Identification of bone marrow edema around the ankle joint in non-traumatic patients: Diagnostic accuracy of dual-energy computed tomography

OBJECTIVES: To evaluate the diagnostic accuracy of DECT in the identification of BME of the ankle in non-traumatic patients.METHODS: This prospective institutional review board approved study included 40 consecutive patients (21 males and 19 females, mean age 56.8years, SD=11.37) that were examined using DECT and MRI in the period between April 2019 and January 2020. Two radiologists (7 and 16years of experience) evaluated the presence of BME on DECT mages. Diagnostic accuracy values for diagnosing BME on a per-patient and on a per-partition basis analysis were calculated for DECT images by two readers (R1 and R2, with 16 and 7years of experience, respectively), using MRI as a gold-standard for diagnosis. Inter-observer agreements were calculated with k-statistics. A p-value of <0.05 was considered as statistically significant.RESULTS: MRI depicted BME in 29/40 patients (72.50%) and in 43/240 partitions (17.91%). The consensus reading by R1 and R2 of DECT images allowed us to achieve 89.7% sensitivity (26/29 patients) and 81.8% specificity (9/11 patients). Regarding the partitions-basis analysis, BME was depicted by DECT in 39/43 partitions (90.69% sensitivity), and ruled out in 189/197 partitions (95.93% specificity). Sensitivity and specificity for the most involved partitions (talar dome) were both 95%. The inter-observer agreement for patients' analysis was substantial (k=0.697), whereas for the partitions' analysis, it ranged from substantial (k=0.724) to near perfect (k=0.950).CONCLUSIONS: DECT can accurately diagnose BME of the ankle in a cohort of non-traumatic patients.