Letter: Unforeseen Hurdles Associated With Magnetic Resonance Imaging in Patients With Deep Brain Stimulation Devices
Notice bibliographique
Résumé
To the Editor: Modern deep brain stimulation (DBS) devices are often advertized as being “whole-body conditional,” and this label is an important consideration when assessing the suitability of DBS for a given patient (eg, a patient who would likely require spinal imaging in the future). However, we found that unforeseen contradictions between DBS vendor guidelines and MRI manufacturer manuals rendered diagnostic “whole-body” (eg, spine) imaging unfeasible at our center, leading to deleterious effects on patient care. As described previously,1 the main risk of MRI on deep DBS patients is heating at the DBS lead tips. To mitigate this risk, DBS vendor guidelines typically include 2 heating-related thresholds that scans must be acquired within: most commonly (1) specific absorption rate (SAR) or, if available, (2) B1 + rms. Of the 2, SAR thresholds are extremely restrictive while the more permissive B1 + rms metric is less established and not universally available. Although these factors have been useful in preventing adverse events, they also have limited MRI for DBS patients.2 At our institution, our previous MRI (1.5T GE-Signa; software: HDxT 23.0_V021406.a) did not offer B1 + rms, and the SAR thresholds specified in DBS vendor guidelines meant that it was only practical to acquire diagnostic quality imaging of the head. Given the demand for MRI in DBS patients—1 study estimating that up to 75% of patients require MRI within 10 years of DBS surgery, the majority (62%) of whom calling for body and/or spine scans3—we performed rigorous phantom testing to ensure the safety of off-label (ie, outside SAR threshold) spinal scans on our GE machine.4 Recently, we upgraded our MRI to the one enabling B1 + rms measurements (1.5T Siemens-Magnetom; software: XA20), theoretically allowing us to leverage a more permissive heating-related threshold and acquire diagnostic scans within DBS guidelines. However, we found that the Siemens system displayed a warning prohibiting scans based on B1 rms values: “The actual B1 rms value may be much higher than the value displayed. Do not scan patients with implants based on this value.” This is in conflict with the recommendations of DBS vendor guidelines, which even acknowledge potential discrepancies between real and predicted B1 + rms: “The actual B1 + rms value may differ slightly from the predicted value… The MRI Guidelines for Medtronic …requires only that the predicted B1 + rms value for the protocol is <2.0 µT.”5 Consequently, our MRI department was unable to perform clinically practical scans for extracranial pathology (eg, for the spine) without breaching DBS vendor guidelines or MRI manufacturer recommendations. The delays caused by this impasse have compromised patient care and ultimately led us back to square 1, in which we had to reproduce our phantom safety experiments using the Siemens MRI to facilitate off-label whole-body imaging. It is important that the DBS and radiology community are aware of the contradictory guidelines set by major MRI and DBS manufacturers, which we have not previously seen described in the literature and the considerable hurdles that they can impose.
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 | 0,002 | 0,034 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,002 | 0,001 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,002 |
| Communication savante | 0,002 | 0,003 |
| Science ouverte | 0,002 | 0,001 |
| Intégrité de la recherche | 0,020 | 0,016 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,006 | 0,004 |
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 ».