The pathological substrates of MRI abnormalities in NAWM vary according to the distance from the focal lesions of the MW. Close to WM lesions, axonal pathology and microglial activation may explain subtle changes in MRI. Far from lesions, microglial activation associated with proximity to cortical lesions could underlie MRI abnormalities. This is a preview of the subscription content, which you can access through your institution.
The price does not include VAT (EE). UU) Tax calculation will be finalized during payment. School of Biology and Biochemistry, Centre for Medical Biology, Queen's University of Belfast, Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK,,,, GB School of Biomedical Sciences, Ulster University, Ulster, Northern Ireland, UK,,,,, GB Provided by the Springer Nature ShareEdit content sharing initiative. The production of maps using DTI that show the main direction of voxel-by-voxel diffusion makes it possible to trace the path of white matter tracts through the brain, known as tractography.
This novel technique holds promise for research into white matter pathology in MS and other disorders. Proton magnetic resonance spectroscopy (MRS) allows the in vivo investigation of metabolic alterations associated with brain pathology and provides a quantitative method for investigating abnormalities in normal-appearing white matter. At longer magnetic resonance imaging times, N-acetyl-aspartate (a neuroaxonal marker), creatine and phosphocreatine and choline-containing compounds can be quantified, while at shorter echo times, additional metabolite peaks can be observed in myo-inositol (a potential marker of glial cells), glutamate and glutamine, and mobile lipids. The clinical importance of these NAWM abnormalities is subject to debate, but there is a strong correlation with the degree and progression of the disability.
The use of three pairwise differences, including general NAWM, made it possible to characterize the abnormalities in both the pre-injury and the contralateral NAWM. This study was conducted to evaluate normal-appearing white matter abnormalities in areas of the brain where multiple sclerosis lesions later form, and to investigate the spatial distribution of normal-appearing white matter abnormalities in people with multiple sclerosis. Because nMtr in NAWM varies spatially across the brain (but symmetrically along the midline), pre-injury versus contralateral comparison is used to control for this spatial variability and to quantify pre-injury abnormalities that are associated with a new specific episode of T2 injury. Diffusively abnormal white matter (DAWM) is a common feature in progressive multiple sclerosis and appears to reflect a separate pathological process.
It is almost certain that cases that were previously considered to be carriers of Schilder's disease had demyelination of the subsequent hemispheric white matter caused by multiple sclerosis or adrenoleukodystrophy. MRI is an established tool for diagnosing multiple sclerosis and monitoring disease activity, and is a validated outcome measure used in clinical trials for multiple sclerosis. The comparison between magnetic resonance imaging and histopathology was successful in almost all cases; only 8% of the 630 measurements had to be excluded from further analysis. Representative cross-sectional image of a dendrite with mitochondria in post-mortem gray matter brain tissue with scanning transmission.
Background Diffuse white matter (WM) abnormalities, i.e., the so-called diffusely abnormal WM (DAWM), as seen in magnetic resonance imaging (MRI), may contribute to the development of clinical disability in multiple sclerosis (MS). Romanelli E, Merkler D, Mezydlo A et al. (201) Myelinosome formation represents an early stage of oligodendrocyte damage in multiple sclerosis and its animal model. In vivo studies have demonstrated that hypointense T1 lesions (“black holes”) have a lower MTR than isointense T1 lesions, supporting the idea that these injuries occur as a result of destructive pathology.
Once the FLAIR image is segmented into normal-looking white matter and hyperintense lesions in T2 (D), the corresponding MTR image (B) is masked (E) and the remaining voxels that are inside the normal-looking white matter and have MTR values in the range of 90 to 95% of the NAWM mean are identified as candidate SA-WM ROIs (F). To explain this dissociation, it was suggested that factors other than focal WM lesions on magnetic resonance imaging could contribute to the development of disability, that is, invisible pathological abnormalities in so-called normal-appearing white matter (NAWM) and normal-appearing gray matter. .