Acute Stroke: Imaging The Ischaemic Penumbra With Perfusion CT
Funder
National Health and Medical Research Council
Funding Amount
$243,000.00
Summary
The burden of stroke is large. Clot-dissolving medication (thrombolysis) may dramatically improve the outcome of many patients with severe stroke by unblocking the affected brain artery. However, very few patients receive this medication, as the current approval is restricted to treatment within 3 hours of stroke onset. The major aim of thrombolysis is to rescue brain tissue with reduced blood flow (the ischaemic penumbra) from becoming irreversibly damaged (infarcted). The penumbra progressivel ....The burden of stroke is large. Clot-dissolving medication (thrombolysis) may dramatically improve the outcome of many patients with severe stroke by unblocking the affected brain artery. However, very few patients receive this medication, as the current approval is restricted to treatment within 3 hours of stroke onset. The major aim of thrombolysis is to rescue brain tissue with reduced blood flow (the ischaemic penumbra) from becoming irreversibly damaged (infarcted). The penumbra progressively becomes infarcted over the next 48 hours if blood flow is not restored by the blood clot in the brain artery being dissolved. Penumbral brain tissue cannot be identified with clinical assessment or standard CT scanning. New generation CT scanners are capable of assessing brain blood flow. Perfusion CT imaging (CTP) is well tolerated and time-efficient, and can be integrated into the brain CT scanning process performed on all stroke patients. Preliminary evidence suggests that CTP can distinguish between tissue that represents the ischaemic penumbra, and tissue that is already permanently injured. This project aims to validate the use of CTP in imaging the ischaemic penumbra. This will be based on testing the accuracy of CTP tissue signatures of the penumbra in predicting clinical outcome and final stroke size. This is the only national collaborative study planned worldwide for this relatively new but increasingly accessible imaging technique. The ability to rapidly identify under-perfused but still viable brain with CTP would add new and exciting management options to the routine emergency assessment of stroke patients. The results of this unique study could have a significant impact on the management of acute stroke worldwide. If validated, it is anticipated that CTP would be widely used to improve patient selection for stroke thrombolysis, especially in safely extending the time window so that a greater number of patients can be treated with better outcomes.Read moreRead less
Improving The Assessment Of Brain Tumour Treatment Outcome Using 18F-FDOPA PET-MRI Fusion
Funder
National Health and Medical Research Council
Funding Amount
$660,666.00
Summary
The mortality rate within the first year of diagnosis for high-grade brain tumours is approximately 80%. A major factor contributing to poor outcome measures is the limitation of current neuroimaging techniques. In a novel approach we propose to combine the information available from MRI and PET images to better define the extent of the tumour and provide markers of early treatment response. This improved diagnostic information should improve survival rates.
Episodic Memory Dysfunction As A Basis For Auditory Hallucinations In Schizophrenia
Funder
National Health and Medical Research Council
Funding Amount
$278,517.00
Summary
Auditory hallucinations (AHs) occur frequently in people who suffer from schizophrenia. This symptom usually involves hearing voices that the hallucinator firmly believes originate from other people. The voices are often intrusive, abusive and persecutory. They are a source of significant stress and may result in self harm or harm to others. Our investigations will attempt to provide experimental support for the theory that AHs represent a misremembering of voices which were heard in the past. W ....Auditory hallucinations (AHs) occur frequently in people who suffer from schizophrenia. This symptom usually involves hearing voices that the hallucinator firmly believes originate from other people. The voices are often intrusive, abusive and persecutory. They are a source of significant stress and may result in self harm or harm to others. Our investigations will attempt to provide experimental support for the theory that AHs represent a misremembering of voices which were heard in the past. We will do this by attempting to characterise specific problems that hallucinators have in identifying when they heard verbal fragments and who said them. We plan to conduct our investigations at five levels. First, we will determine how accurate hallucinators' memories are for context by the use of special neuropsychological tests. Second, we will find out if hallucinators form more false memories than comparison subjects using a test in which such incorrect recollections occur commonly. Third, we will determine if hallucinators have a tendency to reconstruct the characteristics of false verbal memories in the same way that they reconstruct the characteristics of their hallucinations. Fourth, we will attempt to suppress these false verbal memories and finally, we will characterise those brain regions which are activated during true and false memory formation by using blood flow analysis technology in order to identify networks of brain activity which preferentially malfunction in hallucinating patients. This study provides the prospect of adding substantially to our understanding of the mechanisms underlying auditory hallucinations and to lead to the development of new cognitively-based treatments for the symptom.Read moreRead less
Abeta Amyloid Imaging In Neurodegenerative Disorders With A Novel 18F Radiotracer
Funder
National Health and Medical Research Council
Funding Amount
$1,084,266.00
Summary
Alzheimer's disease is the most common age-related neurodegenerative disease, and the most common cause of dementia. It is estimated that 212,000 Australians suffer from dementia and this will rise to approximately 730,000 by 2050. Currently there are no definitive diagnostic methods for AD. The research proposed in this application describes the evaluation of a new imaging radiotracer that would be suitable for widespread non-invasive diagnosis of AD.
A new scan called PiB PET shows the build up of amyloid protein deposits in the brain in all patients with Alzheimer's disease (AD) but also in 30% of normal elderly persons. This study will track the build up of amyloid and clinical progress in 280 elderly Australians to confirm that this scan can detect AD before symptoms and investigate factors that influence this build up and its damaging effects on memory and thinking. Early detection of Alzheimer's disease will assist accurate diagnosis an ....A new scan called PiB PET shows the build up of amyloid protein deposits in the brain in all patients with Alzheimer's disease (AD) but also in 30% of normal elderly persons. This study will track the build up of amyloid and clinical progress in 280 elderly Australians to confirm that this scan can detect AD before symptoms and investigate factors that influence this build up and its damaging effects on memory and thinking. Early detection of Alzheimer's disease will assist accurate diagnosis and the development of treatment.Read moreRead less
Airway Wall Thickness And Heterogeneity Are Key Determinants Of Asthmatic Airway Function.
Funder
National Health and Medical Research Council
Funding Amount
$207,509.00
Summary
Asthma is a common disease which is typified by excessive narrowing of the airways in response to stimuli that are trivial to non-asthmatic individuals. However, little is known about what causes asthmatic airways to be able to narrow so excessively. In this study, we will be looking at the importance of thickening of the airway walls in relation to excessive airway narrowing in asthmatics. We will also look to see how patchy the airway narrowing is in asthmatics and how this relates to excessiv ....Asthma is a common disease which is typified by excessive narrowing of the airways in response to stimuli that are trivial to non-asthmatic individuals. However, little is known about what causes asthmatic airways to be able to narrow so excessively. In this study, we will be looking at the importance of thickening of the airway walls in relation to excessive airway narrowing in asthmatics. We will also look to see how patchy the airway narrowing is in asthmatics and how this relates to excessive airway narrowing that occurs in severe asthmatic attacks. We will therefore be studying asthmatics of varying degrees of disease severity as well as those admitted to hospital because of acute severe attacks of asthma, and comparing them with a group of non-asthmatic subjects.Read moreRead less