Paper

Physics-Informed Deep Learning for Improved Input Function Estimation in Motion-Blurred Dynamic \\(^18\\)FFDG PET Images

Kuttner, Samuel, Wetzer, Elisabeth, Salomonsen, Christian, Wickstrøm, Kristoffer K

2025

Overview

Kinetic modeling enables in vivo quantification of tracer uptake and glucose metabolism in [\\(^18\\)F]Fluorodeoxyglucose ([\\(^18\\)F]FDG) dynamic positron emission tomography (dPET) imaging of mice. However, kinetic modeling requires the accurate determination of the arterial input function (AIF) during imaging, which is time-consuming and invasive. Recent studies have shown the efficacy of using deep learning to directly predict the input function, surpassing established methods such as the image-derived input function (IDIF). In this work, we trained a physics-informed deep learning-based input function prediction model (PIDLIF) to estimate the AIF directly from the PET images, incorporating a kinetic modeling loss during training. The proposed method uses a two-tissue compartment model over two regions, the myocardium and brain of the mice, and is trained on a dataset of 70 [\\(^18\\)F]FDG dPET images of mice accompanied by the measured AIF during imaging. The proposed method had comparable performance to the network without a physics-informed loss, and when sudden movement causing blurring in the images was simulated, the PIDLIF model maintained high performance in severe cases of image degradation. The proposed physics-informed method exhibits an improved robustness that is promoted by physically constraining the problem, enforcing consistency for out-of-distribution samples. In conclusion, the PIDLIF model offers insight into the effects of leveraging physiological distribution mechanics in mice to guide a deep learning-based AIF prediction network in images with severe degradation as a result of blurring due to movement during imaging.

• Publisher: Cornell University Library, arXiv.org
• Subject: Blurring / Deep learning / Image degradation / Medical imaging / Myocardium / Physics / Physiological effects / Positron emission / Prediction models