Report from ISMRM: Pettigrew reveals his vision of medical imaging's future

At a conference increasingly associated with metabolic and physiologic imaging, Dr. Roderic Pettigrew, director of the National Institute of Biomedical Imaging and Bioengineering, shared his vision of 21st century radiology.

His plenary lecture during the ISMRM opening session on Saturday took its lead from Princeton University President Shirley Tilghman, who credited technological innovation as the engine of scientific advancement at the 50th anniversary of DNA's discovery in May.

Medical imaging is a prime example how of new instrumentation leads to discovery, Pettigrew said. He predicted that imaging innovation would be essential to the realization of the National Institutes of Health's "road map to discovery." Lines of scientific investigation associated with the plan involve different types of research teams for the future and a reengineering of the clinical research enterprise.

Emerging technologies play a prominent role in each initiative.

"Molecular imaging was identified by a broad spectrum of scientists at NIH as a key focus area," Pettigrew said.

Other important areas of research will lead to improved in vivo identification of protein structures and interactions. Informational and computational biology will play a role, and nanotechnology will rise in prominence and find a place with MRI in image-guided diagnosis and intervention, he said.

The research teams that will do the heavy lifting in these areas will be highly interdisciplinary: Imaging scientists will work with geneticists, biochemists, physicists, engineers, mathematicians, and computer software developers. The high costs and risk involved in realizing the goals of the NIH roadmap require partnerships among public agencies, institutions, and the private sector, Pettigrew said.

The NIBIB will focus on breakthrough technologies that facilitate the fundamental understanding of complex biological processes. The institute will emphasize the development of instruments for molecular imaging, image-guided interventional medicine, and computational applications, he said.

In molecular imaging, the goal is personalized diagnosis and therapy, according to Pettigrew. The challenge is to create in vivo imaging techniques capable of imaging individual molecular events. The gap between conventional and molecular imaging can be measured in the limitations of current imaging technology - the best in vivo resolutions achievable today is still 1000 times too low.

For examples of possible solutions, Pettigrew referred to the work of Dr. David Piwnica-Worms at Washington University in St. Louis and Dr. Ralph Weissleder and Dr. Umar Mahmood at Massachusetts General Hospital. Their reporter gene and activatable probe strategies suggest how a small quantity of molecules can be used to generate enough signal to demonstrate that subcellular changes in a targeted gene have taken place.

Examples of promising image-guided surgical techniques include Dr. Hunter Peckham's work at Case Western Institute on deep brain stimulation to implant electrodes that effectively treat Parkinson's disease tremor. Dr. King Li, director of intramural diagnostic imaging at the NIH, is developing techniques for image-guided genomics to trigger contrast enhancement in regions of gene upregulation. MRI-compatible catheter and wire antenna technologies are also being developed to aid navigation and targeting during stem cell implantation.

New computer applications are also needed to process and display functional and metabolic data in ways that can be easier understood and interpreted, according to Pettigrew.

"We are talking about more than traditional image processing. We need innovations that model complex biological systems so we can be more intelligent and predictive about disease," he said.

Volume rendering techniques, for example, have been used to present "flattened" views of the visual cortex to enable physicians to examine in two dimensions diffusion-weighted MRI patterns associated with macular degeneration. Blood oxygen level-dependent imaging performed at 7T at the University of Minnesota is helping researchers create maps of neuronal activation associated with the auditory system at the cellular level.

Pettigrew expressed confidence that the goals of the NIH road map will be realized with the help of imaging science.

"We are looking forward to an era of personalized medicine consequent to technological innovations that we, as imaging scientists, will create," he said.