Authors: Alice Weatherston
Richard Aviv has been widely involved with research into the CTA Spot Sign for intracerebral hemorrhages as well as the imaging of Multiple Sclerosis. We found out more about his career to date and where he hopes to see future research progress within these fields.
Can you tell us a little about your background and your career to date?
I initially carried out my undergraduate degree at in the Faculty of Medicine at the University of Cape Town (South Africa). Following this I pursued postgraduate medical training in the UK at St James’s University Hospital (Leeds) for 3 years. I began radiology training in 1997 at the Royal Free Hospital (London, UK) and completed specialist neuroradiology training at the Royal Free Hospital, the National Institute for Neurology (London, UK), Oxford Royal Infirmary (UK) and then in Toronto (ON, Canada) at the Hospital for Sick Children and Sunnybrook Health Sciences Center, where I am now appointed as a Professor in Medical Imaging in the Division of Neuroradiology. I am also an Affiliate scientist at the Sunnybrook Research Institute and the Associate Vice Chair of Research at University of Toronto, Department of Medical Imaging (ON, Canada).
At present, what are the main focuses for research in your team?
My research interests are broad including intracerebral hemorrhage, advanced stroke imaging and multiple sclerosis (MS). I am particularly interested in the link between gray matter perfusion abnormality and cognition in MS.
You have been instrumental in the development of the predictive marker of hemorrhagic strokes, the CTA spot sign. What impact do you foresee this having on the development of alternative therapeutics?
The CTA spot sign has caught the imagination and aspirations of neurologists around the world who believe that it represents a significant step towards the selective management of patients with intracranial hemorrhage (ICH). This is particularly important given the lack of clinical improvement despite volume reduction within a Phase III study of recombinant Factor VIIa . The Spot Sign has effectively reopened the potential for urgent therapeutic intervention in ICH patients, but this time selectively applied. Three prospective randomized studies (STOP-IT, SPOTLIGHT and STOP-AUST) are utilizing the CTA spot sign as a surrogate for patient selection in trials of hemostatic therapy. In addition to clinical studies, we have recently completed the first animal model of Spot positive ICH using MRI integrated ultrasound (AJNR 2014) and have for the first time demonstrated an in vivo model of ICH expansion. This work was featured at the Co-Chairs’ award for impact session at the Canadian Stroke Congress in 2013. It is my hope that these animal models will inform ongoing clinical studies by permitting the testing of existing and new thrombotic therapies.
You also have a strong interest in multiple sclerosis and have been exploring the vascular etiology of the disease. So far, what indications have these studies given?
Advanced MRI such as perfusion imaging facilitates a greater understanding of the underlying pathophysiology of MS. My recent study  was the first to examine the link between cortical perfusion and cognition using a novel quantitative MRI perfusion protocol. We demonstrated regional perfusion reduction in the presence of cognitive impairment after controlling for confounding factors. The results were recently validated in relapsing-remitting MS, having previously been shown in secondary progressive MS, suggesting a common biomarker of disease severity in both MS subtypes.
What do you think is currently the biggest challenge facing research in the fields of both stroke and multiple sclerosis?
Challenges in each area are different. Stroke research is being held back by heterogeneity of opinion on advanced techniques such as perfusion CT or MR and their role in acute stroke. The lack of agreement spans all steps from acquisition to post-processing and display. The biggest challenges in MS imaging revolves around the availability of MRI sequences with sufficiently high spatial resolution to image the cortex while maintaining realistic scan times. Imaging focus needs to broaden to include multimetric clinical and imaging parameters in predictive models that may guide therapeutic intervention and provide measurable parameters to monitor therapeutic efficacy.
In what area do you think your research may have the most impact over the next 10 years?
It is my hope that we will develop a predictive biomarker of cortical disease severity in MS that will assist therapeutic studies to determine efficacy.
1. Mayer SA, Brun NC, Begtrup K, Broderick J, Davis S, Diringer MN, Skolnick BE, Steiner T. Efficacy and safety of recombinant activated factor vii for acute intracerebral hemorrhage. N Engl J Med. 358, 2127-2137 (2008).
2. Aviv RI, Francis PL, Tenenbein R, O’Connor P, Zhang L, Eilaghi A, Lee L, Carroll TJ, Mouannes-Srour J, Feinstein A. Decreased frontal lobe gray matter perfusion in cognitively impaired patients with secondary-progressive multiple sclerosis detected by the bookend technique. AJNR Am J Neuroradiol. 33, 1779-1785 (2012).
The opinions expressed in this interview are those of the interviewee and do not necessarily reflect the views of Neurology Central or Future Science Group