Advanced Imaging Lab

Richard Aviv profile picture

Contact Information

Richard Aviv, MBChB, FRCR (UK), FRCPC, dABR
613 737-8899 ext 73040
raviv@toh.ca

What We Do

Research Foci:

Advanced computed tomography and magnetic resonance imaging application to neurological disease
Artificial Intelligence applications 
3D printing

Selected Publications

1. Aviv RI, Huynh T, Huang Y, Ramsay D, Van Slyke P, Dumont D, Asmah P, Alkins R, Liu R, Hynynen K. An in vivo, MRI-integrated real-time model of active contrast extravasation in acute intracerebral hemorrhage. AJNR Am J Neuroradiol. 2014 Sep;35(9):1693-9. Senior Responsible Author.

First animal model of contrast extravasation in ICH. The model provides the basis for testing of existing and novel theraputic interventions in ICH and allows for the first study of real-time in vivo modeling of ICH expansion.

2. Eilaghi A, d’Esterre CD, Lee TY, Jakubovic R, Brooks J, Liu RT, Zhang L, Swartz RH, Aviv RI. Toward patient-tailored perfusion thresholds for prediction of stroke outcome. AJNR Am J Neuroradiol. 2014 Mar;35(3):472-7. Senior Responsible Author.

This paper provided a proof of principle that baseline thresholds that predict infarct outcome can be modulated by multiparametric factors such as time to presentation, whether rTPA treatment is being considered etc to improve the predictive ability of a stroke threshold model. This is the first publication to show feasibility of this concept.

3. Demchuk AM, Dowlatshahi D, Rodriguez-Luna D, Molina CA, Blas YS, Dzialowski I, Kobayashi A, Boulanger JM, Lum C, Gubitz G, Padma V, Roy J, Kase CS, Kosior J, Bhatia R, Tymchuk S, Subramaniam S, Gladstone DJ, Hill MD, Aviv RI, PREDICT/Sunnybrook ICH CTA study group. Prediction of haematoma growth and outcome in patients with intracerebral haemorrhage using the CT-angiography spot sign (PREDICT): a prospective observational study. Lancet Neurol. 2012 Apr;11(4):307-14. Senior Responsible Author.

This is the first prospective multicenter study validating the predictive ability of the CTA Spot Sign and demonstrating feasibility for multicenter CT angiographic acquisition in ICH.

4. 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. 2012 Oct;33(9):1779-85. Epub 2012 Apr 26. Principal Author.
First paper to evaluate cortical perfusion and link it to cortical integrity and cognition. We demonstrated robust perfusion deficits within structural regions consistent with impairment. This work has served as the basis for subsequent studies comparing other MRI techniques such as ASL with the bookend perfusion method and validation of bookend perfusion as a surrogate biomarker of cortical integrity.

5. Wada R, Aviv RI, Fox AJ, Sahlas DJ, Gladstone DJ, Tomlinson G, Symons SP. CT angiography “spot sign” predicts hematoma expansion in acute intracerebral hemorrhage. Stroke. 2007 Apr;38(4):1257-62. Senior Responsible Author.

This paper describes a novel CTA finding that has been verified by a number of subsequent papers to predict primary hematoma expansion. This and related papers rekindled interest in recombinant factor VIIa after a recent phase III study using Factor VIIa was negative for clinical outcome. There is great hope amongst the Neurology community worldwide that the Spot sign could be a marker of increased risk for hematoma expansion. This has led to a number of studies being undertaken both National and international. A prospective multicenter study, PREDICT, led by Andrew Demchuk from Calgary was subsequently undertaken to validate the sign. My publication of these papers has resulted in my involvement in PREDICT as the study Neuroradiologist. The publications also shaped a prospective intervention study in ICH, STOP-IT. Data from these papers was used to formulate the grant proposal and model the sample size predictions. This study was funded by NINDS/SPOTRIAS and is underway. The study will investigate whether the spot sign can be used as a marker for intervention with rFVIIa. I am on the steering committee for this study and created the educational website for training of physicians in spot sign recognition. While STOP-IT is a US study, two Canadian centres, Sunnybrook and Calgary are also participating. However to increase Canadian participation David Gladstone, and I were successful at obtaining funding for a parallel study here in Canada, SPOTLIGHT. The proposal is modeled on STOP-IT and will increase the sample size and study power while bringing additional value by including neurocognitive outcomes.

Meet the Advanced Imaging Lab