PET Imaging of Peripheral Benzodiazepine Receptors

Study Summary

This study will use positron emission tomography (PET) to measure a receptor in the brain that is involved in inflammation. It will test two radioactive chemicals used in the procedure to see if the newer chemical, \[(11)C\]B, is as good or better than the older one, \[(11)C\]A, for measuring brain inflammation. Healthy volunteers 18 years of age and older may be eligible for this study. Participants undergo an evaluation, \[(11)C\]A PET scan, \[(11)C\]B PET scan and magnetic resonance imaging (MRI), as follows: Evaluation Medical history and physical examination, blood and urine tests PET scans * \[(11)C\]A scan. A catheter (plastic tube) is placed in an arm vein for injection of the \[(11)C\]A isotope. Some patients also have a catheter placed in an artery in the wrist to collect arterial blood samples during the scan. Subjects then lie on the scanner bed and a special mask is fitted to the head to help keep the subject s head still during the procedure. Following an 8-minute scan to calibrate the scanner, the \[(11)C\]A is injected into the catheter in the vein and pictures are taken that show where chemicals related to inflammation are present. The procedure takes about 2.5 hours. * \[(11)C\]B scan. The procedure is the same as above for \[(11)C\]A, except the isotope used is \[(11)C\]B. MRI scan. This test uses a strong magnetic field and radio waves to obtain images of body organs and tissues. The subject lies on a table that can slide in and out of the scanner (a metal cylinder), wearing earplugs to muffle loud noises that occur during the scan. ...