Physicists are developing new electronics for identifying subatomic particles in high-energy accelerators that may also enable radiologists to detect cancer at an earlier, more curable stage.
?The electronics needs in medical imaging look very closely related to the needs we have in high-energy physics,? said Henry Frisch, Professor in Physics at the University of Chicago. ?Physics tends to advance by new capabilities in measurement, the same in radiology.?
Radiologists, medical physicists and high-energy physicists share a desire to more precisely measure the velocity and location of subatomic particles, Frisch explained. A significant improvement in Positron Emission Tomography technology could mean the difference between life and death for some patients, said Chin-Tu Chen, Associate Professor in Radiology at the University of Chicago. Being able to detect a tumor measuring a quarter of an inch in diameter rather than half an inch would mean initiating treatment when the disease mass is eight times smaller by volume.
Frisch, Chen and physicist Karen Byrum of Argonne National Laboratory are pursuing the joint effort with initial funding provided by the U.S. Department of Energy, Argonne and the University of Chicago Cancer Research Center. Their work is part of an international scientific trend to apply high-energy physics technology to biomedical imaging techniques.
While medical physicists look for disease, high-energy physicists seek to identify what types of subatomic particles they produce in collider experiments. The identity of many such particles remains a mystery, and thus a barrier to some potentially dramatic new insights into the operation of the universe at the smallest of scales.
Today?s high-energy physics experiments typically measure particle velocities to within an accuracy of 100 picoseconds (a trillionth of a second). A photon of light can travel approximately one inch in 100 picoseconds. Frisch would like to increase the resolution to one picosecond.
?We are not as ambitious as Henry,? Chen said. ?We are aiming more toward 30 picoseconds.?
In the PET world, more accurate particle velocity measurements would translate into improved image quality and thus more accurate diagnoses, Chen said. Doing so would require an emerging technique called ?time-of-flight PET,? which provides a positional measurement that conventional PET technology lacks.
In recent years, the development of faster crystals has renewed biomedical interest in the technique, as Frisch learned when he and Argonne?s Karen Byrum organized a November 2005 workshop of picosecond particle measurements. The workshop brought them together with Chen and Patrick Le D? of the French atomic energy commission.
Le D? and Frisch had worked together almost 20 years ago to develop an instrument for the ill-fated Superconducting Supercollider. Nevertheless, ?It was a complete surprise to find out that we were thinking along absolutely parallel lines,? Frisch said of the ideas that Le D? presented in his talk.
Scientists all over Europe, in fact, now work in concert to develop time-of-flight PET technology. Frisch, Chen, Kao and Byrum, meanwhile, have formed their own biomedical imaging effort that includes the Electronics Design Group at the University of Chicago?s Enrico Fermi Institute.