Skope 2.0 – new communities, advancing together
Thursday, 18th of November 2021, GatherTown
Please contact us if you’re interested in the recording of a specific talk.
4th International Skope User Meeting
Despite the challenges posed by world events, the Skope community has seen growth and many successes. We would like to gather and celebrate the good progress from the year, and share with each other.
Come and learn about developments made in the Skope community this year by joining us at the 4th International Skope User Meeting on 18 November, 3pm (Central European Time) in GatherTown.
The theme for this event is ‘Skope 2.0 – new communities, advancing together’ which we believe reflects the addition of new user groups and labs around the world focusing on different research topics. This meeting will introduce some of those labs and their research, in addition to highlighting new results which move the community forward. The program includes:
- Featured Scientific Presentations from several Skope users
- Demonstrations of an integrated NeuroCam and Clip-on Camera Cranberry Edition
- Short educational workshops highlighting field monitoring advances and workflows
Looking forward to learning from new and continuing members of our community on how your advances move us all forward!
Measurement of RF-induced temperature rise in brain MR exams
The proton-resonance frequency shift (PRFS) method is reputed the most accurate MR thermometry (MRT) strategy available for the measurement of small temperature changes. Yet reaching a sub-degree precision necessary to measure RF-induced temperature rises in normal conditions at 7T requires field stability on the order of 0.3 Hz over tens of minutes. In this study, PRFS with field monitoring and dictionary-based motion compensation allowed dynamically measuring brain temperature increase through RF exposure with a precision of 0.05°C. Over 8 volunteers, measurements showed a maximal increase of about 0.2°C in the inner brain after 20-min scanning at the maximal SAR level allowed by the IEC (normal mode) and with a commercial head volume coil.
Dr. Caroline Le Ster
Dr. Caroline Le Ster studied bioscience engineering before her PhD at Siemens Healthcare. Her thesis was about diffusion, perfusion and relaxation quantification in bone marrow as biomarkers for myeloma and osteoporosis. She then joined NeuroSpin (CEA, France) for a postdoc where she worked on fMRI sequences at 7T with parallel transmission. She furthermore gained experience with the Skope field sensor technology to do scanner quality control, physiological noise correction and MR thermometry. She is now part of the AROMA project under the supervision of Nicolas Boulant. She has been working on a new MR thermometry with field monitoring method to measure non-invasively the temperature rise induced by RF field power deposition during MR exams and in the human brain. Measuring sufficiently small temperature rises in vivo could allow relaxing specific absorption rate constraints to provide more freedom to mitigate the RF field inhomogeneity problem at 11.7T using parallel transmission.
Integrating the Clip-on Camera into an RF coil at 7T
This talk will discuss the development of an RF coil with an integrated Skope Clip-on Camera. The coil was designed for use in a 7T head-only scanner, with cabling permanently integrated into the scanner architecture. The greatest challenge to such a RF coil was its operation within a head-only gradient coil, and therefore it being subjected to the corresponding design constraints. The transmit and receive performance was evaluated before and after the integration of field probes, while field probes were evaluated when in an optimal configuration external to the coil and after their integration. Diffusion-weighted EPI and single-shot spiral acquisitions were employed to evaluate the efficacy of correcting higher order field perturbations and the consequent effect on image quality. The effectiveness of higher-order field corrections was governed primarily by non-idealities in the gradient and shim fields of the head-only gradient coil at the probe positions; nonetheless, the field monitoring system could correct up to second-order field perturbations in single-shot spiral imaging. The long-term goal is to create a hardware and software workflow that is as invisible as possible to the technologist and end-user, to promote everyday use of the field camera.
Dr. Kyle Gilbert
Dr. Kyle Gilbert holds degrees in Biophysics (Honours B.Sc.) from the University of British Columbia and Physics (Ph.D.) from the University of Western Ontario. After completing a post-doctoral fellowship under the supervision of Dr. Ravi Menon, Kyle joined the CFMM as a Research Scientist in 2009. His current area of research focuses on the development of hardware for high-field MRI scanners. This includes the design and fabrication of transmit and receive radiofrequency arrays and their integration into the scanner architecture.
High order field monitoring for accurate, distortion- and ghosting-free high resolution ex vivo diffusion MRI at ultra-high b values
Diffusion MRI (dMRI) of the whole, intact, fixed postmortem human brain at high spatial resolution serves as a key bridging technology for 3D mapping of structural connectivity and tissue microstructure at the mesoscopic scale. Ex vivo dMRI offers superior spatial resolution compared to in vivo dMRI but comes with its own technical challenges due to the significantly reduced T2 relaxation times and decreased diffusivity incurred by tissue fixation. This is often compensated with the use of ultra-high b values and advanced EPI technique, 3D Multi-shot. The advent of stronger gradients on human MRI scanners (e.g., Connectom) has led to improved image quality and a wider range of diffusion-encoding parameters for dMRI but at the cost of more severe eddy currents that result in spatial and temporal variations in the background magnetic field, which cannot be corrected for using standard vendor-provided ghost correction solutions. In this work, we show that conventional techniques for ghosting correction fall shorts in rendering reliable diffusion MRI metrics, and high order field monitoring with a dynamic field camera can indeed reduce ghosting substantially as well as correct for geometric distortions in a single reconstruction step. We demonstrate eddy-current-based pervasive artifacts affect microstructural measures drastically, and high order field monitoring is needed to provide unbiased diffusion metrics.
Dr. Gabriel Ramos Llorden
Massachusetts General Hospital
Dr. Gabriel Ramos Llorden is currently a research fellow at Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, US. He is working on the BRAIN INITIATIVE funded project: Connectome 2.0: Developing the next generation human MRI scanner for bridging studies of the micro-, meso- and macro-connectome. His main interests are in diffusion MRI for brain mapping. In particular, he has developed novel reconstruction techniques for submillimeter resolution diffusion MRI both for in vivo and ex-vivo applications that allow us to understand the intricate nature of the human brain with reliable MRI data. Gabriel Ramos Llorden holds a PhD degree in Physics (2018) from the University of Antwerp, Belgium, and an MSc on Telecommunication Engineering (2012) from the University of Valladolid, Spain.
The Skope User Meeting will take place in GatherTown. The virtual space features separate rooms:
- Lobby with interactive screens
- Agenda – Information about the event
- Meet the Community – Short Hello’s
- Where to meet Skope – Events, Conferences, Workshops etc.
- Auditorium (Welcome Presentations, AROMA, Featured Scientific Presentations and Workshops)
press “x” to join the Zoom meeting through GatherTown
- Focus Rooms (1-6)
Feel free to walk around and engage with everybody you cross path with!
You will first be asked to create an avatar, please insert you name and organization (e.g. Yasemin Rüst – Skope).
To ensure a high quality experience, join Gather on Chrome and download the latest version of Zoom.
Feel free to reach out to Yasemin if you have any question to the upcoming Skope User Meeting.
Yasemin Rüst, Global Marketing Manager