The Attraction of Dry-Magnet MRI Systems

There is a world shortage of helium. The gas is used in the freezing systems of MRI machines and a lack of supply could have big implications for global healthcare. 

David Taylor, CEO, MR Solutions talks to us about their development of dry-magnet MRI systems that do not rely on helium. 

TN: Please can you tell us about your role at MR Solutions?

DT: I am the founder and CEO of MR Solutions, a UK-based developer and manufacturer of preclinical MRI systems and imaging accessories; plus spectrometers – these are the control systems within an MRI system.

I oversee an extremely talented team of scientists and engineers who have led the world in developing cryogen-free high field MRI systems (MRI systems incorporate magnets which need to be cooled to + 4 degrees Kelvin so that the magnets are superconductive to provide the tesla power to achieve super resolutions) as well as developing the first commercial, multi-modality imaging systems which incorporate into one scanner MRI, PET and or SPECT which provides researchers with even better and more useful scans.

One of my key roles in ensuring that we remain at the forefront of technology is to visit and discuss with the top researchers at universities all over the globe what they want and their vision of the future of scanning. I then go back and challenge my team to deliver a commercial product which can deliver what they have envisaged. 

This has led to researchers using our groundbreaking cryogen-free MRI systems in drug development, or when studying anatomy, to measure changes at cell level. However, we have also supplied systems for rock core analysis in the petro-chemical sector and in other industrial applications.

TN: What are the origins of MR Solutions?

DT: I had better start at the beginning and explain my keen interest in physics. As a student at Nottingham University I was part of a nuclear magnetic resonance spectroscopy (NMR) research group and had the good fortune to be present when another subgroup was carrying out the world’s first MRI experiments, led by the renowned physicist Professor Sir Peter Mansfield.

Following the completion of two physics degrees at the University of Nottingham and two years as a postdoctoral assistant studying liquid crystals by NMR at Leeds University I then went on to fill an academic role at the University of Surrey. It was there that I founded a research group developing MRI techniques and where I wrote the first published paper on molecular diffusion imaging in MRI which initiated future research and development.

In 1985, I spun out my own company from the university called SMIS (Surrey Medical Imaging Systems) which ran successfully for 15 years. SMIS was at the forefront of MRI and was responsible for a number of pioneering innovations including the world’s first PC-based MRI systems; the first human limb scanner; and some of the world’s first high-field human MRI systems.

I left SMIS in 1999 to form MR Research Systems Ltd which became MR Solutions in 2003. My focus was on the development of more sophisticated spectrometers – these are the brains of an MRI scanner which carry out all the control, data acquisition and processing functions – and the development of more compact and effective MRI scanners for preclinical research.

Our EVO spectrometers have led the field for more than 15 years and are used by manufacturers of MRI systems across the world. Today the eighth generation EVO spectrometers has recently been successfully launched bringing the number of installations up to more than 2000 sites across the world.

This very successful business provided the cash flow which was required to develop the cutting-edge technologies which now make us the world leader in preclinical MRI and multi-modality scanners.

Why is your bench top 9.4T dry magnet system better than the MRI systems we might be familiar with seeing in a hospital?

The most significant difference in our range of dry magnet systems – this includes our 3T, 4.7T, 7T and 9.4T systems – is the elimination of the liquid helium cooling system for high field superconducting MRI systems.

The resulting ultra-compact system produces state of the art scans that fit in to most laboratories where space generally is at a premium and they can be used by non-MRI specialists.

Our innovation has eliminated the requirement for the expensive and cumbersome liquid helium jacket and quench provision with a revolutionary magnet design incorporating superconducting magnet coils which are cooled by direct conduction by a readily available, off the shelf cryocooler fridge unit. This results in a very light weight magnet (weighing 350Kg which compares favourably with more than two tonnes previously) which can be housed in an ordinary laboratory with no special site requirements and no emergency exhaust system.

In addition the shield coil, which is built in to the magnet to reduce the extent of the stray magnetic field, can be optimally positioned. This results in a significant reduction of this stray magnetic field from metres to a few centimetres allowing the system to be placed next to other sensitive equipment.

TN: What scientific applications are your 9.4T systems used for?

DT: The 9.4T cryogen free system is our latest and highest magnet strength system – which provides even better resolution. The more powerful the magnet the better the resolution of the many software ‘sequences’. There are numerous sequences that enables the imaging of the appropriate type of tissue, organ, or function. These sequences are all specific to such imaging, having been tried and tested. Sequences are always being written and re-written to enable more detailed and specific targeted studies particularly as the power of the scanner increases.

The sequence switches on and off the magnetic field thus allowing the imaging software to build images of the area of interest. These can be slices on different planes and axes to allow detailed viewing of the animal’s anatomy.

The actual sequence time can be minutes or hours but typically the former, thus allowing many image acquisitions in the animal’s resting state, often up to an hour or more.

The acquired images can be examined and exactly the same study carried out at a later date to track any change. The platform is not just restricted to animals, but can also be used for rock cores (e.g. oil industry), plants, food stuffs and other porous substances which can also be imaged using this technology.

TN: How many systems do you have in labs around the world?

DT: There are in excess of 50 preclinical cryogen free MRI systems around the world. This includes installations in Australia, Taiwan, Japan, China, the Middle East, Europe and North America. Our export sales growth over the last three years has resulted in MR Solutions being awarded the Queen’s Award for Enterprise for international trade in 2017.

TN: Have your systems contributed to any life-science ‘break-throughs’? 

DT: We know that our preclinical imaging systems are involved in ground-breaking research but we are unable to elaborate on this. However, our systems are used for general imaging research, anatomical imaging, angiography, cardiovascular imaging, oncology, neurology and spectroscopy. Much of this research is still ongoing, for instance in drug development which takes many years.

TN: What are the challenges to developing MRI systems and how will MR Solutions overcome them?

DT: In order to make a high strength magnet the magnet coils need to carry high current. This can only be achieved practically using superconducting wire which must be operated at or below 4 degrees Kelvin (minus 269 centigrade). Traditionally this very low temperature was achieved by immersing the magnet coils in a bath of liquid helium. So the challenge presented to our development team was to develop a cooling system which did not require helium, but could reliably cool the entire magnet uniformly. 

The development of the cryogen free technology was carried out in collaboration with our magnet partners who have experience of building small magnets for other physics applications. Our team’s experience in MRI and their knowledge of magnet design resulted in the development of the world’s first commercial cryogen-free superconducting 3T magnet in 2010 with the higher Tesla models now available.

We had to rely on third party magnet suppliers to provide the magnets for our MRI systems. However, due to our demand for more magnets we have established our own magnet factory in Abingdon this year. This means that we can now produce our own magnets to order but also raise the quality and the magnet strength (now up to 9.4T – ‘T’ is for Tesla). 

TN: Finally, is there anything else you would like to add?

DT: Laboratories will increasingly find that there are new ways to work on much more complex projects with multi-modality systems that have the capability of conducting not only different, but enhanced imaging studies either simultaneously or separately. And the results will be far more likely to attain the approval of the regulatory authorities much sooner.

We are continuing to develop an increasingly wide range of multi-modality MRI scanners incorporating the very latest technology. This not only brings down the price but also offers a scanner that can provide a much wider range of data which can be combined to provide insight that was previously unattainable.

We believe that the MRI scanner will remain at the centre of these developments particularly with the developments in new applications, software and new reagents which considerably extend the imaging capabilities of an MRI scanner.

It is a very exciting time for preclinical scanning. We believe that the customisation of the MRI scanner and the development of specific applications will give preclinical scanners a much more important role in the understanding of disease progression and to develop more effective treatments.