A source of artefact during general anaesthesia for magnetic resonance imaging

Anaesthesia ◽  
1993 ◽  
Vol 48 (7) ◽  
pp. 643-643 ◽  
Author(s):  
S. Crofts ◽  
A. Campbell
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
General Anaesthesia ◽  
Resonance Imaging

scholarly journals Neuroplasticity induced by general anaesthesia: study protocol for a randomised cross-over clinical trial exploring the effects of sevoflurane and propofol on the brain – A 3-T magnetic resonance imaging study of healthy volunteers

Trials ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Signe Sloth Madsen ◽  
Kirsten Møller ◽  
Karsten Skovgaard Olsen ◽  
Mark Bitsch Vestergaard ◽  
Ulrich Lindberg ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Clinical Trial ◽  
Cognitive Function ◽  
Magnetic Resonance ◽  
Healthy Volunteers ◽  
General Anaesthesia ◽  
Well Being ◽  
Resonance Imaging ◽  
Link Type ◽  
The Brain

Abstract Background Although used extensively worldwide, the effects of general anaesthesia on the human brain remain largely elusive. Moreover, general anaesthesia may contribute to serious conditions or adverse events such as postoperative cognitive dysfunction and delirium. To understand the basic mechanisms of general anaesthesia, this project aims to study and compare possible de novo neuroplastic changes induced by two commonly used types of general anaesthesia, i.e. inhalation anaesthesia by sevoflurane and intravenously administered anaesthesia by propofol. In addition, we wish to to explore possible associations between neuroplastic changes, neuropsychological adverse effects and subjective changes in fatigue and well-being. Methods This is a randomised, participant- and assessor-blinded, cross-over clinical trial. Thirty healthy volunteers (male:female ratio 1:1) will be randomised to general anaesthesia by either sevoflurane or propofol. Multimodal magnetic resonance imaging (MRI) of the brain will be performed before and after general anaesthesia and repeated after 1 and 8 days. Each magnetic resonance imaging session will be accompanied by cognitive testing and questionnaires on fatigue and well-being. After a wash-out period of 4 weeks, the volunteers will receive the other type of anaesthetic (sevoflurane or propofol), followed by the same series of tests. Primary outcomes: changes in T1-weighted 3D anatomy and diffusion tensor imaging. Secondary outcomes: changes in resting-state functional magnetic resonance imaging, fatigue, well-being, cognitive function, correlations between magnetic resonance imaging findings and the clinical outcomes (questionnaires and cognitive function). Exploratory outcomes: changes in cerebral perfusion and oxygen metabolism, lactate, and response to visual stimuli. Discussion To the best of our knowledge, this is the most extensive and advanced series of studies with head-to-head comparison of two widely used methods for general anaesthesia. Recruitment was initiated in September 2019. Trial registration Approved by the Research Ethics Committee in the Capital Region of Denmark, ref. H-18028925 (6 September 2018). EudraCT and Danish Medicines Agency: 2018-001252-35 (23 March 2018). www.clinicaltrials.gov, ID: NCT04125121. Retrospectively registered on 10 October 2019.

scholarly journals Exposure to surgery under general anaesthesia and brain magnetic resonance imaging changes in older adults

2019 ◽  
Vol 123 (6) ◽  
pp. 808-817 ◽  
Author(s):  
Juraj Sprung ◽  
S. Chandralekha Kruthiventi ◽  
David O. Warner ◽  
David S. Knopman ◽  
Ronald C. Petersen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Older Adults ◽  
Magnetic Resonance ◽  
General Anaesthesia ◽  
Brain Magnetic Resonance Imaging ◽  
Resonance Imaging

Asymptomatic oropharyngeal lipoma complicating intubation

2005 ◽  
Vol 119 (6) ◽  
pp. 483-485 ◽  
Author(s):  
J Rimmer ◽  
A Singh ◽  
C Irving ◽  
D J Archer ◽  
P Rhys Evans
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Airway Obstruction ◽  
General Anaesthesia ◽  
Supraglottic Airway ◽  
Resonance Imaging ◽  
Rare Tumours ◽  
Magnetic Resonance Imaging Mri ◽  
Anaesthetic Assessment

Oropharyngeal lipomas are rare tumours. We present the case of a young man with an asymptomatic lipoma almost completely occluding his supraglottic airway, found on magnetic resonance imaging (MRI) for a separate oral cavity lesion. Pre-operative anaesthetic assessment was undertaken because of the risk of airway obstruction at induction of general anaesthesia. We discuss the awake fibre-optic technique used for induction, as well as the treatment and follow-up of these tumours. This case highlights the need for formal anaesthetic assessment, in such cases, to avoid total airway obstruction at induction of general anaesthesia. It also emphasizes the extent of supraglottic obstruction that can be present without giving rise to any symptoms.

