New CT detectors promise sharper images

New CT detector technologies are being developed because “today’s CT detectors use scintillator materials and they are not perfect,” said Dr. Norbert Pelc in a talk presented on behalf of the author, Willi Kalender, PhD, from the University of Erlangen. Kalender couldn’t attend this year’s meeting due to a broken arm.

What kind of CT detector would be ideal? The next generation of detectors is a tall order by any measure, said Pelc, who is a professor of radiology and bioengineering at Stanford University. Kalender is a professor and chairman of the Institute of Medical Physics at the Friedrich-Alexander-University Erlangen-Nuremberg in Germany.

The ideal CT detector for a scanner would offer 100% absorption efficiency, so that “it would detect all of the x-rays incident on it,” Pelc said. “In order to do that, it would also need to have 100% geometric efficiency and not lose any photons because they don’t hit any nonsensitive parts of the detector. The signal would come out immediately, so it would have no signal lag or afterglow,” he said, referring to the energy that continues to emerge from even the fastest scintillator detectors once switched off.