Exploration of novel contrast agents for functional imaging using microwave tomography
Notice bibliographique
Résumé
Microwave tomography (MWT) or microwave imaging spectroscopy (MIS) has been studied as a promising low-cost portable alternative or complementary biomedical diagnostic technique for conventional soft-tissue imaging modalities for several years. The ability to quantitatively reconstruct unique, diagnostically useful properties of the tissue of interest (i.e. the permittivity and effective conductivity) at safe, non-ionizing frequency ranges without the need of a contrast agent has been among MWT's frequently quoted advantages, especially in the context of its most developed application in breast imaging. However, recent large-scale studies characterizing the ultra-wideband dielectric properties of freshly excised breast tissues have shown that the contrast between malignant breast carcinoma and normal fibroconnective/glandular tissue is inherently low (M. Lazebnik et al., Phys. Med. Biol. 52, 6093-6115, 2007), making it clear that this emerging technology could benefit from the use of exogenous contrast agents that selectively accumulate in cancerous tissues. This concession has spurred interest in the study of conventional and novel contrast agents in the field of microwave imaging, with recent publications employing microbubbles (S.C. Hagness et al., Phys. Med. Biol., 54, 641-650, 2009), single-walled carbon nanotubes (S.C. Hagness et al., IEEE Trans. BME, 57, 8, 1831-1834, 2010), and magnetic nanocomposites (O.M. Bucci et al., IEEE Trans. BME, 58, 9, 2528-2536, 2011) demonstrating encouraging results. A broad study of contrast agents, including compounds traditionally employed in nuclear medicine procedures (albeit using their radioactively-inert isotopic counterparts) and other conventional anatomical imaging modalities, is conducted to assess their feasibility for microwave imaging. The search is expanded to explore not only tumour markers, but any organic or non-organic chemical compounds whose distribution within live tissues could yield useful functional, physiological information. Examples include potassium analogues (rubidium, cesium), tracers for inflammation and rapid cell division (gallium, flurodeoxyglucose), tissue oxygenation markers (nitroxide and trityl radicals), blood pool agents (gadolinium-based complexes) and functionalized magnetic nanoparticles (iron oxide nanocrystals). Such chemical species with favourable complex permittivity measured in solution over a frequency range of interest are evaluated as potential MWT contrast agents for in vivo imaging applications based on similar criteria that govern their selection for other modalities. These criteria include chemical stability and water solubility, pharmacological half-life and method of clearance, ease of administration, cost and availability, and selectivity of the agent's biodistribution. The compound should demonstrate sufficient cellular uptake to significantly affect dielectric contrast in tissues of interest and most importantly, exhibit no biological toxicity at the concentrations required to obtain said contrast.
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 | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| 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) | 0,000 | 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 ».