Rheumatoid arthritis quantification using appearance models

Abstract

Rheumatoid arthritis (RA) is a chronic disease that affects joints of the human skeleton. During therapy and during clinical trials, the accurate and precise measurement of the disease development is of crucial importance. Manual scoring frameworks exhibit high inter-reader variability and therefore constrain therapeutical monitoring or comparative evaluations during clinical trials.In this chapter an automatic method for the quantification of rheumatoid arthritis is described. It is largely based on appearance models, and analyses a radiograph with regard to the two main indicators of RA progression: joint space width narrowing and erosions on the bones. With the automatic approach a transition from global scoring methods that integrate over the entire anatomy, towards local measurements and the tracking of individual pathological changes becomes feasible. This is expected to improve both specificity and sensitivity of imaging biomarkers. It can improve therapy monitoring in particular if subtle changes occur, and can enhance the significance of clinical trials.