OMPI Seminar: Particia Oliver and Graeme Wardlaw and Year-end BBQ

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Thursday, May 25, 2017

Time: 3:30 - 5:00 pm - Thursday 25 May 2017. Refreshments start at 3:15 pm. BBQ starting at 5 pm.

Location:NRC - 1200 Montreal Road, Building M-36 - Kelvin Room (please check in at the front desk).



1) Investigating energy deposition in glandular tissues for mammography using multiscale Monte Carlo simulations

By Particia Oliver, PhD student, Carleton University

Supervisor: Dr. Rowan Thomson

Abstract: Multiscale models of compressed breasts are developed, and a mammographic exam is simulated using Monte Carlo. These multiscale models combine varying levels of detail on different lengthscales: cell populations consisting of >1000 mammary epithelial cells and ~200 adipocytes are embedded throughout the breast tissue. We compute specific energy (energy imparted per unit mass) in mammary epithelial cell nuclei, and doses to corresponding macroscopic (~mm) voxels containing glandular issue for a 30 kVp Mo/Mo spectrum.

Mammography glandular voxel doses underestimate mean specific energies to epithelial cell nuclei by ~25%, with considerable variations (~82% relative to the mean for a glandular voxel dose of 4 mGy) in specific energy throughout corresponding cell populations, in addition to considerable dose variations (between 1 and 18 mGy) throughout the breast. Energy deposition within mammary epithelial cell nuclei is sensitive to microscopic model details including cellular elemental composition and nucleus size. Results may be relevant for radiation-­induced cancer risk evaluation in mammography.


2)  Computed Tomography (CT) Diagnostic Reference Levels (DRLs): Context, Canada, and Caveats

By Graeme Wardlaw, PhD, Health Canada

Abstract: The concept of the Diagnostic Reference Level (DRL) has existed for some time – dating back to publication of ICRP reports 60 and 73 in 1991 and 1996. With increased attention on radiation safety in recent years, especially in relatively higher dose procedures such as computed tomography (CT), DRLs have become widely developed and promoted as a means to help manage patient exposures while avoiding restrictive limits on imaging practice. A brief introduction to the DRL concept and proposed DRLs obtained from the recent National CT Survey will be presented, along with a summary of some important DRL limitations.

3) End of yeart BBQ

If you plan on attending the BBQ please RSVP to Byran Muir (Bryan [dot] Muiratnrc-cnrc [dot] gc [dot] ca) so that NRC folks get an idea of how much food to prepare.