Amyloid plaque imaging in vivo: current achievement and future prospects.

Introduction: Alzheimer's disease (AD) is a very complex neurodegenerative disorder, the exact cause of which is still not known. The major histopathological features, amyloid plaques and neurofibrillary tangles, already described by Alois Alzheimer, have been the focus in research for decades. Despite a probable whole cascade of events in the brain leading to impairment of cognition, amyloid is still the target for diagnosis and treatment.

Discussion: The rapid development of molecular imaging techniques now allows imaging of amyloid plaques in vivo in Alzheimer patients by PET amyloid ligands such as Pittsburgh compound B (PIB). Studies so far have revealed high (11)C-PIB retention in brain at prodromal stages of AD and a possibility to discriminate AD from other dementia disorders by (11)C-PIB. Ongoing studies are focussing to understand the relationship between brain and CSF amyloid processes and cognitive processes.

Conclusion: In vivo imaging of amyloid will be important for early diagnosis and evaluation of new anti-amyloid therapies in AD.