| 1. |
- Beckers, Elise, et al.
(author)
-
Microstructural associations between locus coeruleus, cortical, and subcortical regions are modulated by astrocyte reactivity: a 7T MRI adult lifespan study
- 2024
-
In: CEREBRAL CORTEX. - 1047-3211 .- 1460-2199. ; 34:6
-
Journal article (peer-reviewed)abstract
- The locus coeruleus-norepinephrine system plays a key role in supporting brain health along the lifespan, notably through its modulatory effects on neuroinflammation. Using ultra-high field diffusion magnetic resonance imaging, we examined whether microstructural properties (neurite density index and orientation dispersion index) in the locus coeruleus were related to those in cortical and subcortical regions, and whether this was modulated by plasma glial fibrillary acidic protein levels, as a proxy of astrocyte reactivity. In our cohort of 60 healthy individuals (30 to 85 yr, 50% female), higher glial fibrillary acidic protein correlated with lower neurite density index in frontal cortical regions, the hippocampus, and the amygdala. Furthermore, under higher levels of glial fibrillary acidic protein (above similar to 150 pg/mL for cortical and similar to 145 pg/mL for subcortical regions), lower locus coeruleus orientation dispersion index was associated with lower orientation dispersion index in frontotemporal cortical regions and in subcortical regions. Interestingly, individuals with higher locus coeruleus orientation dispersion index exhibited higher orientation dispersion index in these (sub)cortical regions, despite having higher glial fibrillary acidic protein levels. Together, these results suggest that the interaction between locus coeruleus-norepinephrine cells and astrocytes can signal a detrimental or neuroprotective pathway for brain integrity and support the importance of maintaining locus coeruleus neuronal health in aging and in the prevention of age-related neurodegenerative diseases.
|
|
| 2. |
- Grande, Xenia, et al.
(author)
-
Ultra-high field imaging of the human medial temporal lobe
- 2023. - 1
-
In: Ultra-High Field Neuro MRI. - 9780323999533 - 9780323998987 ; 10, s. 259-259
-
Book chapter (other academic/artistic)abstract
- Ultra-high field (UHF) imaging provides substantial benefits for the structural and functional investigation of the human medial temporal lobe. The medial temporal lobe is a complex system of many subregions that is critically involved in many cognitive functions and vulnerable to neurodegenerative processes. Here, we first lay out the benefits of UHF imaging for visualizing anatomical features with high resolution to delineate subregions. We provide examples of structural imaging studies that critically rely on UHF imaging. Second, we point out how UHF functional imaging advances the investigation of the functional organization of the medial temporal lobe and its involvement in cognitive processes. Examples are given for how UHF imaging is used here to reveal critical mechanisms and information flow on the subregional and layer-specific levels. Finally, we highlight motion and signal dropout as challenges of structural and functional UHF and conclude with perspectives for UHF imaging in the future.
|
|
| 3. |
- Markenroth Bloch, Karin, et al.
(author)
-
Benefits, Challenges and Applications of Ultra-High Field Magnetic Resonance
- 2021. - 1
-
In: Advanced Neuro MR Techniques and Applications. - 9780128224793 - 9780128224953 ; 4, s. 533-571
-
Book chapter (peer-reviewed)abstract
- Human ultra-high field (UHF) MR at 7T and above has been on a rapid rise since the first installations in the 1990s, motivated by the opportunities created by SNR gains and contrast changes. Research efforts were for long focused mainly on technological developments to cope with the challenges posed by UHF. This has brought 7T MR neuroimaging to maturity and into an application dominated realm, further accelerated by the availability of clinically certified commercial 7T systems. This chapter aims to give an overview of UHF MR in a neuroimaging context by first providing an overview of the basic physical motivations for going to higher fields. It will then describe the challenges and limitations of working at higher field strengths, and outline some of the currently available solutions. This chapter also provides a discussion of the potentials of UHF by highlighting some of the neuro applications that benefit from UHF.
|
|
| 4. |
-
Ultra-High Field Neuro MRI
- 2023. - 1
-
Editorial collection (peer-reviewed)abstract
- Ultra-High Field Neuro MRI is a comprehensive reference and educational resource on the current state of neuroimaging at ultra-high field (UHF), with an emphasis on 7T. Sections cover the MR physics aspects of UHF, including the technical challenges and practical solutions that have enabled the rapid growth of 7T MRI. Individual chapters are dedicated to the different techniques that most strongly benefit from UHF, as well as chapters with a focus on different application areas in anatomical, functional and metabolic imaging. Finally, several chapters highlight the neurological and psychiatric applications for which 7T has shown benefits. The book is aimed at scientists who develop MR technologies and support clinical and neuroscience research, as well as users who want to benefit from UHF neuro MR techniques in their work. It also provides a comprehensive introduction to the field.
|
|
