## 5 Conclusions  
In this initial exploratory study, an MLP-based regression model utilising [18F]FDG PET-CT-derived radiomic features demonstrated the ability to predict AAA growth rate with an accuracy of 1.35 mm/year. These promising initial results warrant validation in a larger prospective multi-centre cohort. In the future, more sophisticated stratification could guide individualised patient care facilitating tailored management of AAA.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/a18020086/s1](https://www.mdpi.com/article/10.3390/a18020086/s1)]([https://www.mdpi.com/article/10.3390/a18020086/s1](https://www.mdpi.com/article/10.3390/a18020086/s1)), Table S1: Tabulated TRIPOD Checklist; Table S2: PyRadiomic Customised Settings; Table S3: Radiomic Features; Table S4: All Radiomic Features; Table S5: Summary of Machine Learning Models and Performance.  
**Author Contributions:** Conceptualisation, P.A., N.R., M.A.W., R.F., A.F.F., J.H.F.R., M.A.B. and A.F.S.; methodology, P.A., N.R., M.A.W., R.F., A.F.F., J.H.F.R., M.A.B. and A.F.S.; software, N.J., G.M., J.Y.K., Y.H. and P.C.; validation, P.A., S.S.D., N.R., N.J., G.M., J.Y.K., Y.H. and P.C.; formal analysis, P.A., S.S.D., N.J., N.R., G.M., J.Y.K., Y.H. and P.C.; investigation, S.S.D., P.A., N.R., M.A.W., R.F., A.F.F., M.A.B. and A.F.S.; resources, A.F.S.; data curation, P.A., S.S.D., N.J., N.R., G.M., J.Y.K., Y.H. and P.C.; writing--original draft preparation, S.S.D., P.A., N.R., M.A.W., R.F., A.F.F., M.A.B. and A.F.S.; writing--review and editing, all authors; visualisation, P.A., S.S.D., N.J., N.R., G.M., Y.H. and P.C.; supervision, A.F.S.; project administration, A.F.S. All authors have read and agreed to the published version of the manuscript.  
**Funding:** [PERSON] and [PERSON] were supported by personal fellowships from the British Heart Foundation during the time of the work. J.H.F.R. is part-supported by the NIHR Cambridge Biomedical Research Centre (BRC), the British Heart Foundation, HEFCE, the EPSRC, and the Wellcome Trust. A.S. is part-supported by Cancer Research UK (C19942/A28832) and NIHR Leeds BRC (NIHR203331). DEN is supported by the British Heart Foundation (CH/09/002, RG/F/22/110093, RE/24/130012). The APC was funded by the authors personally. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR Leeds and Cambridge BRCs, or the Department of Health and Social Care. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.  
**Institutional Review Board Statement:** This study was conducted in accordance with the Declaration of Helsinki. Prospective informed written consent was obtained from all patients at the time of imaging for use of their anonymised [18F]FDG PET-CT imaging data in research and service development projects. Formal ethics committee approval was waived for this study, as it was considered by the institutional review board to represent an evaluation of a routine clinical service.  
**Data Availability Statement:** The data presented in this study are available on request from the corresponding author. The data are not publicly available due to institutional data-sharing restrictions.  
**Conflicts of Interest:** The authors declare no conflicts of interest.