"It is advisable for patients to stop caffeine intake for a 24-hour period prior to imaging," said SNM member Medhat M. Osman, M.D., Sc.M., Ph.D., assistant professor in the department of internal medicine's division of nuclear medicine and director of PET at St. Louis University Hospital, St. Louis, Mo. The study, "Correlation Between Myocardial Uptake and Caffeine Intake: Detection With FDG PET/CT," traced the relationship between caffeine intake and myocardial uptake detected by whole-body PET/CT.
PET is a powerful medical imaging modality that noninvasively (nonsurgically) uses special imaging systems and radioactive tracers to produce pictures of the function and metabolism of the cells in the body. CT is an X-ray test that generates a detailed view of the anatomy or structure of organs and tissues in the body. Fused together, PET and CT images can more accurately define a host of diseases processes than can conventional, anatomic-based imaging alone (such as CT and MRI) and can play an important role in cardiac and neurologic imaging.
Most PET scans today are performed with an imaging radiopharmaceutical--most commonly FDG (fluorodeoxyglucose)--that can be tracked by a PET scanner. Where FDG goes in the heart--its uptake into an organ, a tissue, a cell or body fluids--provides a picture of the heart's function. If a person exercises before having a PET/CT scan, more FDG uptake is noted. The researchers found that the same thing happens with caffeine: The heart beats faster when you drink coffee, just as it does when you exercise. Patients who had coffee before their scans had a "significantly higher" myocardial uptake tha
Contact: Maryann Verrillo
Society of Nuclear Medicine