PET/CT may be the king of molecular imaging today but in 1991, it was just an idea in Geneva.

That's when and where engineer Ronald Nutt and physicist David William Townsend came up with the hybrid scanner that has revolutionized the practice of diagnostic oncology.

"I had been working on the design and development of PET scanners for many years and came to realize that the power of functional imaging such as PET was limited by the lack of good anatomical detail of the sort offer by CT," Townsend wrote in an e-mail to DOTmed News. "Since disease such as cancer begins with a functional abnormality, PET imaging offers the possibility of earlier diagnosis. PET could therefore identify a potential abnormality early in the disease process but not accurately localize the abnormality. Combining PET with CT gave the best of both worlds -- identify and localize a tumor at an early stage," he said.

Nutt and Townsend were awarded the 2010 IEEE Medal for Innovations in Healthcare Technology, an award sponsored by the IEEE Engineering in Medicine and Biology Society.

"Dr. Nutt and I felt extremely honored since this is a society-wide medal and it is the first year it has been awarded," said Townsend.

The PET/CT scanner was named the Medical Invention of the Year in 2000 by TIME magazine. Major manufacturers have since abandoned the production of stand-alone PET scanners.

The two inventors had no idea that the PET/CT scanner would have such a deep impact on the molecular imaging industry.

"At the time we were designing and building the first PET/CT prototype, we never imagined that one day, all PET scanners would incorporate CT," said Townsend. "I think the rapid adoption of the technology by the medical profession surprised many people, especially Dr. Nutt and I."

Since the proliferation of the scanner into the market, both inventors have been keeping busy.

Nutt co-founded CTI Molecular Imaging in 1983 and has been heavily involved in PET technology for several decades. Currently, he is the chairman of the board of ABT Molecular Imaging, Inc., a Tennessee-based company responsible for the development of the Biomarker Generator, which produces on-demand radiopharmaceutical doses.

Townsend is currently the head of PET and SPECT development for the Singapore Bioimaging Consortium under the Agency for Science, Technology and Research. He is also a professor of radiology at the Yong Loo Lin School of Medicine at the National University of Singapore. Townsend is leading a team of researchers who are working on the development of single photon and positron-emitting radiotracers for pre-clinical imaging of disease.

"The opportunity to work with multi-disciplinary teams is what inspired me to move from particle physics to medical imaging in 1980," said Townsend. "I have never regretted that decision and as our work has impacted the lives of patients and health care, it has become an increasingly rewarding environment."

The inventors received their medal on June 26 at the IEEE Honors Ceremony in Canada. IEEE is the world's largest technical professional association.

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