Cognitive compensation in super-agers
Around the world researchers are working to better understand cognitive ageing, to help older people live healthy, high quality lives for longer. We apply MRI and simultaneous MR/PET to quantify the neural basis of cognitive resilience, which conveys a protective effect against age-related cognitive decline.
Vascular and iron imaging in healthy ageing
The oxygen content of blood vessels is critical to energy production in the brain, and is influenced by heart and lung health, as well as blood and blood vessels. Iron on the other hand is an indicator of oxidative damage in the brain, and accumulates around sights of inflammation. We are using MRI to investigate these aspects of brain health and to identify the early stages of cognitive decline.
The neural bases of parenthood
Winnie Orchard, Sharna Jamadar, Phillip Ward, Disha Sasan
During and after pregnancy, the brain undergoes plastic changes that may be neuroprotective. Parenthood-related changes are apparent in both women and men. Our work shows that these changes are preserved across the lifespan, and may also explain some of the idiosyncratic post-pregnancy symptoms, such as the continued experience of foetal kicks after the end of the pregnancy.
Development of simultaneous functional MRI – functional PET imaging techniques
Sharna Jamadar, Phillip Ward
Simultaneous MRI-PET imaging is a nascent technology that can simultaneously provide high-resolution structural, functional and metabolic images. We are developing high-temporal resolution [18F]-fluorodeoxyglucose PET (FDG-PET) imaging that can simultaneously provide blood oxygenation level dependent fMRI (BOLD-fMRI) contrast.
Radiotracer Administration for High Temporal Resolution Positron Emission Tomography of the Human Brain: Application to FDG-fPET
Sharna Jamadar, Phillip Ward, Alexandra Carey, Richard McIntyre, Linden Parkes, Disha Sasan, John Fallon, Winnie Orchard
Functional positron emission tomography (fPET) provides a method to track molecular targets in the human brain. With a radioactively-labelled glucose analogue, 18F-fluordeoxyglucose (FDG-fPET), it is now possible to measure the dynamics of glucose metabolism with temporal resolutions approaching those of functional magnetic resonance imaging (fMRI). This direct measure of glucose uptake has enormous potential for understanding normal and abnormal brain function and probing the effects of metabolic and neurodegenerative diseases. Further, new advances in hybrid MR-PET hardware make it possible to capture fluctuations in glucose and blood oxygenation simultaneously using fMRI and FDG-fPET.
The temporal resolution and signal-to-noise of the FDG-fPET images is critically dependent upon the administration of the radiotracer. This work presents two alternative continuous infusion protocols and compares them to a traditional bolus approach. It presents a method for acquiring blood samples, time-locking PET, MRI, experimental stimulus, and administering the non-traditional tracer delivery. Using a visual stimulus, the protocol results show cortical maps of the glucose-response to external stimuli on an individual level with a temporal resolution of 16 s.
Read the full research paper on JoVE and watch the JoVE video below.