[Quantitative thermography of the knee joint]

Computer-assisted evaluation of thermography of the knee joints allows diagnosis and quantitation of inflammatory processes. This needs an adequate thermography camera, registration standards and a thermographic index. With the aid of this index normal knee joints and those with inflammatory changes can clearly be differentiated: an index of less than 3.5 is normal, values above 5.0 indicate an inflammation. The author proposes to correct the thermographic index with reference to actual rectal temperature in order to improve inter- and intra-individual comparability of thermograms. Apart from the thermographic index, the formal analysis of the line-scan over the joint space and the maximal temperature of the joint can be used as further diagnostic criteria.