In vivo quantification and densitometry of the MCP joint tissue on patients with rheumatoid arthritis

One of the main diagnostic criteria of Rheumatoid Arthritis (RA) is the radiologic evidence of a loss of bone-mass. In early stages it is the osteoporosis near affected joints advancing to cystic processes that result in joint destruction. A quantification of morphologic changes in the metacarpophalangeal (MCP) joint as an effect of RA provides a valuable insight into the pathogenesis of the disease and also provides an objective measure of the state of the degenerative process. An accurate in-vivo estimation of the MCP joint can be performed by means of computer-tomography (CT), however, for patients suffering from RA it is a painful if not impossible process to place their hands properly inside the CT-scanner along the principal axis of the gantry. Hence, the acquired image data is misaligned and measurement on this data will be inaccurate. A solution to the problem of re-alignment of the image data to the principal axes of the MCP joint and the quantification/densitometry of the bone-tissue are presented in this work.