IEEE Spectrum November, 2013 - 11

the world's
most powerful
mri takes shape
Medical researchers expect
unprecedented resolution
an MRi scanner equipped with a superconducting magnet strong
enough to lift a 60-metric-ton battle tank will offer unprecedented
images of the human brain when it comes on line a little more than
a year from now, say its builders.
The imager's superconducting electromagnet is designed to produce a field
of 11.75 teslas, making it the world's most powerful whole-body scanner. Most
standard hospital MRIs produce 1.5 or 3 T. A few institutions, including the
University of Illinois at Chicago and Maastricht University, in the Netherlands,
have recently installed human scanners that can reach 9.4 T. Superconducting
magnets used in the Large Hadron Collider, which last year was used in the
discovery of the Higgs boson, produce a field of 8.4 T.
The development of the scanner, known as INUMAC (for Imaging of Neuro disease
Using high-field MR And Contrastophores), has been in progress since 2006 and is
expected to cost €200 million, or
about US $270 million. The project reached a key milestone this
summer with delivery of more
than 200 kilometers of superconducting cable, which is now being
wound into coils that will produce the scanner's magnetic field.
"We're pretty proud of having met all the requirements,
plus given them a little extra,"
says Hem Kanithi, vice president of business development
at Luvata, in Waterbury, Conn.,
which built the superconductor.
Standard hospital scanners
have a spatial resolution of about
1 millimeter, covering about
10 000 neurons, and a time
resolution of about a second.

The INUMAC will be able to image an area
of about 0.1 mm, or 1000 neurons, and see
changes occurring as fast as one-tenth of a
second, according to Pierre Védrine, director of the project at the French Alternative
Energies and Atomic Energy Commission,
in Paris. With this type of resolution, MRIs
could detect early indications of brain diseases such as Alzheimer's or Parkinson's and
perhaps measure the effects of any methods
developed to treat those illnesses. It would
also allow much more precise functional
imaging of the brain at work than is currently available. "You cannot really discriminate today what is happening inside your
brain at the level of a few hundred neurons,"
Védrine says.
High-field MRI could also allow scientists
to explore different methods of imaging.
Most MRI machines rely on imaging the
nuclei of hydrogen atoms, but stronger
scanners might gain useful physiological
information by looking for weaker signals
from sodium or potassium nuclei.
Improved superconducting wire is key
to making such a powerful machine. The

secondary coiL
Liquid heLium
main superconducting coiL

thiS onE goES to 11: The main superconducting
coil for the INUMAC imager is made from 170 kilometers
of niobium-titanium. When bathed in liquid helium and
charged, it produces a magnetic field of 11.75 teslas.

nEwS

illuStRation by

Emily Cooper

SPECTRUM.IEEE.ORG

nORTh aMERICan

nOV 2013

http://SPECTRUM.IEEE.ORG

Table of Contents for the Digital Edition of IEEE Spectrum November, 2013