 There are no approved ways to measure amyloid load in humans. Several compounds are under investigation. All of these compounds use radioactive chemical tags for positron emission tomography PET imaging. The most promising compound is 11C-PIB, or Pittsburgh Compound-B. This compound can be injected and a PET scan performed. This allows doctors to see the amyloid plaques in the brain, and to use this information to look at other types of dementia to see if there are differences andor similarities in the plaques. 