Nano-magnets enhance MRI brain-imaging
Nanotechnology may make MRIs even better at monitoring brain function and activity. (Cancer.gov)
Scientists have engineered tiny, nano–sized magnets that can be combined with MRI technology to learn more about our most complex organ: the brain.
MRI stands for Magnetic Resonance Imaging. Alan Jasanoff at MIT hopes nanotechnology can help make MRI technology even better at revealing how a live brain functions.
Alan Jasanoff: It’s possible to monitor brain activity already using MRI, and that’s done by measuring aspects of blood flow that change in the brain during thinking and behavior.
The tiny, nano–sized magnets engineered by Jasanoff’s team cluster together when they encounter calcium in the brain. That’s important, Jasanoff said, because calcium plays a role in the way brain cells – called neurons — communicate.
Jasanoff: It turns out that part of neurons’ machinery for releasing chemicals, which are called neurotransmitters, involves taking up calcium from the surrounding medium.
The ability to use these invisibly small magnets inside a brain is at least several years away.
But if the magnets are approved for use in people, he said, they could help us understand and possibly cure brain disorders such as epilepsy and schizophrenia.
Our thanks to the National Science Foundation.
Jasanoff said, “It’s possible to monitor brain activity already using MRI, and that’s done by measuring aspects of blood flow that change in brain during thinking and behavior. Looking at what brain is doing by checking its blood flow is like trying to understand how a computer works by feeling which parts of the computer are hot. In other words, it’s a very gross sort of energy related measure, because blood flow goes up to a part of the brain that’s more active because it needs to bring in more nutrients, oxygen, etc.”
“With calcium related approach,” he said, “we get instead a much more precise readout of what’s going on in individual cells and it’s something, for instance, that could allow us to label groups of cells with agent and monitor what individual components of the circuit are doing.”
He explained more about the process, saying, “They are obviously nano–sized particles that include superparamagnetic iron oxide and that have been sensitized to calcium. And how is that done. Well, it turns out that by making nanoparticles cluster reversibly in the presence of some sort of target molecule or signal, their ability to influence MRI contrast can be manipulated. So for instance, if nanoparticles cluster in presence of calcium, the image of the specimen containing the nanoparticles will be more darkened in the presence of calcium than in the absence of calcium. So, at a molecular level, what’s going on is particles are clustering (or in some cases become less potent). This provides mechanism to couple the presence of something you’re trying to detect to a change in the image.”
Our thanks to:
Alan Jasanoff
Assistant Professor of Nuclear Science and Engineering
Deparment of Brain and Cognitive Sciences
