ARTHRITIC TEMPOROMANDIBULAR-JOINT - CORRELATION OF MACROMOLECULAR CONTRAST-ENHANCED MR-IMAGING PARAMETERS AND HISTOPATHOLOGIC FINDINGS

PURPOSE: To assess the utility of macromolecular contrast material-enh anced magnetic resonance (MR) imaging parameters for determining the h istopathologic severity of temporomandibular joint (TMJ) arthritis. MA TERIALS AND METHODS: Ovalbumin was used to induce arthritis in the TMJ s of 10 previously sensitized adult white rabbits. Five rabbits compos ed the sham-treated control group. Dynamic spin-echo imaging was perfo rmed immediately before and for 30 minutes after injection of macromol ecular contrast medium. Histologic specimens of TMJ were assessed quan titatively for arthritis. Changes in MR signal intensity were derived from the synovial and subsynovial tissues of the TMJ, and plasma volum e (PV) and permeability surface area product (PS) were calculated. The se MR parameters and the arthritic scores were compared between sham-t reated and antigen-challenged TMJs. The relationships between MR param eters and histopathologic indexes were also determined. RESULTS: Arthr itic TMJs showed marked enhancement of the synovial and subsynovial ti ssues over the imaging period. PS and all histopathologic indexes of a rthritis were significantly greater (P < .005) in antigen-challenged t han in sham-treated TMJs. PS demonstrated strong positive relationship s with all histologic parameters of arthritis, indicating its utility for assessing the severity of joint inflammation. CONCLUSION: Macromol ecular contrast-enhanced MR imaging enables quantification of PS and P V in inflamed joints. This technique may provide insights into the pat hogenesis of joint inflammation and noninvasive monitoring of disease severity and treatment response in arthritis.