Larsen is a software that allows fast, accurate, and reliable documentation of erosive and degenerative changes on radiographs of hands, wrists, and feet in rheumatoid arthritis. Based on these data, the program is able to calculate the score (currently the Larsen score is used, but the software is able to support other scoring systems as well) and to deliver diagnostic hints based on the morphologic changes. Examinations are stored in a database to facilitate the assessment of the long-term follow-up of patients. An accurate quantification of erosive diseases gives an appropriate assessment of the disease status at a given time, serial measurements of radiographic damage provides a view of the disease course and essential data for calculating a progression rate.

In addition to a fully operative Java stand-alone application, a Web-based demo version is available at: http://medexpert.msi.meduniwien.ac.at/Larsen .

Larsen has been developed by the Department of Medical Computer Sciences, University of Vienna, The Department of Radiodiagnostics, University of Vienna Medical School, and the Department of Internal Medicine III, University of Vienna Medical School.