Zahi Fayad, PhD

CHICAGO--With atherosclerosis-related diseases estimated to cost more than $500 billion in the U.S. in 2010, prevention, diagnosis and treatment of vascular disease are critical priorities. Existing and emerging imaging tools show great promise in helping the diagnosis of atherosclerosis, said Zahi A. Fayad, PhD, professor of radiology and cardiology at Mount Sinai Medical Center in New York City, during the opening session panel at the 97th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA) on Nov. 27.

Preventing death from cardiovascular diseases hinges on reducing risk factors such as tobacco use, unhealthy diet and physical inactivity and accurate diagnosis of atherosclerosis, said Fayad.

Fayad reviewed characteristics of stable and ruptured plaque, explaining that features of ruptured plaque, which include minimal stenosis and a thin fibrous cap, require detection via imaging.

Current tools provide some capabilities for plaque assessment, Fayad said. MRI, for example, can be used to identify the plaque burden. Diffusion-weighted MRI takes assessment one step farther and can be used to identify the composition of plaque, and dynamic-contrast enhanced MRI provides imaging data on the angiogenesis of inflammation.

However, further development and improvement is needed, said Fayad, adding that FDG-PET offers another promising avenue, and researchers are examining the hybrid technique as a biomarker for measurement of inflammation.

The holy grail for cardiac imaging, however, rests in the ability to predict a subsequent atherosclerotic event. PET may provide the capability, said Fayad, who shared preliminary data from studies of cancer patients. The research suggests that higher FDG uptake in the vasculature correlates with increased likelihood of future events. Additional research and trials are needed, said Fayad.

Another area of PET development comes on the tracer front, with more specific tracers under development. For example, 18 NAF PET imaging may provide a marker of active calcification.

Finally, Fayad predicted that MR/PET will have a tremendous impact in atherosclerotic imaging and provides quantitative data to assess disease burden.

Despite the excitement about MR/PET, the field continues to evolve. Fayad reviewed current areas of research such as improved detector technology, spectral CT and multicolor molecular CT. He also said, “Cardiovascular nanotechnology offers a great opportunity to detect disease before health has deteriorated, deliver therapy and develop research tools to enhance understanding of cardiovascular disease.”