European Ultrahigh‐Field Imaging Network for Neurodegenerative Diseases (EUFIND)

Düzel, Emrah; Acosta‐Cabronero, Julio; Berron, David; Biessels, Geert Jan; Björkman–Burtscher, Isabella M.; Bottlaender, Michel; Bowtell, Richard; Buchem, Mark van; Cárdenas-Blanco, Arturo; Boumezbeur, Fawzi; Chan, Dennis; Clare, Stuart; Costagli, Mauro; Rochefort, Ludovic de; Fillmer, Ariane; Gowland, Penny; Hansson, Oskar; Hendrikse, Jeroen; Kraff, Oliver; Ladd, Mark E.; Ronen, Itamar; Petersen, Esben Thade; Rowe, James B.; Siebner, Hartwig R.; Stoecker, Tony; Straub, Sina; Tosetti, Michela; Uludağ, Kâmil; Vignaud, Alexandre; Zwanenburg, Jaco J.M.; Speck, Oliver

doi:10.1016/j.dadm.2019.04.010

Cited by 21 publications

(25 citation statements)

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“…During the fMRI experiment, participants performed a visual memory encoding paradigm with an indoor/outdoor judgment as the incidental encoding task (see Figure 1A). Compared to earlier publications of this paradigm (Assmann et al, 2020; Barman et al, 2014; Düzel et al, 2011; Schott et al, 2014), the trial timings had been adapted as part of the DELCODE protocol (Bainbridge et al, 2019; Düzel et al, 2019). Subjects viewed a series of photographs showing either an indoor or an outdoor scene, which were either novel to the participant at the time of presentation (44 indoor and 44 outdoor scenes) or were repetitions of two pre-familiarized “master” images (i.e.…”

Section: Methodsmentioning

confidence: 99%

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Bayesian model selection favors parametric over categorical fMRI subsequent memory models in young and older adults

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Richter

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Subsequent memory paradigms allow to identify neural correlates of successful encoding by separating brain responses as a function of memory performance during later retrieval. In functional magnetic resonance imaging (fMRI), the paradigm typically elicits activations of medial temporal lobe, prefrontal and parietal cortical structures in young, healthy participants. This categorical approach is, however, limited by insufficient memory performance in elderly and particularly memory-impaired individuals. A parametric modulation of encoding-related activations with memory confidence could overcome this limitation. Here, we applied cross-validated Bayesian model selection (cvBMS) for first-level fMRI models to a visual subsequent memory paradigm in young (18-35 years) and elderly (51-80 years) adults. Nested cvBMS revealed that parametric models, especially with non-linear transformations of memory confidence ratings, outperformed categorical models in explaining the fMRI signal variance during encoding. We thereby provide a framework for improving the modeling of encoding-related activations and for applying subsequent memory paradigms to memory-impaired individuals.

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Section: Methodsmentioning

confidence: 99%

“…Structural and functional MRI data were acquired on two Siemens 3T MR tomographs, (Siemens Verio; 58 young, 83 older; Siemens Skyra: 48 young, 70 older), following the exact same protocol used in the DELCODE study (Düzel et al, 2019; Jessen et al, 2018). 1…”

Section: Methodsmentioning

confidence: 99%

Bayesian model selection favors parametric over categorical fMRI subsequent memory models in young and older adults

Soch

Richter

Schütze

et al. 2020

Preprint

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“…Understanding the patterns of deposition and their association with other risk factors is a key area of clinical research, but progress has been limited by the need to scale over multi-centre trials ( Moeller et al., 2019 ). The EUFIND ( Düzel et al., 2019 ) is an example of a network focused on advancements in neurodegenerative research by running large-scale multi-centre imaging studies. Also, the UK7T network ( http://www.uk7t.org ) has recently run a multi-site study with a dementia cohort to assess feasibility in patient groups.…”

Section: Introductionmentioning

confidence: 99%

Multi-centre, multi-vendor reproducibility of 7T QSM and R2* in the human brain: Results from the UK7T study

