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February 20, 2006
High-powered MRI provides tools for Emory and beyond

By Holly Korschun

A state-of-the-art magnetic resonance imaging (MRI) machine recently installed in the School of Medicine may be just the tool for advancing basic and translational biomedical research. As the only 9.4 Tesla MRI machine in Georgia, the device can detect and provide images of areas with diameters as small as one-tenth of a millimeter in size, about the equivalent of a human hair.

MRI systems create visuals of body composition and mechanisms by surrounding the subject with a powerful magnetic field, which, in conjunction with radio waves, results in a signal and then images. The power of an MRI machine is calculated based on the strength of the magnetic field, measured in units of Tesla (T). Amounts of Tesla subsequently determine the resolution of the resulting image. Clinical MRI machines operate using 1.5 Tesla, and scientists estimate that the earth’s magnetism is one-20,000th (.00005) of a Tesla.

While less powerful MRI machines at Emory already allow researchers to see detailed anatomical structures within the body, such as abnormal tissue, the 9.4T MRI has increased resolution and the capacity to track physiological functioning of animal research subjects.

Access to the 9.4T MRI will be coordinated by the Biomedical Imaging Technology Center and the Coulter Department of Biomedical Engineering at Georgia Tech and Emory.

Shella Keilholz, assistant professor of biomedical engineering, came to Emory in 2004 in part because of the 9.4T MRI’s potential to further research. She estimates that no more than 20 MRI machines of similar power are in use around the world.

“We can measure a lot of things with this magnet: We can look at structure; we can look at blood flow,” Keilholz said. “We can see volume, amounts of oxygenation and water distribution. We can make maps of the principal directions of diffusion, and that tells us what the microstructure in the brain is like.”

MRI also enables diverse investigations without harming research subjects. “The beauty of MRI is that it allows you to do all of this non-invasively,” said Xiaoping Hu, director of the Biomedical Imaging Technology Center and a Georgia Research Alliance Eminent Scholar in imaging. “You can perform longitudinal studies, follow-up studies, or you can look at animals during interventions. This is really the main advantage to having MRI.”

To fully utilize the 9.4T MRI, research projects in development include an investigation of how learning impacts the brain, studies of spinal cord and cardiac function, and the generation of models showing how diseases spread.

Emory scientists will develop techniques to increase and improve appropriate usage of MRI systems. One such focus will be on refining contrast agents, used to more clearly trace physiological movement within the body. For example, in research on Alzheimer’s disease, which may be affected by the build-up of protein plaque in the brain, those contrast agents and the resulting images may someday lead to earlier diagnosis and superior therapies.

“Right now MRI used for looking at Alzheimer’s is not very effective,” Hu said. “If we could somehow detect these plaques early, it could lead to early intervention or, at least, better treatment.”

Other potential applications may involve observing drug diffusion in the body. “If people want to know some pharmaceutical or chemical effect, [MRI] is very important,” said Fuqiang Zhao, assistant professor of biomedical engineering. “You can see what those drugs do to the brain or the heart.”

Now that the 9.4T MRI is in place and fully functional, Emory researchers are planning interdepartmental collaborations, as well as partnerships with other Atlanta-area institutions, including Georgia State University. The MRI may soon be available to help other area institutions with their own research. The scanner also represents a powerful tool available to researchers in the Center for Behavioral Neuroscience.

“We would offer pilot machine time for investigators interested in finding out if the 9.4T scanner is appropriate for answering their questions,” Hu said.

The 9.4T MRI, manufactured by Bruker BioSpin MRI, was purchased with funds from the Georgia Research Alliance and the Whittaker Foundation.

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