Principal Investigators

Colleen Bailey, PhD


PhD, 2012, Medical Biophysics, University of Toronto, Toronto, ON, Canada
BSc, 2005, Biophysics, University of Guelph, Guelph, ON, Canada

Appointments and Affiliations

•Scientist, Physical SciencesOdette Cancer Research Program, Sunnybrook Research Institute

•Adjunct Professor, Department of Physics, Faculty of Science, Ryerson University

•Assistant Professor, Department of Medical Biophysics, Faculty of Medicine, University of Toronto

•Senior Research Associate

Research Foci:

Dr. Bailey’s studies focus on developing magnetic resonance imaging (MRI) biomarkers that can be used as predictors or early indicators of cancer therapy response. Her team uses quantitative MRI methods – including diffusion MRI and relaxation – and mathematical models of biological systems to examine tissue features such as cells, vasculature, extracellular space and cell membrane permeability. The work includes basic research on cancer cell cultures as well as clinical research in patients to develop and validate biomarkers for characterizing cancer and aiding in treatment decision-making.

Research Summary:

The focus of Dr. Bailey’s research is the development of non-invasive MRI methods to monitor the efficacy of radiation treatment in cancer. This work includes analysis of diffusion MRI signal with mathematical models that describe the vascular, cellular and extracellular signal components. The aim is to characterize tumours with more biologically relevant parameters and improve diffusion-based MRI biomarkers. This work has been used to characterize prostate and breast cancers as well as bone metastases. It includes histological validation using patient-specific 3-D-printed molds and image registration.

Dr. Bailey has also adapted conventional dynamic contrast-enhanced MRI to measure water exchange across the cell membrane, a feature related to permeability changes during cell death. The water exchange parameter distinguishes brain metastases that respond to radiotherapy from those that do not one week post-treatment, thereby allowing therapies to be adapted.

Furthermore, Dr. Bailey’s work has involved magnetization transfer studies of apoptotic cell death and the combination of MRI features with other modalities, such as microbubble ultrasound. The magnetic resonance linear accelerator at Sunnybrook, which integrates a linear accelerator for cancer treatment with a 1.5 T MRI for treatment planning and monitoring, provides new opportunities for monitoring treatment response with MRI.




  1. Tan JL, Djayakarsana D, Wang H, Chan RW, Bailey C, Lau AZ. Deuterium MRS of early treatment-induced changes in tumour lactate in vitro. NMR Biomed. 2021 Aug 18:e4599. doi: 10.1002/nbm.4599. Epub ahead of print. PMID: 34405471.


  1. Bailey C, Bourne RM, Siow B, Johnston EW, Brizmohun Appayya M, Pye H, Heavey S, Mertzanidou T, Whitaker H, Freeman A, Patel D, Shaw GL, Sridhar A, Hawkes DJ, Punwani S, Alexander DC, Panagiotaki E. VERDICT MRI validation in fresh and fixed prostate specimens using patient-specific moulds for histological and MR alignment. NMR Biomed. 2019 May;32(5):e4073. doi: 10.1002/nbm.4073. Epub 2019 Feb 19. PubMed PMID: 30779863; PubMed Central PMCID: PMC6519204.


  1. Bailey C, Collins DJ, Tunariu N, Orton MR, Morgan VA, Feiweier T, Hawkes DJ, Leach MO, Alexander DC, Panagiotaki E. Microstructure Characterization of Bone Metastases from Prostate Cancer with Diffusion MRI: Preliminary Findings. Front Oncol. 2018 Feb 16;8:26. doi: 10.3389/fonc.2018.00026. eCollection 2018. PubMed PMID: 29503808; PubMed Central PMCID: PMC5820304.
  2. Hudson JM, Bailey C, Atri M, Stanisz G, Milot L, Williams R, Kiss A, Burns PN,Bjarnason GA. The prognostic and predictive value of vascular response parameters measured by dynamic contrast-enhanced-CT, -MRI and -US in patients with metastatic renal cell carcinoma receiving sunitinib. Eur Radiol. 2018 Jun;28(6):2281-2290. doi: 10.1007/s00330-017-5220-2. Epub 2018 Jan 30. PubMed PMID: 29383520.
  3. Bourne RM, Bailey C, Johnston EW, Pye H, Heavey S, Whitaker H, Siow B, Freeman A, Shaw GL, Sridhar A, Mertzanidou T, Hawkes DJ, Alexander DC, Punwani S, Panagiotaki E. Apparatus for Histological Validation of In Vivo and Ex Vivo Magnetic Resonance Imaging of the Human Prostate. Front Oncol. 2017 Mar 24;7:47. doi: 10.3389/fonc.2017.00047. eCollection 2017. PubMed PMID: 28393049; PubMed Central PMCID: PMC5364138.
  4. Mehrabian H, Desmond KL, Chavez S, Bailey C, Rola R, Sahgal A, Czarnota GJ, Soliman H, Martel AL, Stanisz GJ. Water Exchange Rate Constant as a Biomarker of Treatment Efficacy in Patients With Brain Metastases Undergoing Stereotactic Radiosurgery. Int J Radiat Oncol Biol Phys. 2017 May 1;98(1):47-55. doi: 10.1016/j.ijrobp.2017.01.016. Epub 2017 Jan 10. PubMed PMID: 28258890.
  5. Bailey C, Siow B, Panagiotaki E, Hipwell JH, Mertzanidou T, Owen J, Gazinska P, Pinder SE, Alexander DC, Hawkes DJ. Microstructural models for diffusion MRI in breast cancer and surrounding stroma: an ex vivo study. NMR Biomed. 2017 Feb;30(2). doi: 10.1002/nbm.3679. Epub 2016 Dec 21. PubMed PMID: 28000292; PubMed Central PMCID: PMC5244665.