GUEST EXPERT

THE 7T CHALLENGE

 

A TON OF WORK – OR TWENTY TONS MAYBE

Roberto Martuzzi, manager of the MRI facility of the Human Neuroscience Platform at Campus Biotech, shared with us his thoughts on the various challenges awaiting the arrival of the Siemens Healthineers MAGNETOM Terra.

Logistic challenges

Is the area dedicated to the Human Neuroscience Platform at Campus Biotech expanding in order to accommodate this new MRI scanner? Where will the 7T MRI be located?

The new scanner – a Siemens Healthineers MAGNETOM Terra – will be located next to the 3T MRI to create a single MRI environment comprising both the 3T and the 7T MRIs.

The HNP MRI facility was originally designed to host two 3T MRI scanners. Nonetheless, the new 7T scanner which requires a much larger surface than a 3T and we had to expand a little bit the area of the MRI facility for accommodating it. Fortunately, there was enough usable space around the MRI facility to allow us to expand and to properly host the 7T MRI.

MRI systems are very sensitive systems. How do you deal with interferences and electromagnetic perturbations?

MR imaging is based on electromagnetic signals at a very precise frequency – the resonance frequency of the molecule of interest – which varies linearly with the intensity of the magnetic field. In the case of proton (the most widely used molecule in MRI) the imaging frequency is around 128MHz at 3T and 300MHz at 7T. These frequencies are widely used in normal communication (e.g. radio and TV channels), and we need on one side to avoid that these communications introduce noise in our images and on the other hand to avoid that MR imaging perturbs the other ongoing communications. That is the reason for placing the MRI scanners inside a Faraday cage which electromagnetically isolates the MRI from the external environment, hence blocking the interferences from and to the MRI.

Manpower challenges

You are already managing the 3T MRI, how is this a challenge for you to integrate the 7T MRI as well? Will you hire new people or train the current staff?

The installation of this new 7T MRI is the result of a joint effort with the Center for Biomedical Imaging (CIBM) and the Radiology Department of the HUG. As such, the integration of the 7T in the current environment requires to adapt the procedures and the spaces to take into account the needs and specificities of all our partners. The staff of the MRI facility will be adequately trained to use the new scanner and our technologists will operate on both scanners. In parallel, our partners the CIBM and Siemens Healthineers will bring new research staff scientists to work on the 7T MRI, develop new techniques and make them available to the community.

The Human Neuroscience Platform MRI team at work

Is it challenging to find experienced staff with regard to Ultra High Field MRI?

Fortunately, the Lemanic region is rich in expertise in MRI, including at Ultra-High Field. The strength of this project is the partnership with the CIBM, which has a longstanding reputation of excellence in UHF imaging, and with Siemens Healthineers, our scanner manufacturer. We will join the forces to let all the researchers benefit from the full extent of possibilities that the new 7T MRI offers, and beyond.

Community challenges

How well established is the Ultra High Field MRI community in Switzerland?

In Switzerland we have a longstanding tradition of UHF imaging. The pioneers were within the CIBM where a human 7T MRI was installed already 15 years ago and through these years the CIBM researchers and users were able to generate an outstanding contribution in terms of technological development, methodological research, and neuroscience applications. Shortly after, a 7T MRI was also installed in Zurich. In more recent days, the Sitem-Insel in Bern and the Balgrist Campus in Zurich have installed the same Siemens Healthineers MAGNETOM Terra that we are currently installing at Campus Biotech.

The presence of so many UHF scanners in Switzerland has already created a vibrant community of 7T developers and users which will be enriched by the arrival of this new 7T scanner.

Various examples of MR images acquired using a Siemens Healthineers MAGNETOM Terra system (Susceptibility Weighted Imaging,  Sodium MRI, Structural MRI, Angiography). All credits to Siemens Healthineers, Erlangen, Germany

Are there misconceptions surrounding Ultra High Field MRI performances?

Ultra-High Field imaging opens new possibilities to understand the anatomy and the functions of the human brain as well as other body parts. But along with these opportunities come new issues, and new challenges arrive as well. For example, imaging artifacts and inhomogeneities are more pronounced at higher magnetic field intensity and we have to deal with them from a technological point of view – e.g., newer ways to acquire and to reconstruct the images – as well as from a signal processing point of view – new methods to process and analyze the images. The partnership with the CIBM and with Siemens Healthineers is essential to efficiently tackle these new challenges.

As a researcher used to experiment at lower fields, is it complicated to use a 7T scanner? If yes, how so and will the HNP provide help?

As previously said, there are certain differences between scanning at 3T and at 7T and the researchers need to adapt their experimental setup and analysis pipeline if they want to fully benefit of the advantages of Ultra-High Field imaging. The users will be supported not only by the HNP staff but also by the CIBM and Siemens Healthineers collaborators, which will assist with MRI technological research such as coil or sequence development. For what concerns the HNP staff, the team of the MRI facility has already extensively used 7T scanners and this previous experience will allow us to help and advise the users throughout the entire procedure, from setting up the experimental procedures, to adjusting the sequence protocols and data analyses.

A 7 TESLA SIEMENS HEALTHINEERS MAGNETOM TERRA ON CAMPUS IN 2022

 

It is now official. The Human Neuroscience Platform (HNP) at Campus Biotech will acquire an Ultra-High-Field (UHF) 7 Tesla MRI scanner in summer 2022. The new Siemens Healthineers MAGNETOM Terra system will complement the already existing 3T Prisma MRI scanner of the HNP MRI facility.
This ambitious project is the result of an exciting collaboration between the CIBM Center for Biomedical Imaging, the Geneva University Hospitals (HUG), the University of Geneva (UNIGE), the Ecole Polytechnique Fédérale de Lausanne (EPFL) and the Fondation Campus Biotech Geneva (FCBG).