Detection of inflammation in early rheumatoid arthritis patients: a comparison study of single photon emission computed tomography combined with computed tomography and magnetic resonance imaging / 中华风湿病学杂志

ABSTRACT

Objective To evaluate the interactive relationship between inflammation detected by single photon emission computed tomography combined with computed tomography (SPECT/CT) and magnetic resonance imaging (MRI) detection of synovitis,bone marrow edema (BME) in the early rheumatoid arthritis (RA) patients.Methods Twenty patients with early RA were included into this study.All patients were diagnosed based on the 2010 ACR/EULAR classification criterion.Patients' unilateral hands (MCP 2-5 and PIP 2-5 joints) were inspected by SPECT/CT (label99Tcm-MDP) and MRI (3.0 T).SPECT/CT and MRI images were analyzed by two reviewers blinded to other clinical information.Increased bone metabolism of the regional area of interest (ROI) was analyzed and the uptake ratio was calculated.MRI quantitative evaluation was completed by RAMRIS score system.Statistical analysis was performed using SPSS 17.0 software.Student's t-test,analysis of variance (ANOVA),x2 test and post-hoc analysis (Scheffe) were used for comparison of datas,correlation analysis was carried out with Spearman rank correlation test.Results Twent ypatients with a total of 160 joints were examined.MRI examination revealed synovitis (39,24.4％),or BME (24,15.0％) in 63(39.4％) joints.99Tcm-MDP uptake increased in 79(49.4％) joints,and the uptake ratio was higher than normal joints (1.59±0.26 vs 1.15±0.09,t=6.408,P＜0.01).The uptake ratio between the graded synovitis level and RAMRIS synovitis score had a moderate correlation (r=0.535,P=0.001).The uptake ratio of BME level and BME score was well correlated (r=0.765,P=0.001).Conclusion In early RA patients,MRI is sensitive for synovitis and BME.SPECT/CT can detect early abnormal bone metabolism associated with inflammation,which is more sensitive than MRI.SPECT/CT can be used to detect changes of RA at the molecular level.Compared with synovitis,BME is more closely related to bone metabolism changes,which may suggest that BME may play a major role in the bone destruction in RA.However,further studies are needed to verify this hypothesis.