The association between rheumatoid arthritis and masticatory muscles through the utilization of diffusion‐weighted magnetic resonance imaging

Objective The objective of this study was to investigate the association between rheumatoid arthritis (RA) and masticatory muscles by analyzing the apparent diffusion coefficient (ADC) obtained from diffusion‐weighted magnetic resonance imaging (DW‐MRI). Materials and Methods In this retrospective study, we analyzed data from 36 patients who underwent MRI examinations at our hospital from August 2006 to March 2022. We also included a control group consisting of 39 patients with normal TMJs who were examined during the same time frame. To compare the ADC values of the masticatory muscles between the two groups, DW‐MRI was employed. Results RA patients exhibited significantly higher mean ADC values in the medial and lateral pterygoid muscles compared to the control group. Receiver operating characteristic (ROC) curve analysis indicated cutoff values of 1.14, 1.15, and 1.28 for the ADC values of the masticatory muscles in RA patients, with corresponding maximum ADC under the curve values of 0.53, 0.60, and 0.65. Conclusions The study revealed a notable distinction in the condition of the masticatory muscles between patients with RA and the control group, implying that the ADC measured through DWI holds promise for evaluating the association between masticatory muscles and RA. Furthermore, these findings suggest that DWI could serve as a valuable tool in identifying the presence of RA.