic dystrophy type 1 with adult onset (≥20 years); DM1, Myotonic dystrophy type 1; DSS, Daytime Sleepiness Scale; KFSS, Krupp’s Fatigue Severity Scale; HC, Healthy controls; jDM1, Myotonic dystrophy type 1 with childhood onset (<20 years); ns, not significant; MIRS, Muscular impairment rating scale; MRI, magnetic resonance imaging; WMH, white matter hyperintensity.</p

Neuropsychological and behavioural data of DM1 patients.

<p>Values are means ± standard deviations (% of subjects with abnormal test score compared with normative data of reference, see text for further details).</p>#<p>p<0.05 in aDM1 <i>vs</i> jDM1 patients (Poisson model, false-discovery rate adjusted for multiple comparisons;</p><p>*age-adjusted p values). Abbreviations: ACE-R, Addenbrooke’s Cognitive Examination–Revised; aDM1, Myotonic dystrophy type 1 with adult onset (≥20 years); BNT, Boston Naming Test; DM1, Myotonic dystrophy type 1; HDRS, Hamilton Depression Rating Scale; HARS, Hamilton Anxiety Rating Scale; jDM1, Myotonic dystrophy type 1 with early onset (<20 years); ns, not significant; RAVLT, Rey Auditory Verbal Learning test; TMT, Trials Making Test; VOT, Visual Organization Test; WAIS, Wechsler-Adult Intelligence Scale.</p