A novel Virtual Reality based system for MR imaging of awake young children
Poster No:
2345
Submission Type:
Abstract Submission
Authors:
Laura Bravo Balsa1, Kun Qian1, Lucilio Cordero-Grande2,1, Molly Eddison1, Jessica Cader1, Jonathan O'Muircheartaigh1,3,4, A. Edwards1,5,3, Eva Loth4, Joseph Hajnal1, Tomoki Arichi1,3,5
Institutions:
1Centre for the Developing Brain, King's College London, London, UK, 2Universidad Politécnica de Madrid & CIBER-BBN, Madrid, Spain, 3Centre for Neurodevelopmental Disorders, King’s College London, London, UK, 4Department of Forensic and Neurodevelopmental Sciences, IoPPN, King’s College London, London, UK, 5Guy’s and St Thomas’ NHS Foundation Trust, London, UK
First Author:
Co-Author(s):
Lucilio Cordero-Grande
Universidad Politécnica de Madrid & CIBER-BBN|Centre for the Developing Brain, King's College London
Madrid, Spain|London, UK
Universidad Politécnica de Madrid & CIBER-BBN|Centre for the Developing Brain, King's College London
Madrid, Spain|London, UK
Jonathan O'Muircheartaigh
Centre for the Developing Brain, King's College London|Centre for Neurodevelopmental Disorders, King’s College London|Department of Forensic and Neurodevelopmental Sciences, IoPPN, King’s College London
London, UK|London, UK|London, UK
Centre for the Developing Brain, King's College London|Centre for Neurodevelopmental Disorders, King’s College London|Department of Forensic and Neurodevelopmental Sciences, IoPPN, King’s College London
London, UK|London, UK|London, UK
A. Edwards
Centre for the Developing Brain, King's College London|Guy’s and St Thomas’ NHS Foundation Trust|Centre for Neurodevelopmental Disorders, King’s College London
London, UK|London, UK|London, UK
Centre for the Developing Brain, King's College London|Guy’s and St Thomas’ NHS Foundation Trust|Centre for Neurodevelopmental Disorders, King’s College London
London, UK|London, UK|London, UK
Eva Loth
Department of Forensic and Neurodevelopmental Sciences, IoPPN, King’s College London
London, UK
Department of Forensic and Neurodevelopmental Sciences, IoPPN, King’s College London
London, UK
Tomoki Arichi
Centre for the Developing Brain, King's College London|Centre for Neurodevelopmental Disorders, King’s College London|Guy’s and St Thomas’ NHS Foundation Trust
London, UK|London, UK|London, UK
Centre for the Developing Brain, King's College London|Centre for Neurodevelopmental Disorders, King’s College London|Guy’s and St Thomas’ NHS Foundation Trust
London, UK|London, UK|London, UK
Introduction:
The noisy and claustrophobic MRI environment is challenging for specific populations, particularly young children who may become distressed or struggle to keep still during image acquisition. Scans are therefore often performed during sleep [1] or with sedation or anesthesia in clinical practice [2]. This limits opportunities for neuroscience research to investigate the neural correlates of emerging facets of awake behaviour and cognition, and their a/typical neurodevelopmental trajectories [3].
To overcome this, we developed a novel Virtual Reality (VR) system which immerses the child in an interactive virtual world during scanning [4]. Eye tracking and an adaptive calibration free gaze estimation algorithm that is robust to subject movement enables continuous interaction with the VR environment [5] and can quantify visual attention for fMRI analysis. To resolve residual motion related image artifact, we implement the DISORDER method [6]. Here we describe the system itself and the results of pilot studies with awake toddlers, highlighting the potential to provide new insight into this understudied but critically important period of brain development.
To overcome this, we developed a novel Virtual Reality (VR) system which immerses the child in an interactive virtual world during scanning [4]. Eye tracking and an adaptive calibration free gaze estimation algorithm that is robust to subject movement enables continuous interaction with the VR environment [5] and can quantify visual attention for fMRI analysis. To resolve residual motion related image artifact, we implement the DISORDER method [6]. Here we describe the system itself and the results of pilot studies with awake toddlers, highlighting the potential to provide new insight into this understudied but critically important period of brain development.
