The effect of an inconsistent breathing amplitude on the relationship between an external marker and internal lung deformation in a porcine model
Notice bibliographique
Résumé
PURPOSE: Investigate the relationship between the motion of the Varian Real-time Position Management (RPM) device and the internal motion of a pig during induced inconsistencies in the amplitude of breathing. METHODS: Twelve studies were performed on four ventilated female Landrace cross pigs using a GE Healthcare, Discovery CT 750 HD scanner. In each study, a 4.0 cm section (64 slices) of the pig's lungs was repeatedly scanned 20 times using cine mode, each time lasting more than one breathing cycle. During these cine scans, a Varian RPM device was used to collect respiratory amplitudes and the ventilator air return tube was periodically crimped to induce inconsistent breathing amplitudes. Each breathing cycle and its associated cine scan were categorized as either consistent or inconsistent, based on thresholds of the minimum expiration and maximum inspiration amplitudes. From the group of consistent amplitude cine scans in a study, a reference scan was chosen. The effect of inconsistent breathing amplitudes on the relationship between the motion of the RPM marker and the motion within three regions of interest (in each lung and the chest wall) was investigated with two methods: (1) A 4D-CT sorting algorithm based on RPM amplitude was used to sort volumes into 4D-CT phase bins. Within each phase bin, the nonlinear deformation of volumes collected during consistent and inconsistent breathing amplitude was calculated with respect to the reference volume. The magnitude of the deformations (in mm) were compared to determine if inconsistent breathing amplitude caused greater deformations. (2) Nonlinear deformations between each CT volume from a cine scan and the maximum expiration volume of the reference scan were calculated. Regression analyses between the nonlinear deformations within three regions of interest (in each lung and the chest wall) and the RPM amplitudes were performed to test the effect of inconsistent breathing amplitudes on the linearity of the relationship between the 3D motion of internal anatomy and the 1D motion of the RPM external marker. RESULTS: (1) Inconsistent versus consistent breathing amplitudes caused a significant increase in deformation relative to the reference scan within the left lung (1.40 +/- 0.42 versus 1.29 +/- 0.36 mm, p < 0.05). (2) One-to-one correspondences between motions of internal anatomies and motion of the RPM external marker did not exist. The regression lines between the two types of motions did not yield an identity relationship (unity slope and zero intercept). Inconsistent breathing produced significantly different regression lines than consistent breathing in ten of the 12 studies within a left lung region of interest. CONCLUSIONS: The results of these two studies indicate that inconsistency in the amplitude of breathing disrupted the correspondence between the motion of the external marker and internal anatomies. As a consequence, radiation therapy of tumors embedded in lung tissue may be prone to significant errors if inconsistent breathing amplitudes occur during treatment.
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 | 0,001 | 0,002 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,001 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| 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 ».