- The major pathologic features that characterize AD are senile plaques, neurofibrillary tangles, decreased synaptic density, neuron loss, and cerebral atrophy
- Neurofibrillary tangles consist of pathologic aggregates of tau protein (115). These pathologic aggregates form in the presence of hyperphosphorylation of the tau protein
- The second pathologic lesion associated with AD is the senile (neuritic) plaque. A neuritic plaque consists of a dense central β-amyloid core with inflammatory cells and dystrophic neurites in its periphery. The β-amyloid core is made up of fragments of the amyloid precursor protein that have aggregated into β-pleated sheets in the extracellular space.
- The ability to identify deposits of abnormal protein (amyloid plaque), which is a cardinal pathologic feature of the disease in living patients, has the ability to revolutionize patient diagnosis and management of AD
- Amyloid imaging is related to imaging of amyloid plaque.
- A large number of ligands have been synthesized and evaluated as candidates for amyloid imaging agents.
- These can be classified into six categories of derivatives: Congo-red, Thioflavine T, stilbene, vinylbenzoxazole, DDNP, and miscellaneous.
- The compound that has been most extensively studied is Pittsburgh Compound B, commonly referred to as PIB .
- PET imaging tracers approved by FDA for amyloid imaging are , florbetaben F18 injection (Neuraceq, Piramal Imaging).,florbetapir (Amyvid, Eli Lilly and Company) and flutemetamol (Vizamyl, GE Healthcare),
AD POSITIVE CASE
NORMAL CASE
REF ---http://www.diagnosticimaging.com/articles/amyloid-imaging-next-frontier-alzheimer%E2%80%99s-care
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