Rinsho Shinkeigaku (Clinical Neurology)

The 48th Annual Meeting of the Japanese Society of Neurology

Amyloid imaging

Kenji Ishii, M.D.

Positron Medical Center, Tokyo Metropolitan Institute of Gerontology

Amyloid imaging has recently emerged as a non-invasive neuroimaging technique to visualize the accumulation of amyloid-beta in living brain. Several modalities such as PET, SPECT, MRI, and optical imaging has been adopted for this purpose, the nuclear medicine technique of PET firstly put it to practical use because of its high sensitivity. Among many radioligand tracers proposed, Pittsburgh Compound-B (PIB) has successfully spread over the world as a standard amyloid imaging probe. Several lines of evidence from PIB-PET study have suggest that the accumulation of amyloid beta start during the preclinical stage of Alzheimer's disease (AD) and reaches plateau phase before or during the MCI stage. Therefore, the amyloid imaging may be useful as a biomarker of AD, not only for the very early specific diagnosis, but also for the monitoring the therapeutic effect with agents that reduce the accumulation of amyloid-beta in the brains of AD. The amyloid imaging technique is also useful to differentiate non-AD type degenerative disorders such as argiophilic grain dementia and neurofibrillary tangle dominant dementia, which are cumulatively called as tauopathies. In order to evaluate its diagnostic power, and pathophysiological significance of accumulation, further prospective study and pathology-PET comparison are essential.

(CLINICA NEUROL, 47: 915|917, 2007)
key words: Alzheimer's disease, amyloid, PET, early diagnosis, surrogate marker

(Received: 16-May-07)