The creation of the hybrid positron emission tomography (PET)/computed tomography (CT) scanner by Ronald Nutt and David W. Townsend revolutionized diagnostic medical imaging and has enabled earlier detection of cancer and better monitoring of treatment efficacy. Introduced in 1999, the PET/CT scanner incorporates the individual strengths of existing CT and PET technology while overcoming their respective stand-alone limitations. The hybrid PET/CT scanner provides precise spatial registration of anatomy and function in a single diagnostic imaging examination. The original idea for the PET/CT scanner came when Drs. Nutt and Townsend, while working together on a PET scanner design, recognized the opportunity for integrating CT components into the gantry of an existing PET design. Dr. Townsend led the academic efforts to develop PET/CT methods and conduct the first human studies using the scanner. Dr. Nutt was instrumental in building the first prototype PET/CT system as well as developing the first commercial versions. The PET/CT scanner was named “Medical Invention of the Year” in 2000 by Time magazine. The technology was quickly adopted by industry, with more than 95% of all PET scanners sold in 2004 being PET/CT scanners. By 2006, practically all stand-alone PET scanners had been replaced by PET/CT scanners.
Dr. Townsend is considered the leading authority on hybrid imaging systems as well as one of the pioneers of three-dimensional PET and its required reconstruction algorithms. An IEEE Fellow, he is currently head of PET and SPECT development for the Singapore Bio-imaging Consortium under the Agency for Science, Technology and Research and Professor of Radiology, National University of Singapore.