by Farnaz Ghadaki
Using two novel Canadian technologies, a team of Canadian researchers
plan to develop a compact magnetic resonance imager
(MRI) which is much cheaper
and lighter than conventional MRIs.
This new MRI will have a
plethora of applications, both on Earth and in space.
|Full size compact MRI mockup. Images c/o Gordon Sarty, University of Saskatchewan.|
A full-size mock up of the new MRI was showcased in September at the annual conference of the American Institute of Aeronautics and Astronautics
(AIAA) but the technology has also been featured in a number of recent publications including TechNewsDaily
A few weeks ago, Gordon Sarty, Professor and Acting Chair of Biomedical Engineering at the University of Saskatchewan
, presented his team’s compact MRI technology at the 63rd Annual International Astronautical Congress
(IAC), in Naples, Italy. Sarty’s presentation highlighted the needs addressed by this compact MRI, as well as its weight and cost benefits, the novel technologies utilized plus various Earth and space applications.
|Preliminary concept of the whole body MRI as it would appear inside an ISPR. Image c/o Andrew Bell, COM DEV Canada.|
In spaceflight, there is currently very limited amount of on-orbit physiological data available. Thus, a compact MRI suitable for the International Space Station
(ISS) would be valuable in improving human health in space, as for example by enabling detailed studies of bone and muscles as well as the effects of space radiation. And on Earth, traditional MRIs are expensive and scarce resource, giving rise for a need for a smaller and cheaper solution. The compact MRI proposed by Sarty and his team addresses all these needs in a portable, robust and maintenance-free form-factor.
The Weight and Cost Benefits:
The compact MRI would come in two models: whole body sized, and extremity sized. The whole body version would be roughly 750 kg (far less than the 10 ton or more weight of conventional MRIs), and meet the volume and mass limitations of the international standard payload rack
(ISPR), which has been adopted by ISS participants in order to provide for a common set of interfaces for ISS equipment. The extremity version would be around 50 kg, and within the mass budget of the Canadian Space Agency
(CSA) for ISS experiments.
The compact MRI would be maintenance-free, translating to cost savings of $300,000 per year over a conventional MRI, and would have one tenth of initial cost of current large MRIs ($200K vs. $2M for whole body MRI). The extremity MRI would cost considerably less, at roughly $50K. Sarty and his team estimate that the number of compact MRIs could eventually end up outnumbering traditional MRIs by a factor of ten.
According to Sarty, "a Canadian MRI on the space station would be an excellent compliment to other initiatives that the CSA is now taking to establish Canada as a world-leader in advanced crew medical systems for space exploration
|Halback permanent magnet geometry. Image c/o Gordon Sarty University of Saskatchewan.|
The Novel Technologies:
The compact MRI is based on three technological innovations, with the first two being Canadian:
Earth and Space Applications:
- A radio frequency (RF) image encoding system called the TRansmit Array Spatial Encoding (TRASE), which eliminates the need for noisy, heavy, and power-consuming magnetic gradient field coils. TRASE was developed at the National Research Council of Canada, Institute for Biodiagnostics (NRC-IBD) by co-inventors Jonathan Sharp and Scott King.
- A Halbach permanent magnet, which replaces the traditional, large, heavy, and dangerous superconducting magnets. The Halbach magnet is a joint development of MRI-Tech, Canada Inc. and NRC-IBD.
- Miniaturization of RF electronics which eliminates the need for a separate rack of electronics.
The compact MRI addresses a variety of healthcare problems on Earth, the major one being making MRI diagnostic technology available anywhere globally (e.g. rural areas, remote areas, developing countries and war zones), and for variety of applications (e.g. military, ground ambulance, air ambulance, humanitarian relief, emergency room). Compact MRIs also serve as a safe and affordable alternative to X-ray CT for children, as well as a cheaper and more precise alternative to dual-energy x-ray absorptiometry
(DXA) screening for osteoporosis.
Space-based applications include studies of bone and muscle loss, monitoring renal stores and effects of radiation, and imaging changes in cardiovascular function. Also, a compact MRI can image body-wide fluid shifts and would be very useful in studying intracranial pressure (ICP), which in recent NASA studies (such as outlined in the February 9th, 2012 ISS press release on "Astronaut Visions Changes Offer Opportunity for More Research
" and the NASA human research road map on the Risk of Spaceflight Induced Hytracranial Induced Hypertension/ Vision Alterations
) have been associated with serious vision impairments in astronauts.
The compact MRI project involves partners from the University of Saskatchewan, Loma Linda University
, NRC IBD, MRI-Tech and COMDEV International
. To date, TRASE and Halbach parts have been built and had separate preliminary verifications.
|The transmit array spatial encoding (TRASE) RF image encoding. Photo c/o Gordon Sarty University of Saskatchewan.|
The next step for Sarty and his team is to build a technology development model (TDM) followed by a complete prototype. Then comes the building of the pilot plant, FDA approval and finally full commercialization. These are estimated to take five years and will cost tens of millions of dollars, most of which still needs to be raised.
Sarty and his team are currently attempting to raise an initial investment of $2M to begin the process.
“The idea of simplifying and making portable MRIs is somewhat of a holy grail among researchers and developers
”, states Sarty. “Our TRASE/Halbach approach is unique and will remain that way until someone buys a license for the TRASE patents from NRC