A PET/CT scan is a powerful diagnostic examination which combines information about how the brain is working (PET) with structural information i.e. what the brain looks like, (CT) in one examination. There are two common types of PET/CT scans for the brain – an FDG scan which highlights brain metabolism and amyloid scans which record the amount of a special protein in the brain called beta amyloid.
The formation of ‘plaques’ of beta amyloid protein in the brain is one of the hallmarks of Alzheimer’s disease (AD). Plaques are collections of beta amyloid protein that abnormally clump together in AD patients.
Amyloid PET imaging detects the beta-amyloid protein in both the plaques in the brain and in the blood vessels supplying the brain. It appears that beta-amyloid plays an important role in the disease because plaques are found in all patients with AD.
A positive amyloid PET scan in itself is not definitive for Alzheimer’s disease however this test is a diagnostic tool to determine whether or not there is beta-amyloid in the brain. This helps increase the clinical certainty of a diagnosis.
The types of patients who might be considered for an Amyloid PET/CT scan are patients who
- have a family history of Alzheimer’s disease
- a history of progressive unexplained mild cognitive impairment
- patients with progressive dementia and
- atypical early age of onset <65 of symptoms and where Alzheimer’s disease is a possible diagnosis but the diagnosis remains uncertain upon comprehensive evaluation
The first two clinical Amyloid PET/CT patients in Perth will be scanned today, Wednesday 31st May, at Perth Radiological Clinic’s Oceanic Molecular PET/CT centre located at Hollywood Hospital in Nedlands.
The scan involves an injection of a very small amount of a radioactive tracer into a vein in the arm. There is a delay between the injection and the scan of 90 minutes while the tracer travels from the blood stream into the brain, after which the scan will commence. The scan takes approximately 25 minutes. The images are reviewed by a Nuclear Physician or Radiologist who has special training in amyloid imaging and extensive experience with brain PET/CT.
Oceanic Molecular at Hollywood has been involved with PET/CT studies for Alzheimer’s research in conjunction with The Australian Alzheimer’s Research Foundation (formerly the McCusker Foundation for Alzheimer’s Disease Research) since 2010.
Amyloid PET/CT scans have been offered to the public outside of research in the Eastern States of Australia but this is the first time that patients in WA will have access to this scan in the clinical non-research setting.