Specifically, FDG-PET imaging of tumors has been shown to provide utility in diagnosis and staging not found in competing modalities. The other two major applications for PET are neurology, including the imaging of epilepsy and dementia, and cardiology, which includes the diagnosis of coronary artery disease and myocardial viability. Neurological use of PET has been slow to develop partly because there have been no therapies available for degenerative disorders like Alzheimer's and Parkinson's disease, said Dr. J. James Frost, a professor of radiology and neuroscience at Johns Hopkins University. That situation may be changing, as drug companies are on the track of neuroprotective therapies. Although the utility of fMRI is still being investigated, it shows considerable potential in the brain, said Christopher Chabris, Ph.D., a research fellow at Harvard University.
People can do a variety of mental tasks in one session.
For these applications, a combination of functional MRI and anatomical MRI is the big leader. While oncology dominates PET services overall, there are a number of centers that successfully focus on the heart. These sites bring in business despite the less favorable reimbursement climate for cardiac applications, said Dr. K. Lance Gould, a professor of cardiology at the University of Texas, Houston. It is a very sensitive marker of changes in perfusion capacity that can reflect diffuse coronary artery disease before there are any flow-limiting stenoses. The ability to provide very early diagnoses of coronary artery disease potential with PET enables physicians to better manage at-risk patients with drugs and dietary and lifestyle changes before more invasive therapies are needed, Gould said.