About Sickkids
About SickKids

Giles Santyr , PhD, FCCPM

Research Institute
Senior Scientist
Physiology & Experimental Medicine

University of Toronto
Department of Medical Biophysics, University of Toronto

Phone: 416-813-1394
e-mail: giles.santyr@sickkids.ca
Alternate Contact: Carol Abrahams, Senior Secretary
Alternate Phone: 416-813-8593
Alternate e-mail: carol.abrahams@sickkids.ca

Brief Biography

Dr. Giles Santyr pursued undergraduate studies in physics at Queen’s University in Kingston and received his PhD in Medical Biophysics from the University of Toronto. He went on to work as a research associate and assistant scientist at the University of Wisconsin, where, he earned a National Cancer Institute FIRST award. Moving to Carleton University in Ottawa in 1995, he helped establish the Ottawa Medical Physics Institute and helped pioneered hyperpolarized xenon-129 for lung MRI in rodents. In 2004, he joined the Robarts Research Institute where he held a CIHR Industry-Partnered Chair award for Respiratory Imaging as the Director of the Robarts GE 3T MRI Facility. The Robarts team produced the first xenon-129 human lung images in Canada and the first carbon-13 lung images in the world. Santyr joined The Hospital for Sick Children as a senior scientist in 2013 where he is focusing on MRI approaches to study the lungs of children and young adults.

Santyr is a medical biophysicist working with physicians and engineers to pioneer new techniques for imaging the lungs. Current methods using X-rays or nuclear medicine imaging can help pinpoint disease but involve the use of ionizing radiation, which is a major drawback for assessments over time, especially in vulnerable populations like children and the elderly. Magnetic Resonance Imaging (MRI) is an attractive alternative but is challenging in the lung due to very low signal. New hyperpolarized MRI methods provide an opportunity to boost the signal from the lung and provide unique insight into respiratory function and metabolism without ionizing radiation.

Santyr’s lab is one of a handful in the world that is developing the use of hyperpolarized MRI with helium-3, xenon-129 and carbon-13 to allow the exploration of the lung – from the major airways down to the very smallest alveoli, allowing for safer, earlier and more accurate diagnosis and long-term tracking of disease progression and treatment response. His is the only group internationally using all three nuclei in both animal and human studies of the lung. This research is expected to have a significant impact on the way physicians detect, diagnose and treat lung diseases such as cystic fibrosis, asthma and lung injury.

Research Interests

Santyr’s current research program focuses on hyperpolarized xenon-129 and proton MRI of anatomical and functional lung tissue and cellular biomarkers, specifically: airway and lung parenchymal morphology, ventilation, perfusion, gas exchange and inflammatory cell trafficking in lung diseases afflicting children and animal models of these diseases. Current projects in progress or proposed include:

• technology development for hyperpolarized paediatric lung MRI
• clinical and preclinical xenon-129 MRI of radiation-induced lung injury
• development of MRI approaches for tracking disease progression and therapeutic response in cystic fibrosis and asthma
• use of MRI for understanding lung transplant and stem cell therapies


Fox M, Ouriadov A, Santyr GE. Comparison of hyperpolarized 3He and 129Xe MR imaging for measurement of absolute ventilated lung volume in rats, revised for Magn. Reson. Med. (e-pub ahead of print).

Ouriadov A., Farag A, Kirby M, McCormack DG, Parraga G, Santyr GE. Lung morphometry using hyperpolarized 129Xe apparent diffusion coefficient anisotropy in chronic obstructive pulmonary disease,  Magn. Reson. Med. (e-pub ahead of print).

Thind K, Friesen-Waldner L, Chen A, Ouriadov A, Scholl T, Fox M, Wong E, VanDyk J, Hill R, Hope A, Santyr GE. Detection of radiation-induced lung injury using hyperpolarized 13C magnetic resonance spectroscopy and imaging, Magn. Reson. Med. (e-pub ahead of print).

Kirby M, Svenningsen S, Kanhere N, Owrangi A, Wheatley A, Coxon HO, Santyr GE, Paterson NAM, McCormack DG, Parraga G. Pulmonary ventilation visualized using hyperpolarized helium-3 and xenon-129 magnetic resonance imaging: differences in COPD and relationship to emphysema, J. Appl. Physiol. 114:707-715 (2013).

Boudreau M, Xu X, Santyr GE. Measurement of 129Xe apparent diffusion coefficient anisotropy in an elastase-instilled rat model of emphysema, Magn. Reson. Med. 69: 211-220 (2013).

Fox M, Welch I, Hobson D, Santyr GE. A novel intubation technique for non-invasive longitudinal studies of rat lungs using hyperpolarized 3He MRI, Laboratory Animal 46, 311-317 (2012).

Kirby M, Owrangi A, Svenningsen S, Wheatley A, Farag A, Ouriadov A, Santyr GE, McCormack DG, Parraga G, Hyperpolarized 3He and 129Xe MRI in healthy volunteers and patients with chronic obstructive pulmonary disease, Radiology 265, 600-610 (2012).

Shukla Y, McCormack DG, Patterson N, Wheatley A, Farag A, Santyr GE, Parraga G. Hyperpolarized 129Xe MRI: tolerability in healthy volunteers and subjects with pulmonary disease, Academic Radiology 19, 941-951 (2012).

Couch M, Ouriadov AV, Santyr GE. Regional ventilation mapping of the rat lung using hyperpolarized 129Xe magnetic resonance imaging, Magn. Reson. Med. 68: 1623-1631 (2012).

Xu X, Boudreau M, Ouriadov A, Santyr GE. Mapping of 3He apparent diffusion coefficient anisotropy at sub-millisecond diffusion times in an elastase-instilled rat model of emphysema, Magn. Reson. Med. 67: 1146-1153 (2012).

Mathew L, Kirby M, Farquahar D, Licskai C, Santyr G, Etemad-Rezai R, Parraga G, McCormack DG. Hyperpolarized  3He magnetic resonance imaging of bronchoscopic airway bypass in chronic obstructive pulmonary disease, Can Resp J 19: 41-43 (2012).