Non-Traumatic Bone Marrow Edema of the Knee: Diagnostic Accuracy of Dual-Energy Computed Tomography in Comparison to MRI

Purpose; To evaluate the diagnostic accuracy of dual-energy computed tomography (DECT) to identify non-traumatic bone marrow edema (BME) of the knee. Methods; This prospective study, approved by the institutional review board, comprised a cohort of 40 consecutive patients (comprising 23 males and 17 females, with a mean age of 52.3 years) who underwent examination using Dual-Energy Computed Tomography (DECT) with settings of 80 kV and a tin filter at 150 kV, in addition to Magnetic Resonance Imaging (MRI), all conducted within 5 days. Subsequently, DECT data underwent post-processing and were evaluated by two experienced radiologists, resulting in the visualization of Bone Marrow Edema (BME) on color-coded maps. To determine the diagnostic accuracy of DECT in detecting BME, receiver operator curves and the area under the curve (AUC) were computed, with MRI serving as the reference standard. Interobserver agreement was calculated with k-statistics. A p-value <0.05 was considered significant. Results; At MRI, BME was identified in 30/40 patients, with 106/480 (22,1%) involved partitions. Sensitivity and specificity of Reader 1 were 67,9% (95% CI: 58,2 - 76,7) and 95,99% (95% CI: 93,5 - 97,7), respectively. Sensitivity and specificity of Reader 2 were 69,8% (95% CI: 60,1 - 78,3) and 95,99% (95% CI: 93,5 - 97,7), respectively. Similar diagnostic accuracy values were achieved by the 2 readers, with an AUC of 0.82 for R1 and 0.829 for R2 (p=.743). The inter-observer agreement was k=0.68. Conclusions; DECT is an accurate imaging technique for the evidence of non-traumatic BME of the knee when compared to MRI.