Changes and variability of proton density and T1 relaxation times in early multiple sclerosis: MRI markers of neuronal damage in the cerebral cortex

Abstract

• Cortical involvement in early MS is reflected in T1/PD quantitative MRI. • The changes are spatially heterogeneous. • Cortical damage goes beyond increased water content.

Assessment of cortical damage in early multiple sclerosis with quantitative T2 relaxometry

“…In addition to the utility of assessing absolute T 2 prolongation for detecting GM damage, there is evidence for spatially heterogeneous affection of tissue parameters in MS due to the global and focal inflammatory processes of the disease. This evidence derives from post mortem histological data and in vivo T 1 and proton density imaging results . On histology, cortical demyelination in MS is mainly found in spatially discontinuous patches in the cortex, while only rarely homogeneous, global subpial demyelination was detected .…”

Longitudinal quantitative MRI assessment of cortical damage in multiple sclerosis: A pilot study

“…qMRI measures have been shown to relate to individual tissue composition in vivo, where PD is primarily a surrogate for the water content . Therefore, a PD increase likely indicates a higher proportion of free water on a microstructural level caused by loss of neurons and other cells in MS . T 1 relaxation time is influenced by water content, but its increase has also been shown to reflect the proportion of other microcompartments and tissue changes such as the axonal density, the myelin content, and gliosis in studies that focused on WM .…”

“…These patients were scored on the Expanded Disability Status Scale (EDSS) before the first scan . The patient pool comprised participants who had previously been included in cross‐sectional analyses, and we also used data obtained from a previous study into white matter …”

“…Previous studies have shown the value of qMRI for assessing tissue damage in MS: A study into WM pathology has demonstrated changes in tissue parameters in accordance with inflammatory activity . In the cortex, a region of interest (ROI) analysis showed that cortical T 1 prolongation and PD increase are present in early MS, indicating cortical damage . A separate study confirmed a relationship between cortical T 1 and the degree of disability in a relapsing‐remitting MS (RRMS) patient group, covering a range of disability severity and disease duration .…”

Perilesional Hyperintensity on T1‐Weighted Images in Intra‐Axial Brain Masses other than Cavernous Malformations

“…In addition, in this study, we investigated T1‐weighted sequence that is dependent on other imaging and hardware parameters as well as observer experience. The ideal study would be a prospective study with quantitative longitudinal relaxation time measurements for more accurate T1 mapping . Additionally, lack of perilesional white matter in surgical specimen of most patients precludes histologic confirmation, but this is expected and unavoidable as neurosurgeons only resect the part of lesions necessary to control the pathology while minimizing risk for creating an unacceptable functional deficit.…”