Ralph Baddour

Ph.D. Candidate, Medical Physics & Imaging

M.Sc. (Medical Biophysics) University of Toronto

B.E.Sc. (Electrical Engineering, Management Option) University of Western Ontario

B.Sc. (Computer Science) University of Western Ontario

Research Interests

It has been previously shown that high frequency ultrasound (20 - 100 MHz) can be used to detect cellular structure changes in biological tissues and cell ensembles. In particular, the changes seen during apoptotic cell death are very striking (Kolios MC, Czarnota GJ, et al. (2002). "Ultrasonic spectral parameter characterization of apoptosis." Ultrasound in Medicine and Biology 28(5): 589-597). Imaging changes in cell structure has implications in a broad range of fields, from cancer treatment monitoring to organ transplantation. However, the changes seen in the backscattered ultrasound intensity and frequency spectrum are not fully understood. My research work includes:

Investigating the physical mechanisms involved in the scattering of acoustic waves by individual cells.

Developing and exploring a model for studying how the changes in the sizes, spatial distribution, and mechanical properties of cells (and their intra-cellular components) affect the resulting backscattering of high frequency ultrasound by an ensemble of cells.

Publications (which are related to Ph.D. work)

Journal articles:

Baddour RE, Dadani FN, Kolios MC, Bisland SK. High-frequency ultrasound assessment of antimicrobial photodynamic therapy in vitro. Journal of Biological Physics. Feb 2007, 33(0): 61-66.

Taggart L, Baddour RE, Giles A, Czarnota GJ, Kolios MC. Ultrasonic characterization of viable whole cells and isolated nuclei. Ultrasound in Medicine and Biology. Mar 2007, 33(3): 389-401.

Baddour RE, Kolios MC. The fluid and elastic nature of nucleated cells: Implications from the cellular backscatter response. Journal of the Acoustical Society of America. Jan 2007, 121(1): EL16-EL22.

Baddour RE, Kolios MC. The effect of packing order on ultrasound backscatter from cells at different volume fractions. Canadian Acoustics Journal. Sep 2005, 33(3): 100-101.

Baddour RE, Sherar MD, Hunt JW, Czarnota GJ, Kolios MC. High frequency ultrasound scattering from microspheres and single cells. Journal of the Acoustical Society of America. Feb 2005, 117(2): 934-943.

Proceedings papers:

Baddour RE, Kolios MC. Investigating the effect of cell size on the backscatter from suspensions of varying volume fractions. Proceedings of the IEEE Ultrasonics Symposium, Sep 2006: 637-640.

Baddour RE, Kolios MC. The effect of volume fraction on the backscatter from nucleated cells at high frequencies. Proceedings of the IEEE Ultrasonics Symposium, Sep 2005: 1672-1674.

Tunis AS, Baddour RE, Czarnota GJ, Giles A, Worthington AE, Sherar MD, Kolios MC. Using high frequency ultrasound envelope statistics to determine scatterer number density in dilute cell solutions. Proceedings of the IEEE Ultrasonics Symposium, Sep 2005: 878-881.

Kolios MC, Taggart L, Baddour RE, Foster FS, Hunt JW, Czarnota GJ, Sherar MD. An investigagion of backscatter power spectra from cells, cell pellets and microspheres. Proceedings of the IEEE Ultrasonics Symposium, Oct 2003: 752-757.

Baddour RE, Sherar MD, Czarnota GJ, Hunt JW, Taggart L, Giles A, Farnoud NR, Kolios MC. High frequency ultrasound imaging of changes in cell structure including apoptosis. Proceedings of the IEEE Ultrasonics Symposium, Oct 2002: 1598-1603.

Published abstracts:

Baddour R, Kolios M, Sherar M. Modelling high frequency ultrasound scattering of cellular ensembles to deduce the apoptotic index. Ultrasound in Medicine and Biology. May 2003, 29(5): S19-S20.

Non-refereed publications:

Baddour RE. High frequency ultrasound scattering from microspheres and single cells, University of Toronto, Canada, 2004. ISBN 0973485019.

Contact

Princess Margaret Hospital, Room 8-306

610 University Avenue

Toronto, Ontario

CANADA M5G 2M9

Tel: (416) 946-4501 x5009 (lab)

e-mail: rbaddour@uhnres.utoronto.ca

Last updated: February 25, 2008