New positron emission tomography (PET) probes that bind specifically to amyloid plaques are promising candidates for quantifying plaque burden noninvasively. A positron-emitting chemical compound, Pittsburgh Compound B (PIB), binds specifically to amyloid plaque and can be used to image Alzheimer’s disease using PET. The image on the left is the brain of a normal person, and the blue colors indicate little accumulation of PIB. The image on the right is the brain of a person with Alzheimer’s disease, and the yellow to red colors indicate large accumulations of PIB and thus the presence of amyloid plaque.

SOURCE: Klunk, W.E., H. Engler, A. Nordberg, Y. Wang, G. Blomqvist, D.P. Holt, M. Bergstrom, I. Savitcheva, G.F. Huang, S. Estrada, B. Ausen, M.L. Debnath, J. Barletta, J.C. Price, J. Sandell, B.J. Lopresti, A. Wall, P. Koivisto, G. Antoni, C.A. Mathis, and B. Langstrom. 2004. Imaging brain amyloid in Alzheimer’s disease with Pittsburgh Compound-B. Ann. Neurol. 55:306-319. Printed with permission from John Wiley & Sons, Inc.