Alternative imaging technique and an automated image processing algorithm for the early detection of the precursory changes of rheumatoid vasculitis

Abstract

The purpose of this research was to use diagnostic ultrasound imaging to identify the precursory changes of rheumatoid vasculitis (RV) within the proximal dorsalis pedis artery (DPA). Participants with and without rheumatoid arthritis (RA) (n=100) were examined within this study. The research used quantitative analyses pertaining to demographic questions and analytical measurements from the ultrasound images. The findings from this research have indicated a high presence of wall thickening (≥96%) in the proximal DPA for people with RA. The wall thickening indicates the precursory changes of RV have a role in the disease process of RA due to the increased prevalence. These changes indicating RV were previously thought to be rare. Additionally, the changes in the function of the wall of the DPA retains mobility within normal limits which has been demonstrated through Doppler ultrasound. Therefore, as the function is within normal limits, further clinical management would be unlikely to be requested resulting in underdiagnosis of RV. Additional to these observations, concentric contraction of the proximal DPA was noted in participants who have had RA greater than 5 years. This contraction has also not previously been documented and may indicate an underlying vascular cause for the increased prevalence of interstitial lung disease and cardiac death for people with RA. An automated imaging process algorithm was also created from the ultrasound images of the DPA. The algorithm was successfully created using a principal component analysis and linear discriminant analysis from over 3000 images. The successful algorithm and imaging biomarker provide a potential screening tool for the detection of the precursory changes of RV. The algorithm may be beneficial in rural and remote areas where specialist care or sonographic assessment may not be available.

Date of Award	2025
Original language	English
Awarding Institution	Western Sydney University
Supervisor	Roy Cheung (Supervisor), Stefania Penkala (Supervisor) & Rosa H. M. Chan (Supervisor)