Dr Gill Farrar
Global Medical Leader Neurology, GE HealthCare
Dr Farrar liaises with physicians responsible for referring and scanning patients, keeping them abreast of new trends and image analysis methods and supporting their research efforts.
How has your role evolved in recent years?
The trend is towards using software tools to enhance image interpretation as well as collaborating with consortiums such as AMYPAD In Alzheimer’s disease and PPMI (sponsored by MJ Fox Foundation) in Parkinson’s disease.
How do neurology imaging agents work?
Molecular imaging tracers bind to brain pathology (proteins that are abnormally present or contain structural deficits not present in a healthy person) and are labelled with a short-lived radioisotope. Once administered, the radioisotope decays and emits energy or particles detected by a camera, and the image is then reconstructed, showing the absence or presence of pathology.
The scan adds a huge amount of
weight to the final clinical diagnosis.
The tracer Vizamyl targets amyloid, a seminal feature of Alzheimer’s disease (AD), and is seen at an early stage of the disease. In Parkinson’s disease (PD), the tracer DaTSCAN detects the loss of dopaminergic neurones. DaTSCAN differentiates both PD from essential tremor; and dementia with Lewy bodies from AD.
Both tracers are used in combination with clinical work-up and provide adjunctive information about the pathological status of the patient.
What value does the scan bring to the patient?
In routine clinical work-up, the signs and symptoms of these neurological diseases are quite difficult to tease apart. We are directly imaging in the brain the neuropathology associated with that disease. The scan adds a huge amount of weight to the final clinical diagnosis. Once a diagnosis has been established, the patient and their families — with the physician — can plan for the future.
How might these tracers be used in the future?
For the Vizamyl agent, the advent of new anti-amyloid therapies could potentially designate a patient as amyloid-positive and hence receive and possibly monitor therapy impact. For DaTSCAN, the current focus is on early disease detection and, in combination with software tools, could aid a more timely diagnosis.