The role of diffusion weighted magnetic resonance imaging for the characterisation of mediastinal lymphadenopathy.

e23113 Background: To assess the diagnostic performance and additional value of diffusion-weighted (DW) magnetic resonance imaging (MRI) in the characterization of mediastinal lymphadenopathy. Methods: This prospective study was approved by the institutional review board, and written informed consent was obtained from all patients. A total of 43 patients [23 males and 20 females with mean age of 49 years] with mediastinal lymphadenopathy underwent DW and T2 weighted MRI and pathological examination in the period of January 2015 to June 2016. Diffusion restriction pattern, apparent diffusion coefficient (ADC) mean value, size and T2 heterogeneous signal intensity of the nodes were evaluated. Receiver operating characteristic curve analysis was used to determine ADC mean threshold values. The best predicting combinations of these four parameters were selected by means of stepwise logistic regression analysis. Results: ADC mean value of malignant lymphadenopathy (0.873±0.109×10−3 mm2/s) was significantly different from that of benign lymphadenopathy (1.663±0.311×10−3 mm2/s) (P < 0.001). When an ADC mean value of 1.0955×10−3 mm2/s was used as a threshold value for differentiating malignant from benign nodes, the best results were obtained with a sensitivity of 94%, a specificity of 96% and area under the curve of 0.996. The three other predictor variables didn’t add anything statistically significant to the regression equation with ADC mean. Conclusions: ADC mean value of malignant mediastinal lymphadenopathy was significantly different from the benign lymphadenopathy. The ADC mean value was the strongest independent predictor of malignancy.