Objective: To demonstrate the ability of a novel radiographic technique, Diffraction Enhanced Radiographic Imaging (DEI), to render high contrast images of canine knee joints for identification of cartilage lesions in situ.
Methods: DEI was carried out at the X-15A beamline at Brookhaven National Laboratory on intact canine knee joints with varying levels of cartilage damage. Two independent observers graded the DE images for lesions and these grades were correlated to the gross morphological grade.
Results: The correlation of gross visual grades with DEI grades for the 18 canine knee joints as determined by observer 1 (r2 = 0.8856, P = 0.001) and observer 2 (r2 = 0.8818, P = 0.001) was high. The overall weighted kappa value for inter-observer agreement was 0.93, thus considered high agreement.
Conclusion: The present study is the first study for the efficacy of DEI for cartilage lesions in an animal joint, from very early signs through erosion down to subchondral bone, representing the spectrum of cartilage changes occurring in human osteoarthritis (OA). Here we show that DEI allows the visualization of cartilage lesions in intact canine knee joints with good accuracy. Hence, DEI may be applicable for following joint degeneration in animal models of OA.