Brain PET Scan for — Dementia and Memory Loss

The most common type of brain PET scan uses a glucose-based tracer called FDG. Areas of the brain that are less active than expected take up less glucose, and those regions appear cooler on the scan image. Certain patterns of reduced activity help your neurologist understand what may be causing memory changes.

A different type, amyloid PET, detects amyloid protein deposits rather than measuring activity levels. Your neurologist will have chosen one based on the clinical question they are trying to answer. Both types are reported by a nuclear medicine specialist and sent directly to your referring neurologist.

The scan cannot give a yes-or-no diagnosis on its own. It produces a pattern — of metabolic activity, or of amyloid deposition — that your neurologist weighs alongside your symptoms, cognitive testing, and other investigations.

A pattern associated with Alzheimer's adds weight to a clinical diagnosis but does not confirm it in isolation. A broadly normal scan does not rule out early disease if your neurologist's assessment suggests otherwise. The scan is a tool that informs clinical judgement — it is not a verdict, and there are no guarantees.

PET technology is the same whether it is used to study a tumour or to measure brain function. The scanner does not know why you are there. Being referred to a PET centre associated with an oncology network does not mean cancer is suspected — this is not a cancer indication.

CION coordinates PET scans for neurological brain studies through partner imaging centres. The scan is reported and returned to your referring neurologist. Clinical responsibility for your diagnosis and care remains with your referring specialist throughout; CION's role is to arrange and perform the scan.