Musculoskeletal ultrasound in the Differential Diagnosis of Gouty Arthritis and Rheumatoid Arthritis

Objective: To explore the role of musculoskeletal ultrasound (MSUS) in the differential diagnosis of gouty arthritis (GA) and rheumatoid arthritis (RA) and to analyze the ultrasound imaging features of the two diseases. Methods: A retrospective study was carried out. A total of 66 patients who had been admitted to The First Medical Center of Chinese PLA General Hospital from May 2018 to March 2019 were enrolled. Among them, 34 patients were diagnosed with RA and were included in the RA group; 32 patients were diagnosed with gouty arthritis and were included in the GA group. The imaging features of musculoskeletal ultrasound were compared between the two groups of patients. Results: A total of 34 patients were included in the RA group, including 17 males and 17 females. A total of 32 patients were included in the GA group, including 14 males and 18 females. There were no significant differences in gender composition, age, and duration of disease between the two groups (P>0.05). In the RA group, there were joint bone erosions with a clear boundary in seven cases and with a blurred boundary in 27 cases; synovial hyperplasia was observed in 27 cases, and point-like hyperechoic masses were observed in four cases. In the GA group, there were joint bone erosions with a clear boundary in 27 cases and with a blurred boundary in five cases; synovial hyperplasia was observed in four cases, tophus was observed in 23 cases, point-like hyperechoic masses were observed in 27 cases, and the tram-track sign was observed in 23 cases. The differences in bone erosion boundaries (c(2)=26.854, P<0.01), synovial hyperplasia (c(2)=29.631, P<0.01), tophus (P<0.01), point-like hyperechoic mass (c(2)=33.095, P<0.01), and tram-track sign (P<0.01) were statistically significant between the two groups of patients. In the RA group, blood flow signaling was Grade 0 in one case, Grade-I in five cases, Grade-II in 14 cases, and Grade-III in 14 cases. In the GA group, blood flow signaling was Grade 0 in 26 cases, Grade-I in three cases, Grade-II in three cases, and Grade-III in zero cases. The difference in the synovial blood flow signaling between the two groups of patients was statistically significant (c(2)=34.323, P<0.01). Conclusions: MSUS has certain diagnostic value in the differentiation of GA and RA. Moreover, the two conditions have their own ultrasound imaging features.