Student Presentation
Cordell Steele, MSc Student, Carleton University (Supervisor: Glenn Wells)
Title: A Deep Learning Approach to Reconstruction-Based Scatter Compensation with Multi-pinhole SPECT
Abstract: Single-Photon Emission Computed Tomography (SPECT) is widely used for cardiac evaluation but often yields images of suboptimal quality due to noise. At the University of Ottawa Heart Institute (UOHI), multi-pinhole SPECT systems with Cadmium Zinc Telluride (CZT) detectors use Maximum-Likelihood Expectation Maximization (MLEM) for image reconstruction. Current scatter correction techniques subtract estimated scatter from the total signal, potentially discarding useful spatial information. We propose a Reconstruction-Based Scatter Compensation (RBSC) method that uses deep-learning to integrate features from scatter estimations directly into the iterative reconstruction process to enhance image quality. To make this approach computationally feasible, we developed a convolutional autoencoder trained on 11,000 image samples to generate scatter estimates, achieving an average MSE of 
and SSIM of 
compared to ground truth. These results suggest that we have a machine learning (ML) tool to estimate scatter efficiently. For future work, we intend to integrate this ML model into a reconstruction algorithm and hypothesize that this will improve SNR.
Member Presentation
Ruth Wilkins, PhD, Research Scientist, Manager, Ionizing Radiation Health Sciences Division, Health Canada
Title: Beyond the Bench: The International Activities of a Radiation Research Scientist
Abstract: Being a radiation research scientist extends beyond laboratory experiments to global collaboration to ensure that science, policy, and practice remain aligned in protecting people and the environment. This seminar will provide an overview of the international side of a radiation research scientist’s work, highlighting contributions to key organizations that shape global radiation protection. Drawing on experience across multiple bodies—including the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), The World Health Organization (WHO), the International Organization for Standardization (ISO) and others, the presentation will illustrate how scientific evidence informs policy, standard setting, dosimetry practices, and emergency preparedness. The seminar will describe how active engagement in international work can enhance the impact of research and encourage international collaboration, while enriching one’s scientific career. Ultimately, this session highlights the importance—and the responsibility—of bridging bench level research with international decision making to advance health, safety, and evidence based policy around the world.