This year you have initiated a program called AROMA (Accurate, Reliable and Optimized functional Magnetic resonance imaging) which is a collaboration between MR high-field sites to enable accurate, high-resolution fMRI at 11.7T. What is your motivation?

We all know that challenges increase as we amplify the strength of the magnetic field. Therefore, to achieve something in a reasonable time frame, a consortium by regrouping skilful members across Europe would increase drastically the firepower to tackle the fundamental challenges that we are facing to optimally exploit the 11.7T scanner. The range of problems we have to face is so broad that, to my knowledge, no single laboratory would have the capacity to face them with a comparable timeline. The EU FET-Open funding framework thus appeared as an ideal platform to launch such initiative. Working with such talented individuals and teams increases tenfold the impact of the project.

The technical challenges are manifold. What do you consider to be the most challenging ones?

The B₁ field inhomogeneity of course is a big challenge but we have acquired experience at CEA throughout the years that makes us less fearful. Of course it is going to be more challenging and difficult but we will have a good basis to start facing this problem. The SAR is expected to grow at 11.7T. One approach we consider to tackle this problem is to tame temperature, instead of SAR, in RF pulse design.

On the other hand, everything related to B₀ is an additional and very important challenge. Therefore, everything related to field fluctuations at that field strength is going to be amplified. This is going to be the next big challenge.

You have mentioned motion in an indirect way, is motion in itself also something you are tackling?

Yes, there are field changes induced by motion that spread across k-space and there is motion itself which destroys coherence of the acquired data. One implies the other. However, sometimes they require different techniques to address the one or the other. Here we plan on porting the field sensors technology developed at ETH and Skope on the Siemens platform as well as investigating other complementary methods.

What do you want to contribute to neuroscience with AROMA?

I am a physicist at heart, therefore my short to mid-term goal is to provide tools adequate to optimally leverage our unique MRI instrument and collaborate with a group of talented neuroscientists at Neurospin. By providing them with powerful exploitation methods, we want to help them deciphering how the human brain works: it goes from reading mechanisms to mathematics, and to what the singularity of the human brain is compared to other animals. Our 11.7T MRI is a machine meant for exploration. There is a bet behind it and we are not sure what we are going to discover, but we hope it will be an incredible asset to investigate the brain at a finer level of details. As history has shown us, important discoveries sometimes require the development of large instruments.

One goal is in the resolution of the functional data that you want to acquire. What is your goal in terms of resolution and do you have reasoning behind why this is your goal?

I would be more moderate now. High resolution of course is highly interesting but you can also do a lot of neuroscience at more moderate resolution and exploit instead the sensitivity boost with field strength. Sensitivity washes out very fast with resolution so that investing the potential on sensitivity instead can be worth pursuing. Literature reports that gains in speed, sensitivity and thus statistical power indeed can be quite spectacular. Some fine and subtle cognitive effects require a lot of signal-to-noise-ratio, and not necessarily high resolution data. Some examples include how we process language. People who work in that area above all want more sensitivity. Yet again, to reach optimality in the acquisitions, the fundamental physics problems must be solved.

Functional imaging will be a focus but not the only thing you will do. In what way will you bring together contrasts such as functional, anatomical or different weightings?

During this project, we will try to solve the fundamental problems with innovative solutions to lead to optimal exploitation in the long run. We will benchmark all the tools that we have at our disposal to make sure the machine is working properly and make the experimental demonstration of that. As a result, the contrasts first will be standard. Innovative work in that context will follow once the tools are setup properly.

Some technical bets based on experience and simulations were taken in the design of the 11.7T magnet. So far, we have no reason to believe that bad decisions were made as first test results are encouraging. But NMR is so sensitive that full victory cannot be claimed until the final imaging tests on human subjects are performed. Therefore, we want to demonstrate with convincing evidence that everything is working properly.

The AROMA project involves multiple MRI sites; what were the biggest challenges you were facing when organizing such a big project?

The challenge is that you want competence, skills and a happy consortium. I started slow by thinking who I would like to work with. Every time I included a new partner I had to check with everybody else if they would be on board. It required a lot of back and forth on an individual basis to make sure we all agree on the way things are shaping. It required a lot of organization, communication and exchange. Needless to say, as a result it is easier if you already know the people. Human relations are important. The skills alone are not enough.

We submitted the application three times. Each iteration required interactions and meetings to answer the referees’ criticism, and strengthen the proposal. We also hired a firm specialized in the strengthening of these kind of applications. They looked at how things should be presented and made constructive comments. Finally, we got the funding!

This is an ambitious research project with a consortium based in four countries and working on different MR platforms. How are you keeping this diverse group together and motivated?

For me, motivation was key. This is why the partners involved in this project were invited. I know them personally by already having good interactions and knew that this is the kind of research they would do anyway. The project would not distract them from their regular activities but instead it would boost them. The motivation would be a natural thing simply because this is what they typically do and are interested in. Of course it still requires meetings and interaction to make sure we participate in the same effort and share the same goal. The backbone of the motivation is to do something we love. Having affinities among members of the consortium obviously is also something important.

What is an outcome of AROMA of which you would say: This is fantastic and it was well worth every minute and every cent spent on it?

The academic goal is high resolution T₂*-weighted anatomical data at 11.7T like acquired at ETH using their motion correction scheme. Next we want to demonstrate experimentally the supra-linear gain of BOLD contrast to noise ratio.

It would be a good benchmark to convince without doubt that everything is working when it comes to the magnet, acquisition and so forth. I would consider this a technical success.

Applied neuroscience research will follow. Another, longer term, success would be if people feel the tools are attractive, efficient and easy to use. We would have managed to convince people that this is the right way to go and can benefit from the 11.7T despite all the challenges we know of.