Pablo Rusjan

Pablo Rusjan is a research scientist at the Research Imaging Centre at the Centre for Addiction and Mental Health (CAMH). Dr. Rusjan has a background in theoretical physical chemistry and his research focused on the quantitation of proteins in the human brain using positron emission tomography (PET). This comprises a spectrum of interests of each step involved in PET, including the initial use of novel radioligands in-vivo, the acquisition and post-processing of blood and imaging data, understanding the pharmacokinetics of each radioligand, the development and implementation of novel quantitative analysis, and the application to clinical studies to explore disease progression and treatment options.

Dr. Rusjan received his undergraduate training in physics in the University of Buenos Aires. He did a MSc equivalent thesis and a PhD thesis on chemical reactivity in fluid media using computer simulations at the National Atomic Energy Commission Argentina (CNEA by its Spanish acronym). After a specialization in computer vision and a professional experience using computer models to evaluate the financial feasibility of transportation megaprojects, he immigrated to Canada in 2003 where he joined the University of Toronto. His initial work involved the development of a software for PET image analysis (ROMI), which is currently being used at CAMH, and in other centers across the world.

Research Synopsis

Positron emission tomography (PET) provides a unique tool to study the biochemistry of the human brain in vivo. In psychiatry, PET can be used to find biomarkers of pathology and test the effect of therapeutic drugs. Each protein to be studied (eg. neuroreceptor, enzyme) requires the development a new radioligand and each new radioligand requires a proper method for quantification. The specific goal of my research is the development of quantitative analysis methods for the implementation and validation of new PET radiotracers. The optimal quantification comprises the use of proper and reliable image analysis techniques, pharmacokinetic approaches, numerical analysis and clinical experiments to validate the models. These include:
• Pharmacokinetic modelling of PET data.
• Delay and dispersion related to arterial line sampling and acquisition with the automatic blood sample system.
• Less invasive, simplified methods for PET quantification.
• Motion Correction of PET images.
• Automated techniques for ROI delineation and PET image analysis.
• Partial volume effect correction algorithms for PET images.
• Parametric (voxelwise) images generation.