Methods:
The VR system consists of a light-tight 3D printed headset which mates precisely with the MR scanner head coil (figure 1a). Two MR compatible video cameras (12M-I, MRC systems) are mounted inside the headset, and a wall mounted video camera monitors the patient table position. Video content is projected onto a diffuser screen in the headset by an MR compatible projector (SV-8000 MR-Mini, Avotec Inc) placed on the examination table. Audio content is presented via noise cancelling headphones (OptoActive II, Optoacoustics Ltd).
Content was developed following a series of workshops with children and families, which highlighted the need for tailored and flexible content using familiar characters. This is possible with content development using Unity (Unity Technologies) which enables easy customization for the preferences of each child. Interaction is enabled by holding gaze on items placed around the screen which trigger actions including games, videos, or character interaction. A progressive calibration algorithm which exploits additional information from each visual fixation ensures accurate motion-robust gaze estimation [5]. To maintain congruence with sensory experience, scanner table movement and gradient noise are linked to elements in the visual experience such as a moving visual perspective or work on a construction site. Retrospective motion correction of the images is done using the DISORDER framework which uses distributed and incoherent sampling orders, enabling resilience to head motion by encoding data redundancy [6]. The system has been tested with 3 healthy children under 3 years of age, using a Philips Achieva 3T scanner and a 32ch head coil.
Content was developed following a series of workshops with children and families, which highlighted the need for tailored and flexible content using familiar characters. This is possible with content development using Unity (Unity Technologies) which enables easy customization for the preferences of each child. Interaction is enabled by holding gaze on items placed around the screen which trigger actions including games, videos, or character interaction. A progressive calibration algorithm which exploits additional information from each visual fixation ensures accurate motion-robust gaze estimation [5]. To maintain congruence with sensory experience, scanner table movement and gradient noise are linked to elements in the visual experience such as a moving visual perspective or work on a construction site. Retrospective motion correction of the images is done using the DISORDER framework which uses distributed and incoherent sampling orders, enabling resilience to head motion by encoding data redundancy [6]. The system has been tested with 3 healthy children under 3 years of age, using a Philips Achieva 3T scanner and a 32ch head coil.
Results:
2 out of 3 children successfully used the system inside the scanner bore in approximately 20-minute sessions. Children were able to immediately intuitively interact with the system, and sessions were only stopped when head movement had increased suggesting that the children had become bored. Data acquired during system use included high resolution MPRAGE images, TSE T2-weighted images, FLAIR images, and fMRI. Despite residual head movement, DISORDER reconstruction provided brain images suitable for both clinical reporting and volumetric analysis (figure 1b, c).
Conclusions:
We describe and demonstrate the effectiveness of a novel framework which combines an immersive VR experience and motion tolerant imaging methods to open new possibilities for awake MR studies in young children for both clinical and research purposes. In addition to reducing the need for non-trivial interventions like anesthesia, this can enable a new generation of MR based studies of awake brain processing underlying key cognitive and behavioural functions during a critical time for their emergence and neurodevelopment.
Lifespan Development:
Early life, Adolescence, Aging 2
Modeling and Analysis Methods:
Methods Development
Motion Correction and Preprocessing
Novel Imaging Acquisition Methods:
Anatomical MRI
BOLD fMRI 1
Keywords:
Cognition
Development
Experimental Design
FUNCTIONAL MRI
MRI
MRI PHYSICS
PEDIATRIC
Pediatric Disorders
STRUCTURAL MRI
Other - Virtual Reality
1|2Indicates the priority used for review
Provide references using author date format
[2] Lawson, G.R. (2000), 'Controversy: sedation of children for magnetic resonance imaging', Archives of disease in childhood, 82(2), 150–153.
[3] Ellis, C.T. et al. (2020), 'Re-imagining fMRI for awake behaving infants', Nature communications, 11(1), 4523.
[4] Qian, K., et al. (2021), 'An eye tracking based virtual reality system for use inside Magnetic Resonance imaging Systems', Scientific Reports, 11(1), 16301.
[5] Qian, K., et al. (2023), 'Instant Gaze (IG): an interaction driven adaptive gaze control interface', PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-3486222/v1]
[6] Cordero-Grande, L. et al., (2020), 'Motion-corrected MRI with DISORDER: Distributed and incoherent sample orders for reconstruction deblurring using encoding redundancy', Magnetic Resonance in Medicine, 84(2), 713-726.