Dual-energy CT for evaluating bone marrow oedema in RA: an observational single-center study

Objectives: Dual-energy CT (DECT) is a novel and more effective approach for identifying bone marrow oedema (BME) lesions than magnetic resonance imaging (MRI). We aimed to investigate the performance of DECT in diagnosing BME in rheumatoid arthritis (RA) patients and its potential for assessing RA disease activity. Methods: RA patients who underwent both DECT and 3.0-T MRI were assessed to determine the association of clinical features with DECT and rheumatoid arthritis magnetic resonance imaging scoring system (RAMRIS) score. DECT images were used to determine the BME diagnosis accuracy using receiver operating characteristic (ROC) curves analysis, with MRI images as reference. Results: We enrolled a total of 63 RA patients. An AUROC of 0.927 was observed to detect BME in the wrist and metacarpophalangeal joints of RA patients using DECT, with the corresponding sensitivity and specificity being 97.2% and 88.2%, false-positive and false-negative being 11.8% and 2.8%, and positive and negative predictive values being 98.2% and 83.3%. Positive correlations were observed between DECT BME score and ESR and CRP, and between DECT total score with ESR, CRP and disease activity score 28-ESR (P < 0.00625). Conclusion: DECT images demonstrated excellent diagnostic performance in identifying the extent of BME and could serve as a potential evaluative instrument for disease activity in RA patients.