Cerebral oxygen delivery in newborns with congenital heart disease by phase contrast MRI
Notice bibliographique
Résumé
Congenital heart disease (CHD) is associated with in utero brain dysmaturation and abnormal cerebral vasculature [ 1 , 2 ]. Phase contrast (PC) MRI allows non-invasive quantification of cerebral blood flow (CBF) and, combined with arterial oxygen saturation (SaO 2 ) and haemoglobin (Hgb) concentration, can measure cerebral oxygen delivery (CDO 2 ). We hypothesized that CDO 2 would be lower in newborns with CHD than normals. We measured CBF and brain volume (BV) in 32 unsedated newborns (21 normals and 11 CHD) as part of an IRB approved study using a 1.5T Siemens Avanto MRI. CBF was measured according to a previously published technique using a single PC acquisition prescribed perpendicular to both internal carotid arteries (ICA) and basilar artery (BA) at the clivus level [ 3 ]. We also measured flows in the vertebral arteries (VA), common carotid arteries (CCA) and internal jugular veins (IJV) using a PC acquisition through the neck. Flows were quantified and indexed to BV calculated from a high resolution 3D T2W FSE acquisition. SaO 2 and Hgb concentrations were measured using conventional blood gases in order to calculate: CDO 2 =SaO 2 ×[Hgb]×1.36×CBF [ 4 ]. We compared net and indexed CBF and CDO 2 in the two groups with an unpaired t -test with Welch's correction (Table 1 ). An analysis of CHD subgroups was also performed. The relationship between CBF and gestational age (GA) and agreement between BA vs VA flow sum was examined using Pearson's R. Subjects were scanned at a mean corrected GA of 40 weeks. MRI was performed prior to cardiac surgery in all CHD subjects. The two groups had no difference in GA (p=0.07). There were trends towards lower mean net and indexed CBF in CHD newborns compared with controls (control net CBF 138±14 vs CHD 118±10 ml/min (p=0.26), control indexed CBF 0.341±0.027 vs CHD 0.321±0.020 ml/min/ml BV (p=0.56)) (Table 1 , Figure 1a,b ). A similar trend in mean net and indexed CDO 2 was observed in CHD newborns compared with controls (control net CDO 2 2749±284 vs CHD 2191±159 ml O2 /min (p=0.1), control indexed CDO 2 6.81±0.54 vs CHD 5.99±0.31 ml O2 /min/ml BV (p=0.19)) (Figure 1c,d ). In keeping with one previous study (3), CBF increased with GA (r=0.7, p=<0.0001). The VA and BA flows were highly correlated (r=0.8, p=0.0002), indicating good accuracy of the PC assessment of CBF. There were no significant differences in measured parameters between subgroups of CHD. CHD vs control comparisons of parameters plotted against corrected gestational age measured in weeks. a) Net cerebral blood flow (ml/min) vs gestational age; b) Indexed cerebral blood flow to pre-operative brain volume (ml/min/ml BV ) vs gestational age; c) Net cerebral oxygen delivery (ml O2 /min) vs gestational age; d) Indexed cerebral oxygen delivery to pre-operative brain volume (ml O2 /min/ml BV ) vs gestational age. There is a trend in each parameter towards decreased values in CHD subjects compared to control. Although the differences between CBF and CDO 2 in this small sample of subjects were not statistically significant, there was a clear trend towards lower values for both parameters in CHD subjects. We propose that with a larger sample size, these differences will be significant, in keeping with a demonstrable relationship between cerebral oxygenation and brain maturation in CHD fetuses and newborns.
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 | 0,001 | 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 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 ».