Diffusional kurtosis imaging of normal-appearing white matter in multiple sclerosis: preliminary clinical experience

Yoshida, Misao; Hori, Masaaki; Yokoyama, Kazumasa; Fukunaga, Issa; Suzuki, Michitaka; Kamagata, Koji; Shimoji, Keigo; Nakanishi, Atsushi; Hattori, Nobutaka; Masutani, Yoshitaka; Aoki, Shigeki

doi:10.1007/s11604-012-0147-7

Cited by 67 publications

(46 citation statements)

References 41 publications

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“…To be mentioned here, there is another emerging technique, known as 'diffusion kurtosis imaging (DKI)', which might be even more sensitive than DTI to detect subtle microstructural changes in NAWM of LA in the near future, as indicated in relevant studies of patients with multiple sclerosis (MS). 39 A dynamic monitor of BBB permeability may also be used to evaluate the efficacy of medications aiming at endothelium or BBB protection. For example, vitamin B supplementation was found to effectively delay WMHs progression for patients with recent stroke and severe cerebral small vessel disease.…”

Section: Clinical Implications Of Multimodal Imaging Studies In Nawmmentioning

confidence: 99%

Multimodal imaging findings in normal-appearing white matter of leucoaraiosis: a review

Zhong

Lou

2016

Stroke Vasc Neurol

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Leucoaraiosis (LA), also referred to as white matter hyperintensities (WMHs), are usually seen as patchy or confluent hyperintense areas on T2-weighted or fluid-attenuated inversion recovery MRI in the elderly. It is often asymptomatic in its early stages, yet its persistent evolution to more advanced stages may lead to substantial neurological dysfunction including dementia, stroke and death. Despite its clinical significance, the pathogenic mechanisms underlying LA development are uncertain. In patients with LA, the pathophysiological changes in white matter (WM) are suggested to be continuous from WMHs to its neighbourhood ‘normal-appearing white matter (NAWM)’ on conventional MRI sequences. Multimodal imaging studies revealed that the so-called ‘NAWM’ was actually abnormal with regard to underlying haemodynamic and microstructural changes. On the basis of positron emission tomography CT, xenon-CT, perfusion MRI, etc, the cerebral blood flow of NAWM was found to be significantly reduced in patients with LA, compared with healthy controls. Meanwhile, the integrity of microstructures and blood–brain barrier in NAWM was also demonstrated to be impaired with diffusion tensor imaging and dynamic contrast-enhanced MRI studies, respectively. In addition,the integrity of NAWM correlated much stronger with cognitive performance than did WMHs load. It is reasonable to assume that the subtle injury of NAWM would be more reversible than WMHs themselves. Therefore, multimodal imaging modalities could be appropriately applied to future interventional studies targeting at early pathophysiological changes of NAWM. In this paper, we summarise current knowledge about NAWM of LA mainly acquired from multimodal imaging studies in vivo, and attempt to give options for future work.

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Section: Clinical Implications Of Multimodal Imaging Studies In Nawmmentioning

confidence: 99%

Multimodal imaging findings in normal-appearing white matter of leucoaraiosis: a review

Zhong

Lou

2016

Stroke Vasc Neurol

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“…Moreover, by combining the information from both the DT and KT, DKI has recently been shown to be useful in providing estimates of biophysical parameters, such as fibre density and intra-and extra-cellular diffusivities (Fieremans et al, 2011). All these metrics have shown promising results in many human brain studies, revealing additional clinical information relative to the standard DT-based measures (e.g., Falangola et al, 2008;Fieremans et al, 2013;Gonga et al, 2013;Helpern et al, 2011;Hui et al, 2012;Wang et al, 2011;Yoshida et al, 2013). Nevertheless, these metrics are still limited for not taking into account the complex white matter architecture of crossing or fanning fibres.…”

Section: Introductionmentioning

confidence: 99%

Exploring the 3D geometry of the diffusion kurtosis tensor—Impact on the development of robust tractography procedures and novel biomarkers

et al. 2015

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Diffusion kurtosis imaging (DKI) is a diffusion-weighted technique which overcomes limitations of the commonly used diffusion tensor imaging approach. This technique models non-Gaussian behaviour of water diffusion by the diffusion kurtosis tensor (KT), which can be used to provide indices of tissue heterogeneity and a better characterisation of the spatial architecture of tissue microstructure. In this study, the geometry of the KT is elucidated using synthetic data generated from multi-compartmental models, where diffusion heterogeneity between intra- and extra-cellular media is taken into account, as well as the sensitivity of the results to each model parameter and to synthetic noise. Furthermore, based on the assumption that the maxima of the KT are distributed perpendicularly to the direction of well-aligned fibres, a novel algorithm for estimating fibre direction directly from the KT is proposed and compared to the fibre directions extracted from DKI-based orientation distribution function (ODF) estimates previously proposed in the literature. Synthetic data results showed that, for fibres crossing at high intersection angles, direction estimates extracted directly from the KT have smaller errors than the DKI-based ODF estimation approaches (DKI-ODF). Nevertheless, the proposed method showed smaller angular resolution and lower stability to changes of the simulation parameters. On real data, tractography performed on these KT fibre estimates suggests a higher sensitivity than the DKI-based ODF in resolving lateral corpus callosum fibres reaching the pre-central cortex when diffusion acquisition is performed with five b-values. Using faster acquisition schemes, KT-based tractography did not show improved performance over the DKI-ODF procedures. Nevertheless, it is shown that direct KT fibre estimates are more adequate for computing a generalised version of radial kurtosis maps.

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“…R imaging, particularly T2-weighted imaging, is used for diagnosis and follow-up in patients with MS. 1 Advanced MR imaging modalities such as DTI, diffusional kurtosis imaging, q-space imaging, and MR spectroscopy have revealed abnormalities that were not apparent on conventional T2WI in the normalappearing white matter (NAWM) 2,3 and periplaque white matter (PWM) 4,5 in the brains of patients with MS. A recently developed quantification pulse sequence called QRAPMASTER (an acronym derived from "quantification of relaxation times and proton density by multiecho acquisition of a saturation-recovery by using turbo spin-echo readout") has enabled the rapid simultaneous quantification of R1 and R2 relaxation rates and proton density (PD) in approximately 5 minutes, and thus enabled the use of these measurements in clinical practice. 6,7 Myelin volume fraction (MVF) can also be estimated based on R1, R2, and PD measurements.…”

mentioning

confidence: 99%

Analysis of White Matter Damage in Patients with Multiple Sclerosis via a Novel In Vivo MR Method for Measuring Myelin, Axons, and G-Ratio

Hagiwara¹,

Hori²,

Yokoyama

et al. 2017

AJNR Am J Neuroradiol

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Diffusional kurtosis imaging of normal-appearing white matter in multiple sclerosis: preliminary clinical experience

Abstract: DKI may be a new sensitive indicator for detecting tissue damage in MS patients in addition to conventional diffusional evaluations, for example diffusion tensor imaging.

Cited by 67 publications

References 41 publications

Multimodal imaging findings in normal-appearing white matter of leucoaraiosis: a review

Multimodal imaging findings in normal-appearing white matter of leucoaraiosis: a review

Exploring the 3D geometry of the diffusion kurtosis tensor—Impact on the development of robust tractography procedures and novel biomarkers

Analysis of White Matter Damage in Patients with Multiple Sclerosis via a Novel In Vivo MR Method for Measuring Myelin, Axons, and G-Ratio

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