Evaluating the Effectiveness of Training a Generative Adversarial Network Through Transfer Learning for the Purpose of Completing CT Images
Date
2025-08-14
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Abstract
This thesis develops an image completion neural network to mitigate computed tomography (CT) artifacts without the use of large clinical datasets or sinogram data. It aims to demonstrate that by using the developed technique, artifacts can be mitigated accurately by simply replacing a given artifact-marred region with context-appropriate anatomy. Such an approach could have implications for how artifacts are dealt within the context of radiotherapy treatment planning.
The first chapter contains the preface and thesis outline. Chapters two through four outline the background knowledge that is required to understand the motivation for, and methods of, this work. Chapter five contains a research manuscript intended to address the need for a method which can correct artifacts on CT images used for radiotherapy treatment planning more effectively than current standard of care methods. This study employs a generative adversarial network (GAN)-based image completion network and uses transfer learning techniques in its approach.
Description
The experiment was conducted via a three-step approach. Firstly, hyperparameter tuning was completed to broadly support the image completion GAN’s ability to complete greyscale images. Secondly, transfer learning experiments were conducted using three different pretraining datasets, with the addition of the in-house dataset as a baseline. These experiments were undertaken to refine the generator’s ability to complete CT images and test whether transfer learning enhances completion performance when fine-tuning on the in-house dataset. Lastly, layer freezing was investigated as a way to further refine CT image completion performance. This three-step iterative GAN-optimization process is novel within the context of CT image completion.
Keywords
Generative Adversarial Network, Computed Tomography, Image Completion, Artificial Intelligence, Machine Learning