An image-based method to measure joint deformity in inflammatory arthritis: development and pilot study

Abstract

Quantifying joint deformity in people with rheumatoid (RA) and psoriatic arthritis (PsA) remains challenging. Here, we demonstrate a new method to measure bone erosions and abnormal periosteal growths, based on the difference between a predicted healthy and actual diseased joint surface. We optimized the method by creating and measuring artificial bone erosions and growths. Then we measured 46 healthy and diseased patient surfaces. We found average sensitivity errors of ≤0.27 mm when measuring artificial erosions and growths. Patients had significantly more bone erosion than healthy subjects. Surface based outcomes are a novel way to interpret and quantify bone changes in PsA and RA.

Keywords:

• Coherent point drift
• HRpQCT
• CT
• imaging
• inflammatory arthritis
• MCP

Acknowledgements

The authors would like to thank Janice Weaver and Tatiana Held for their assistance in patient enrollment, and Mina Al-awquati for her assistance in subject assessment.

Declaration of interest

A patent application has been submitted by WPI based on these results.

Additional information

Funding

This study was funded by a Collaborative Seed Grant from the University of Massachusetts Medical School and Worcester Polytechnic Institute.