Validating the sensitivity of inhomogeneous magnetization transfer (ihMT) MRI to myelin with fluorescence microscopy

Duhamel, Guillaume; Prevost, Valentin H.; Cayre, Myriam; Hertanu, Andreea; Mchinda, Samira; Carvalho, Victor; Varma, Gopal; Durbec, Pascale; Alsop, David C.; Girard, Olivier

doi:10.1016/j.neuroimage.2019.05.061

Cited by 53 publications

(96 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The simplest MT measure, MT ratio (MTR), incorporates non-myelin contributions in the final measurement. Recent acquisition variations include computing MTR from acquisitions with ultra-short echo times ( Du et al, 2009 ; Guglielmetti et al, 2020 ; Wei et al, 2018 ) or relying on inhomogeneous MT ( Duhamel et al, 2019 ; Varma et al, 2015 ). More complex experiments, for example quantitative MT, are based on fitting two compartments to the data, the free water and the macromolecular compartments, or pools.…”

Section: Discussionmentioning

confidence: 99%

An interactive meta-analysis of MRI biomarkers of myelin

Mancini

Karakuzu

Cohen‐Adad

et al. 2020

eLife

123

View full text Add to dashboard Cite

Several MRI measures have been proposed as in vivo biomarkers of myelin, each with applications ranging from plasticity to pathology. Despite the availability of these myelin-sensitive modalities, specificity and sensitivity have been a matter of discussion. Debate about which MRI measure is the most suitable for quantifying myelin is still ongoing. In this study, we performed a systematic review of published quantitative validation studies to clarify how different these measures are when compared to the underlying histology. We analysed the results from 43 studies applying meta-analysis tools, controlling for study sample size and using interactive visualization (https://neurolibre.github.io/myelin-meta-analysis). We report the overall estimates and the prediction intervals for the coefficient of determination and find that MT and relaxometry-based measures exhibit the highest correlations with myelin content. We also show which measures are, and which measures are not statistically different regarding their relationship with histology.

show abstract

Section: Discussionmentioning

confidence: 99%

An interactive meta-analysis of MRI biomarkers of myelin

Mancini

Karakuzu

Cohen‐Adad

et al. 2020

eLife

123

View full text Add to dashboard Cite

show abstract

“…The simplest MT measure, MT ratio (MTR), incorporates non-myelin contributions in the final measurement. Recent acquisition variations include computing MTR from acquisitions with ultra-short echo times (Du, Takahashi, Bydder, Chung, & Bydder, 2009; Guglielmetti et al, 2020; Wei et al, 2018) or relying on inhomogeneous MT (Duhamel et al, 2019; Varma, Duhamel, de Bazelaire, & Alsop, 2015). More complex experiments, e.g.…”

Section: Discussionmentioning

confidence: 99%

An interactive meta-analysis of MRI biomarkers of myelin

Mancini

Karakuzu

Cohen‐Adad

et al. 2020

Preprint

View full text Add to dashboard Cite

Several MRI measures have been proposed as in vivo biomarkers of myelin content, each with a concrete application ranging from plasticity to pathology. Despite the broad availability of these myelin-sensitive MRI modalities, specificity and sensitivity have been a matter of discussion. Debate about which MRI measure is the most suitable one for quantifying myelin is still ongoing. In this study, we performed a systematic review of published quantitative validation studies, and used meta-analysis tools to clarify how different these measures are when compared to the underlying histology, controlling for the study sample size and using interactive visualization tools. A first qualitative selection of 58 studies proposed 35 different measures to characterize myelin content. However, a quantitative analysis showed that most of these measures have a limited coefficient of determination and provide little information to inform future studies, because of the large prediction intervals and high heterogeneity. These results indicate that most measures are statistically equivalent regarding their relationship with histology and that future work should take inter-study variability into consideration.

show abstract

“…These configurations provided a strong sensitivity enhancement and were called boosted ihMT sequences. Duhamel et al in [26] combined boosted ihMT sequences with various T 1D filtering strengths and observed signal variations in brain tissue that were not consistent with the theory if a single T 1D component was used to describe myelinated tissues, hence suggesting the existence of multiple T 1D components in myelin. An alternative view of the T 1D distribution can be obtained with Jeener-Broekaert measurements [29], which is one of the standard NMR pulse sequences to measure T 1D .…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, other biological tissues or samples, such as muscle or agarose gels, have shown much shorter dipolar relaxation times (⇠1-3 ms). Long T 1D s in myelinated tissues most likely explain the selective contrast of ihMT images for white matter [22][23][24][25] and its high specificity for myelin [26].…”

Section: Introductionmentioning

confidence: 99%

MRI assessment of multiple dipolar relaxation time (T1D) components in biological tissues interpreted with a generalized inhomogeneous magnetization transfer (ihMT) model

Carvalho

Hertanu

Grélard

et al. 2020

Journal of Magnetic Resonance

View full text Add to dashboard Cite

T 1D , the relaxation time of dipolar order, is sensitive to slow motional processes. Thus T 1D is a probe for membrane dynamics and organization that could be used to characterize myelin, the lipid-rich membrane of axonal fibers. A mono-component T 1D model associated with a modified ihMT sequence was previously proposed for in vivo evaluation of T 1D with MRI. However, experiments have suggested that myelinated tissues exhibit multiple T 1D components probably due to a heterogeneous molecular mobility. A bi-component T 1D model is proposed and implemented. ihMT images of ex-vivo, fixed rat spinal cord were acquired with multiple frequency alternation rate. Fits to data yielded two T 1D s of about 500 µs and 10 ms. The proposed model seems to further explore the complexity of myelin organization compared to the previously reported mono-component T 1D model.

show abstract

Validating the sensitivity of inhomogeneous magnetization transfer (ihMT) MRI to myelin with fluorescence microscopy

Cited by 53 publications

References 37 publications

An interactive meta-analysis of MRI biomarkers of myelin

An interactive meta-analysis of MRI biomarkers of myelin

An interactive meta-analysis of MRI biomarkers of myelin

MRI assessment of multiple dipolar relaxation time (T1D) components in biological tissues interpreted with a generalized inhomogeneous magnetization transfer (ihMT) model

Contact Info

Product

Resources

About