Diagnostic accuracy of dual-energy CT for detecting bone marrow edema in patients with acute knee injuries: a systematic review and meta-analysis

Purpose: This systematic review and meta-analysis evaluated the diagnostic accuracy of dual-energy CT (DECT) for detecting bone marrow edema (BME) in adult patients with acute knee injuries. Methods: A systematic review of MEDLINE, EMBASE, Scopus, the Cochrane Library, and gray literature was performed from inception to January 31, 2020, using PRISMA-DTA guidelines. The review included studies assessing the diagnostic accuracy of DECT for detecting BME in at least 10 adult patients with acute knee injuries and with an MRI reference standard. Study details were independently extracted by two reviewers. Meta-analysis was performed using a bivariate mixed-effects regression model with subgroup analysis performed to evaluate for sources of variability. Risk of bias (ROB) was evaluated using the QUADAS-2 tool. Results: Eight studies evaluating 267 patients between the ages of 25–54 with acute knee injuries undergoing DECT and MRI were included in analysis. Summary sensitivity, specificity, and AUROC values for BME were 84% (95% confidence interval (CI) 74–91%), 96% (95% CI 93–98%), and 0.97 (95% CI 0.95–0.98), respectively. Bone-based characterization was found to have lower specificity than region-based characterization (83% (57–95%) versus 97 (96–98%), p < 0.05), but no difference in sensitivity. No other statistical differences were identified amongst study subgroups to account for presumed variability amongst studies. Most studies were rated low risk for bias and applicability concerns. Conclusion: DECT is specific and accurate for detecting BME in adult patients with acute knee injuries and can be used as an alternative to MRI, particularly when MRI is contraindicated or unavailable.