Additional value of dual-energy CT to differentiate between benign and malignant mediastinal tumors: An initial experience

Objectives: To investigate the feasibility of dual-energy computed tomography (DECT) in differentiating malignant from benign mediastinal tumors. Materials and methods: We prospectively enrolled 25 patients (14 males; mean age: 56.7 years) who had suspected mediastinal tumors on chest radiography or non-contrast chest computed tomography (CT). All patients underwent a two-phase DECT using gemstone spectral imaging (GSI) mode (GE HD750). For the quantitative analysis, two investigators measured the following parameters of the tumors in the early and the delayed phases: CT attenuation value in Hounsfield units (HU) and iodine concentration (mg/ml). Pathological results were used for a final diagnosis. Statistical analyses were performed using the Fisher's exact test and the Mann–Whitney t-test. Results: 10 patients (40%) had benign pathology, while 15 (60%) had malignant pathology. The iodine concentration measurements were significantly different between benign and malignant tumors both in the early phase (1.38 mg/ml vs. 2.41 mg/ml, p = 0.001) and in the delayed phase (1.52 mg/ml vs. 2.84 mg/ml, p = 0.001), while mean attenuation values were not significantly different in both phases (57.8 HU vs. 69.1 HU, p = 0.067 and 67.4 HU vs. 78.4 HU, p = 0.086, respectively). Conclusions: Dual-energy CT using a quantitative analytic methodology can be used to differentiate between benign and malignant mediastinal tumors