Semiquantitative 3T Brain Magnetic Resonance Imaging for Dynamic Visualization of the Glymphatic-Lymphatic Fluid Transport System in Humans
Notice bibliographique
Résumé
OBJECTIVES: Recently, a novel clearing system for interstitial solutes of the brain was described as a perivascular pathway named the glymphatic system. Furthermore, lymphatic vessels were found in the meninges to drain interstitial fluids. It is hypothesized that interstitial solutes, such as amyloid β, are firstly processed through the brain by the glymphatic system and secondly drained out of the brain by lymphatic vessels (glymphatic-lymphatic fluid transport system [GLS]). Since then, various neurological disorders, such as Alzheimer disease, have been associated with a dysfunction of the GLS. In the current study, we aimed to establish a clinical magnetic resonance imaging (MRI) study protocol for visualizing lymphatic vessels as part of the GLS in humans. More importantly, we aimed to describe the dynamic changes of a contrast agent in these lymphatic vessels over time. MATERIALS AND METHODS: Twenty volunteers with an unremarkable neurological/psychiatric history were included in this 3T MRI study. Serial MRI sequence blocks were performed at 3 predefined time points (TPs): TP 1, precontrast MRI before administration of a gadolinium-based contrast agent (GBCA); TP 2, immediately post-GBCA (early ce-MRI); and TP 3, 60 minutes post-GBCA (late ce-MRI). Each MRI block contained the following sequences obtained in the same order: whole-brain 3D T1-MPRAGE, whole-brain 3D T2-FLAIR, focused 2D T2-FLAIR, and whole-brain 3D T1-SPACE. Signal intensity (SI) in compartments of the GLS adjacent to the superior sagittal sinus, gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) was calculated by manually placed regions of interest. The time course of the signal intensities was examined by generalized linear mixed models. The data were adjusted for age, cognitive function (Montreal-Cognitive-Assessment test), and sleep quality (Pittsburgh Sleep Quality Index questionnaire). RESULTS: The GLS was best visualized in the 2D T2-FLAIR and 3D T1-SPACE sequences, enabling further SI measurement. In precontrast (TP 1), the SI within the GLS was significantly higher than in CSF and significantly lower than in GM and WM. In post-GBCA, a significant increase (TP 2) and decrease (TP 3), respectively, of the GLS SI values were noted (86.3 ± 25.2% increase and subsequent decrease by 25.4 ± 9% in the 3D T1-SPACE sequence). The SI values of CSF, GM, and WM did not change significantly between the 3 TPs. CONCLUSIONS: A clinical MRI study protocol was established for the visualization of lymphatic vessels as an important part of the GLS and therefore the brain's clearing mechanism of interstitial solutes. Furthermore, dynamic changes in the GLS were described over time, possibly reflecting the clearing function of the GLS. This might constitute the basis for evaluating the GLS function in manifold neurological pathologies in the future.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».