et al. 2020

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Introduction We present the reliability of ultra-high field T 2 * MRI at 7T, as part of the UK7T Network's “Travelling Heads” study. T 2 *-weighted MRI images can be processed to produce quantitative susceptibility maps (QSM) and R 2 * maps. These reflect iron and myelin concentrations, which are altered in many pathophysiological processes. The relaxation parameters of human brain tissue are such that R 2 * mapping and QSM show particularly strong gains in contrast-to-noise ratio at ultra-high field (7T) vs clinical field strengths (1.5–3T). We aimed to determine the inter-subject and inter-site reproducibility of QSM and R 2 * mapping at 7T, in readiness for future multi-site clinical studies. Methods Ten healthy volunteers were scanned with harmonised single- and multi-echo T 2 *-weighted gradient echo pulse sequences. Participants were scanned five times at each “home” site and once at each of four other sites. The five sites had 1× Philips, 2× Siemens Magnetom, and 2× Siemens Terra scanners. QSM and R 2 * maps were computed with the Multi-Scale Dipole Inversion (MSDI) algorithm ( https://github.com/fil-physics/Publication-Code ). Results were assessed in relevant subcortical and cortical regions of interest (ROIs) defined manually or by the MNI152 standard space. Results and Discussion Mean susceptibility (χ) and R 2 * values agreed broadly with literature values in all ROIs. The inter-site within-subject standard deviation was 0.001–0.005 ppm (χ) and 0.0005–0.001 ms −1 (R 2 *). For χ this is 2.1–4.8 fold better than 3T reports, and 1.1–3.4 fold better for R 2 *. The median ICC from within- and cross-site R 2 * data was 0.98 and 0.91, respectively. Multi-echo QSM had greater variability vs single-echo QSM especially in areas with large B 0 inhomogeneity such as the inferior frontal cortex. Across sites, R 2 * values were more consistent than QSM in subcortical structures due to differences in B 0 -shimming. On a between-subject level, our measured χ and R 2 * cross-site variance is comparable to within-site variance in the literature, suggesting that it is reasonable to pool data across sites using our harmonised protocol. Conclusion The harmonized UK7T protocol and pipeline delivers on average a 3-fold improvement in the coefficient of reproducibility for QSM and R 2 * at 7T compared to previous reports of multi-site reproducibility at 3T. These protocols are ready for use i...

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“…There has been a large recent expansion of 7 Tesla MRI infrastructure, driven by the release of the first commercially available clinical (CE-marked) 7 Tesla MRI system (U. S. Food & Drug Administration, 2017), opening up the possibility of wide translation of 7 Tesla to clinical applications. Further, recent work from the UK 7T Network (Clarke et al, 2020;Rua et al, 2020), German Ultra-high Field Imaging Network (Voelker et al, 2016) and European Ultrahigh-Field Imaging Network in Neurodegenerative Diseases (Düzel et al, 2019) have started to establish protocols for harmonising 7 Tesla MRI measurements across sites and scanner models with good reproducibility, providing the framework to disseminate techniques across sites.…”

Section: Introductionmentioning

confidence: 99%

Multi-centre, multi-vendor 7 Tesla fMRI reproducibility of hand digit representation in the human somatosensory cortex

Driver¹

2021

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Whilst considerable progress has been made in using ultra-high field fMRI to study brain function at fine spatial resolution, methods are generally optimized at a single site and do not translate to studies where multiple sites are required for sufficient subject recruitment. With a recent increase in installations of human 7 T systems, there is now the opportunity to establish a framework for multi-site 7 T fMRI studies. However, an understanding of the inter-site variability of fMRI measurements is required for datasets to be combined across sites. To address this, we employ a hand digit localization task and compare across-site and within-site reproducibility of 7 T fMRI to a hand digit localization task which requires fine spatial resolution to resolve individual digit representations. As part of the UK7T Network "Travelling Heads" study, 10 participants repeated the same hand digit localization task at five sites with whole-body 7T MRI systems to provide a measure of inter-site variability. A subset of the participants (2 per site) performed repeated sessions at each site for measurement of intra-site reproducibility. Dice's overlap coefficient was used to assess reproducibility, with hand region inter-site Dice = 0.70±0.04 significantly lower than intra-site Dice = 0.76±0.06, with similar trends for the individual digit maps. Although slightly lower than intra-site reproducibility, the inter-site reproducibility results are consistent with previous single site reproducibility measurements, providing evidence that multi-site 7 T fMRI studies are feasible. These results can be used to inform sample size calculations for future multi-site somatomotor mapping studies.

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European Ultrahigh‐Field Imaging Network for Neurodegenerative Diseases (EUFIND)

Cited by 21 publications

References 63 publications

Bayesian model selection favors parametric over categorical fMRI subsequent memory models in young and older adults

Bayesian model selection favors parametric over categorical fMRI subsequent memory models in young and older adults

Multi-centre, multi-vendor reproducibility of 7T QSM and R2* in the human brain: Results from the UK7T study

Multi-centre, multi-vendor 7 Tesla fMRI reproducibility of hand digit representation in the human somatosensory cortex

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