Magnetic resonance imaging

Radiopedia - a Growing Resource

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Dr Frank Gaillard is a consultant neuroradiologist at the Royal Melbourne Hospital with interests in brain tumour imaging, multiple sclerosis, neurodegenerative diseases and computer assisted image interpretation.  He is the founder and CEO of Radiopaedia.org, the largest collaborative online  radiology resource, dedicated to effecting global change through open radiology education and resources.  Dr Gaillard works collaboratively with the Neuropsychiatry Unit to review cases and provide teaching. 
 
Dr Gaillard started radiopaedia in 2005, as a way of keeping interesting films while completing his radiology training.  Ten years later, in 2015, Radiopaedia attracted 7 million hits a month from 2 million unique users and represented every country in the world.  As of January 2015, Radiopaedia had a total of 17,660 cases uploaded to the site from radiologists around the world.
"To be able to give radiologists or doctors in third world nations, who don't have the teaching, or the expertise, or the hardware that we do, the ability to see some of these cases and better treat and diagnose their patients is probably what gives me the greatest sense of satisfaction on a day-to-day basis."

ABC News - Link

Subcortial Morphology as a Dementia Biomarker

SUBCORTICAL MORPHOLOGY AS A DEMENTIA BIOMARKER

In collaboration with A/Prof Jeff Looi from the Australian National University, we have conducted a group of studies in various neurodegenerative disorders, and have shown that differing types of illness have relatively unique “shape signatures” that characterise their underlying pathology. These signatures may prove to be unique biomarkers for illness stage, progression over time and response to future illness-modifying therapies.

The two publications characterising these morphological changes in dementia can be found
here and here.

Looi et al. Striatal morphology as a biomarker in neurodegenerative disease.
Mol Psychiatry 2012 May 15. doi: 10.1038/mp.2012.54.

Looi et al.
Frontotemporal dementia as a frontostriatal disorder: neostriatal morphology as a biomarker and structural basis for an endophenotype. Aust NZ J Psychiatry 46: 422-434, 2012.

Brain Shape Analysis May Differentiate Alzheimer's from FTD

BRAIN SHAPE ANALYSIS DIFFERENTIATES ALZHEIMER’S DISEASE FROM FRONTOTEMPORAL DEMENTIA

A/Prof Mark Walterfang and Dr Dennis Velakoulis, with colleagues from ANU and the Karolinska Institute in Sweden, have shown how analysis of the shape of the hippocampus, one of the key brain regions involved in memory, can differentiate Alzheimer’s disease (AD) from another key type of dementia, fronto-temporal dementia (FTD).

Dr Walterfang undertook computerised shape analysis techniques on magnetic resonance imaging (MRI) scans to demonstrate that the head of the hippocampus is preferentially affected in FTD, whereas it is relatively spared in AD, which tends to affect the rest of the hippocampal structure.

The paper can be found
here.

Lindberg et al. Hippocampal shape analysis in Alzheimer’s disease and frontotemporal dementia subtypes. J Alzheimers Dis 30: 355-365, 2012.

Pontine to midbrain ratio: useful in NPC

THE PONTINE TO MIDBRAIN RATIO: USEFUL IN NPC, TOO

Niemann-Pick type C (NPC) disease is a rare autosomal recessive disorder that presents in adults with cognitive and motor disturbance, psychosis, and highly prominent vertical gaze palsy. We aimed to see if a validated measure in other disorders that demonstrate midbrain atrophy and have vertical gaze impairments was also useful in NPC. By examining a group of adult NPC patients and a larger group of matched controls, we showed that the pontine to midbrain ratio (PMR) - which, when elevated, reflects midbrain atrophy and consequent impairment of saccadic burst neurons that control eye gaze. We showed that this ratio is increased in NPC, although not to the same degree seen in other disorders such as progressive supranuclear palsy. However, this ratio was highly correlated to duration of illness and a range of measures of illness severity, including cognitive and ocular-motor functioning. The PMR may thus be a useful diagnostic and illness marker in NPC.

The paper can be found here.
Walterfang et al.
Pontine-to-midbrain ratio indexes ocular-motor function and illness stage in adult Niemann–Pick disease type C. Eur J Neurol, in press 2011.

Brain Changes in Adult NPC


Utilising methodology developed by Professor David Reutens, now at the Queensland Brian Institute, Dr Amanda Wood, from the University of Birmingham, and Drs Larry Abel and Elizabeth Bowman from the University of Melbourne’s Department of Optometry and Vision Sciences, we followed up our landmark MRI study in adults with Niemann-Pick disease type C (NPC) with a shape analysis of the corpus callosum (CC), the brain’s largest white matter fibre bundle, which connects the brain’s two hemispheres. This study demonstrated that the CC in NPC is globally thinned, but disproportionately thinned in regions similar to those seen in established schizophrenia, and may go some way to explaining the increased rate of psychosis in adults with NPC.

This paper can be found here.
Walterfang et al. Size and shape of the corpus callosum in adult Niemann-Pick type C reflects state and trait illness variables. American Journal of Neuroradiology 32: 1340-1346, 2011.