The Radiological Anatomy of the Olfactory Fossa
Notice bibliographique
Résumé
Introduction: Computed tomography (CT) is a powerful tool for delineating the anatomy of the anterior skull base and paranasal sinuses. The endoscopic sinus surgeon must be well acquainted with anatomical variation to avoid dangerous iatrogenic complications. The Keros classification is a useful system for identifying potentially dangerous surgical anatomy, but it is incomplete in its description of the olfactory fossa. The goal of this study is to further characterize the relevant anatomical features of this area, along with other parameters important for endoscopic sinus surgery. Methods: CT scans of the paranasal sinuses from a database of 30 patients with various sinonasal diagnoses were randomly selected and analyzed for multiple radioanatomic features. Patients with underlying conditions that affect the integrity of the skull base were excluded. The following features were assessed using image analysis software: olfactory fossa depth, the length of the lateral lamella and the angle at which it meets the cribriform plate, fovea ethmoidal is length and shape, ethmoid roof height and slope, and the position and course of the anterior ethmoid artery. The anterior skull base was defined as the point of exit of the anterior ethmoid artery, whereas the posterior skull base was defined as the point of the sphenoethmoidal junction. Statistical analysis was performed assessing for differences in the above parameters based on skull base position and laterality, and patient demographics. Results: The 30 scans randomly selected included 17 males and 13 females with various sinonasal inflammatory conditions. The mean olfactory fossa depth of the anterior and posterior skull base was 3.4 ± 1.1 mm and 2.4 ± 0.9 mm, respectively ( p < 0.05). The mean lateral lamella length was 3.6 ± 0.9 mm, which did not significantly vary based on patient characteristics, skull base position or laterality. The angle of the lateral lamella varied significantly by skull base position, measuring 63.1 ±17.8 degrees anteriorly, and 39.1 ±17.9 degrees posteriorly ( p < 0.05). In scans where the depth of the olfactory fossa was classified as a Keros type I, 25.3% had lateral lamella were longer than 4 mm. Furthermore, 43.7% had lateral lamellae with angles less than 45 degrees. Skull base height, measured at various points, was significantly lower in females compared with males. The angle of the skull base was 19.1 ± 9.5 degrees anteriorly and only 2.4 ± 9.1 degrees posteriorly ( p < 0.05). Most importantly, moving anteriorly, the posterior skull base sloped downward in 46.7% of patients. Conclusion: Thorough preoperative assessment of CT scans is crucial to understanding the inherent variability of skull base anatomy. The skull base surgeon must appreciate that even “safe” anatomy can still contain features such as long and acutely angled lateral lamella, which may predispose patients to iatrogenic injury. Finally, despite the commonly taught surgical pearl that the skull base slopes upward in a posterior to anterior direction, this study demonstrates that a significant portion of patients can have the opposite occurring, especially in the posterior ethmoid cavity.
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 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,002 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,002 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,001 |
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 ».