ANALYZING THE PRECISION OF JSW MEASUREMENTS USING 3D SCANS AND STATISTICAL MODELS

One of the methods to diagnose rheumatoid arthritis (RA) is measuring joint space narrowing over time. A method is pre- sented to analyze the sensitivity of this measurement to position- ing of the hand. Micro-CT scans are used to generate projections of a joint under varying angles of rotation. A semi-automatic method is used to measure the joint space width (JSW) for each projection. A Statistical model is used to investigate whether the rotation can be detected from a 2D radiograph. It is shown that rotation of the hand has a significant influence on the measured JSW.