New MRI technique tracks low concentration molecules in body
23 October 2011
Researchers at Lund University have built a new type of MRI
scanner that can study molecules normally only found in very small
concentrations, directly in organs and tissue.
Researchers from the Department of Neuroscience and the
University's Bioimaging Centre have managed to construct an
instrument that ‘hyperpolarises’ the molecules and thus makes it
possible to track them using MRI.
The technique opens up new possibilities to study what really
happens on molecular level in organs such as the brain. It has
applications in areas as varied as neuroscience, diabetes, cancer,
Magnetic resonance imaging (MRI) is an established technique
which over the years has made it possible for researchers and
healthcare professionals to study biological phenomena in the body
without using ionising radiation, for example X-rays.
The images produced by normal MRI are, to put it simply, pictures
of water in the body, since the body is largely made up of water.
MRI produces images of the hydrogen nuclei in water molecules. It
can also be used to study other types of nuclei in many other
The only problem is that the concentration of molecules that are
interesting to track is so low that they are not visible on a normal
MRI scan. It is this problem that the researchers have now solved by
constructing a ‘polariser’.
In the polariser, the researchers
make these molecules visible to the MRI scanner by hyperpolarising
them. The molecules are then injected into their natural body
“Then we can follow the specific molecule and see the reactions
in which it is involved. This gives us a unique opportunity to see
and measure enzymatic reactions directly in the living tissue”,
explains Deniz Kirik, Professor of Neuroscience.
The technology could be used to study molecules in many different
types of tissue in the body. Prof Kirik will focus on developing
this technology to study the brain — something which has not been
Deniz Kirik, Vladimir Denisov, Lund University
Bioimaging Center, head of the technical development within the
project and Sandra Cuellav-Baena som är dPhD student in Prof Deniz
Kirik's research group BRAINS
“The brain is not an easy target!” he observes. “When we look
inside the brain today using MRI, we see the molecules that are most
numerous. However, it is rarely these common molecules we want to
study. We want to study how molecules that have a low concentration
in the tissue behave, for example how signal substances are
produced, used and broken down. It is when these processes don’t
work that we become ill.
“This technology has the potential to help us do just that. If we
can make it work, it will be a breakthrough not only for
neuroscience but also for other research fields such as diabetes,
cancer and inflammation, where similar obstacles limit our
understanding of the basic molecular processes which lead to
Professor Hindrik Mulder is one of the co-applicants for the
project and he will develop and use the technology in diabetes
research. Dr Vladimir Denisov from the Lund University Bioimaging
Centre is leading the technical development within the project.
At present there are only a few polarisers in the world and
Lund’s newly built device is the only one in Scandinavia to be fully
available for academic research.
“All the other equivalent instruments are purchased commercially
and come with restrictions placed by the manufacturer. We therefore
chose to take the longer and more complicated route of building the
instrument ourselves”, explained Prof Kirik.
Now that the instrument has become operational, the researchers
have started on the first experiments.
“This is the first of two steps”, says Deniz Kirik. “The next
step in this frontline research is to develop the unique technology
by constructing an even more sophisticated polariser which will
enable advanced experiments on animal models for various diseases.”