MRI measures of brain injury in children with Multiple Sclerosis
Notice bibliographique
Résumé
Multiple sclerosis (MS) is thought to be an autoimmune disease that affects the central nervous system of young adults. Although an uncommon disease in children, recent research has examined the effect of this disease upon a younger demographic group. This patient population has attracted the attention of MS researchers, as it promises a better understanding of the pathophysiology of MS at its earliest stage. Magnetic resonance imaging (MRI), a sensitive tool for detecting white matter (WM) pathology, has improved the diagnosis and appreciation of the pathogenesis of MS in adults. However, little is known about its use in children. Therefore, the main objective of this thesis is to contribute and to increase knowledge in this important new area. For this purpose, specific image processing methodologies were developed, and pathology on MRI was compared between patients with adult- and pediatric-onset MS. Comparing the spatial distribution, frequency, and volume of lesions on T2-weighted (T2w) MR images among patients with pediatric- and adult-onset MS, who had similar disease duration, showed a similar total T2w lesions between the two groups. However, children exhibited a higher T2w lesion volume and frequency in the infratentorial region, particularly in the pontine region. Persistent T1-weighted (T1w) lesions, a marker of permanent tissue damage and axonal loss, were assessed to determine whether MS lesions in children are as destructive as those in adults. To obtain a fair comparison using the scans available, normalization of intensity was essential. We showed the limitations of the currently available techniques for intensity normalization, and the need for a WM independent methodology. We proposed and developed a novel WM-independent intensity normalization method for T1w images and assessed inter-scanner, between-scanner and within subject variation before and after normalization. We also calculated the sample size required for detecting recovery of T1w intensity using our methodology and the most commonly used intensity normalization method. Then we used our methodology to assess recovery of normalized T1w intensity within new lesions in children with relapsing remitting MS (RRMS) compared to adults. We found that MS lesions recover better in children, suggesting a greater reparative capacity in younger patients. We also used our intensity normalization method to perform a quantitative comparison of T1w intensity recovery in new lesions between children with MS and children with monophasic inflammatory demyelinating syndromes (monoADS). We found that new MS lesions recover more poorly than of those in children with monoADS. This may suggest that new MS lesions are more destructive than new lesions in monophasic inflammatory demyelinating diseases.
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,002 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 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 source (Gemma direct ou Codex distillé), 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 ».