Siemens reveals R&D work on scanner that combines CT and PET technologies

Hybrid device adds BGO detectors to CT gantry

Executives with the nuclear medicine division of Siemens Medical Systems in Hoffman Estates, IL, this month confirmed rumors about the company's efforts to build a hybrid CT/PET scanner. While the system is still in the early prototype phase, Siemens hopes that the unit could eventually result in a product capable of providing both anatomical and metabolic information in a single scan.

Siemens has long been rumored to be working on a hybrid CT/PET machine, but until this month's Society of Nuclear Medicine meeting in Toronto, the company had been tight-lipped about its work. At the SNM meeting, however, Siemens nuclear medicine division group vice president Barbara Franciose acknowledged the company's development of the device.

The first prototype CT/PET hybrid has been built and is installed at the University of Pittsburgh, Franciose said, where research on the system is being headed by Dr. David Townsend. The system consists of a Siemens Somatom Plus CT scanner, with a second ring of PET BGO detectors complementing the system's conventional ring of x-ray detectors. The system produced its first image the week before the SNM conference.

Siemens' goal in developing the scanner is to provide physicians with a more elegant way to merge anatomical detail, such as that collected with a CT scanner, with the metabolic information provided by PET. Image fusion techniques are already available that allow users to meld such data with software, but these methods require image registration and require patients to be scanned on two separate machines.

A hybrid system would make things easier for both patients and physicians and would also mesh with long-term trends in Siemens' medical imaging product development efforts, such as in oncology imaging, according to Franciose.

"If you envision imaging 10 years from now, there won't be separate machines. There will be combination machines," she said. "Siemens has strategically made a lot of investment in disease management, and we feel that this is a prototype that is on that same wavelength."