Measurement of radiographic changes in adjuvant-induced arthritis in rats by quantitative image analysis

Abstract

Objective. To apply quantitative analytical methods to the evaluation of radiographic images in experimental arthritis.Methods. Adjuvant was used to induce arthritis in rats. Arthritis progression was followed by conventional methods. In addition, digitized images of radiographs of the calcaneus were examined for changes in the mean and in the distribution pattern of gray values. Periosteal new bone formation was measured as an increase in image area of the calcaneus.Results. Significant changes in the gray value profile and increases in periosteal bone formation occurred in arthritic rats. More extensive changes occurred in Lewis rats than in Sprague-Dawley rats. Analysis of serial radiographs revealed an initial decrease in the density of juxtaarticular bone, followed by progressive increases in gray value variation due to concurrent bone loss and bone formation. Eventually, bone formation in arthritic rats resulted in increased gray values above those in nonarthritic rats.Conclusion. Image analysis represents a sensitive, quantitative method for detecting radiographic changes in experimental arthritis.The adjuvant-and collagen-induced models of chronic arthritis are widely used for studies of the underlying pathophysiology of joint disease and for the evaluation of potential new therapeutic agents. In both models, grossly apparent joint inflammation rapidly

Manipulation of the induction of adjuvant arthritis in Sprague-Dawley rats

“…6 and 7). These histopathological and radiological features observed in the current AIA model closely resemble the arthritic features of the AIA induced in Lewis rats [14,28].…”

“…Radiographs of each rat for evaluation of soft tissue swelling and bone erosion were scored blindly by two independent observers, on a scale of 0 (normal), 1 (mild changes), 2 (moderate changes) and 3 (severe changes) [14]. Total radiological scores were calculated from the sum of both hind paws, giving a maximum possible score of 6 for each radiological parameter per rat.…”

Nociceptive tolerance is improved by bradykinin receptor B1 antagonism and joint morphology is protected by both endothelin type A and bradykinin receptor B1 antagonism in a surgical model of osteoarthritis

“…Radiological scoring of the DX views of the knee joints [42,43] indicated that antagonist treatment protected joint radiomorphology after ACLT. One-way ANOVA with Holm post-hoc: a P = 0.0214, ACLT/BQ-123 treatment versus ACLT/saline treatment; b P = 0.0020, ACLT/R-954 treatment versus ACLT/saline treatment; c P = 0.0125, ACLT/BQ-123+R-954 dual treatment versus ACLT/saline treatment.…”

“…Images were analyzed using OsiriX software (version 3.7.1) [41]. Radiological evidence of joint degradation was scored by two blinded examiners using an OA radiological score modified from Clark et al [42] and Esser et al [43]. Bone demineralization, subchondral bone erosion, and heterotopic ossification were all scored on a scale from zero (normal) to three (marked degenerative changes).…”

A combination of methotrexate and zoledronic acid prevents bone erosions and systemic bone mass loss in collagen induced arthritis

“…The ankle and tarsus joints were graded for erosions (0 to 3) and soft-tissue swelling (0 to 3), with scores of 1 and 3 corresponding to no involvement and to extensive involvement, respectively [21]. Two observers blind to treatment assignment and with significant experience in reading and rating radiographs for patients with RA evaluated the radiographs.…”