scholarly journals Characterisation of children's head motion for Magnetic Resonance Imaging with and without general anaesthesia

2021 ◽  
Author(s):  
Hannah Eichhorn ◽  
Andreea-Veronica Vascan ◽  
Martin Nørgaard ◽  
Andreas Høyby Ellegaard ◽  
Jakob Slipsager ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
General Anaesthesia ◽  
Clinical Setting ◽  
Structural Mri ◽  
Head Motion ◽  
Resonance Imaging ◽  
Motion Patterns ◽  
Motion Data ◽  
Patient Groups

Head motion is one of the major reasons for artefacts in Magnetic Resonance Imaging (MRI), which is especially challenging for children who are often intimidated by the dimensions of the MR scanner. In order to optimise the MRI acquisition for children in the clinical setting, insights into children's motion patterns are essential. In this work, we analyse motion data from 61 pediatric patients. We compare structural MRI data of children imaged with and without general anaesthesia (GA), all scanned using the same hybrid PET/MR scanner. We analyse several metrics of motion based on the displacement relative to a reference, decompose the transformation matrix into translation and rotation, as well as investigate how different regions in the brain are affected by motion. Head motion for children without GA was significantly higher (mean displacement of $2.19 \pm 0.93$ mm (median $\pm$ standard deviation) during $41.7 \pm 7.5$ min scans); however, even anaesthetised children showed substantial residual head motion (mean displacement of $1.12 \pm 0.35$ mm). For both patient groups translation along the z-axis (along the scanner bore) was significantly larger in absolute terms (GA / no GA: $0.87 \pm 0.29$ mm / $0.92 \pm 0.49$ mm) compared to the other directions. Considering directionality, both patient groups were moving in negative z-direction and thus, out of the scanner. The awake children additionally showed significantly more nodding rotation ($0.33 \pm 0.20~^{\circ}$). Consequently, in future studies as well as in the clinical setting, these predominant types of motion need to be taken into consideration to limit artefacts and reduce re-scans due to poor image quality.

Anaesthetic management of a patient undergoing magnetic resonance imaging with suspected intracranial disease

2021 ◽  
Vol 12 (6) ◽  
pp. 291-295
Author(s):  
Amy Dutton
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
General Anaesthesia ◽  
Anaesthetic Management ◽  
Resonance Imaging ◽  
Severity Of Disease ◽  
Veterinary Profession ◽  
Intracranial Disease ◽  
Future Practice

Seizing patients with suspected intracranial disease are relatively common within the veterinary profession. Veterinary nurses will be familiar with some of the most common challenges these patients present while hospitalised, however to determine the cause and severity of disease, general anaesthesia is often required. This article will discuss some of the specific considerations during the peri-anaesthetic period of a seizing patient undergoing magnetic resonance imaging, including recommendations for future practice.

scholarly journals Assessment of Upper Airway Anatomy in Awake, Sedated and Anaesthetised Patients Using Magnetic Resonance Imaging

1994 ◽  
Vol 22 (2) ◽  
pp. 165-169 ◽  
Author(s):  
G. D. Shorten ◽  
N. J. Opie ◽  
P. Graziotti ◽  
I. Morris ◽  
M. Khangure
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
General Anaesthesia ◽  
Soft Palate ◽  
Upper Airway ◽  
Posterior Pharyngeal Wall ◽  
Resonance Imaging ◽  
Pharyngeal Wall ◽  
Airway Anatomy ◽  
Clinically Significant

Magnetic Resonance Imaging was used to quantify the effects of 1. sedation and 2. general anaesthesia with a laryngeal mask airway (LMA) in place on the minimum antero-posterior (A-P) diameters of the naso-, oro- and hypopharynx and on the angle of the epiglottis relative to the adjacent posterior pharyngeal wall. Median saggital T1-weighted images of the pharynx were obtained in 46 patients (16 awake, 14 sedated, 16 under general anaesthesia). In sedated patients, the A-P diameters of the pharynx were less than in awake patients, in particular at the levels of the epiglottis and soft palate. General anaesthesia and placement of a LMA was also associated with a reduced A-P diameter at the level of the soft palate, but with increased diameters at the levels of the tongue and epiglottis. Placement of a LMA caused abnormal downfolding of the epiglottis in most cases but this did not cause clinically significant airway obstruction.

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