New molecular tags could allow MRI to track changes in the body
DURHAM, N.C., March 28 (UPI) -- The most common method of magnetic resonance imaging makes biological processes visible for seconds, but scientists have found a molecule that could allow them to observe the body at work for an hour or longer.
Duke University scientists found a group of molecular tags can increase MRI signals by 10,000 times, allowing a much longer time for images to be taken, and potentially allowing doctors to monitor conditions such as heart disease in real time.
MRI uses a strong magnetic field and a series of radio waves to induce hydrogen atoms in cells to "broadcast" their location. The technique is not very sensitive, though, making it difficult to see smaller groups of cells or track slower biological processes.
Using a new technique to hyperpolarize molecules, turning them into "lightbulbs" that burn far longer than the typical reaction in an MRI, the researchers say better imaging may also lower its cost.
"It's hard to take an image with an agent that is only visible for seconds, and there are a lot of biological processes you could never hope to see," Dr. Warren Warren, a professor at Duke University, said in a press release. "We wanted to try to figure out what molecules could give extremely long-lived signals so that you could look at slower processes."
For the study, published in the journal Science Advances, the scientists synthesized a series of molecules that contain diazirines -- two nitrogen atoms bound in a ring. In the lab, the scientists mixed the diazarines with hydrogen and a catalyst, hyperpolarizing the molecules with diazirines, finding they could be detected for over an hour, unlike traditional MRI methods.
The scientists said diazirine-containing molecules are promising because they can be tagged on a variety of molecules and proteins, but that further research is needed as to its larger use for MRIs.
"You could envision, in five or ten years, you've got the container with the catalyst, you've got the bulb with the hydrogen gas. In a minute, you've made the hyperpolarized agent, and on the fly you could actually take an image," Warren said. "That is something that is simply inconceivable by any other method."
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