Dancing atoms now understood( In developing a model to explain the...)

In developing a model to explain the motion of atoms in a magnetic field, scientists have overcome a decades-old obstacle to understanding a key component of magnetic resonance.

The new understanding may eventually lead to better control of magnetic resonance imaging (MRI) and higher resolution MRI diagnoses.

Collaborators at Ohio State University in Columbus and three institutions in France--the Centre National de la Recherche Scientifique, the Universit d'Orlans, and the Universit de Lyon--presented their findings in a paper that appears early online Nov. 25, 2008, in the Journal of Chemical Physics.

"This is very exciting work", said Tanja Pietra, the program officer at the National Science Foundation who partially supported this project. "The fact that the researchers did not set out to work on this problem but more or less stumbled upon it and then used their ingenuity to solve it, demonstrates the importance of conducting basic research. In this case, the work may have a major impact on magnetic resonance imaging, positively affecting many peoples' lives."

The key breakthrough is a new understanding of a type of physical process called adiabaticity. Adiabatic processes are what physicists and engineers routinely use to control atoms in nuclear magnetic resonance (NMR) spectroscopy, and its better known sister, MRI.

"An adiabatic process can be visualized as one where a system is 'held tightly'and slowly dragged by a controlling force from one state to the next," said chemist Philip Grandinetti of Ohio State. In MRI, magnetic energy holds the atoms in a patient's body in a steady state while radio waves are the controlling force that drags the atoms from one state to the next. "In a 'perfect' adiabatic process, the controlling force is moved infinitely slowly with the system's trajectory locked to the controlling force's trajectory," said Grandinetti.

Both NMR and MRI exploit a pe
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