Diffusion-weighted MRI in cervical lymph nodes: Differentiation between benign and malignant lesions

Objective: Purpose of our study was to assess the potential role of diffusion-weighted imaging (DWI) in the differential diagnosis between benign and malignant nodes. Subject and methods: We enrolled 32 subjects: 14 with benign lymphadenopathy, 17 patients with histologically proved malignant disease before beginning treatment and 1 patient with lymphoma after chemotherapeutic treatment. In all patients we used fast spin echo T2-weighted images in axial and coronal planes, fast spin echo T1-weighted images before and after contrast medium of administration in axial and coronal planes. Before contrast administration diffusion sequences were acquired on the axial and coronal plane (b factor of 0.500 and 1000 s/mm(2)) and then apparent diffusion coefficient (ADC) maps were reconstructed. Results: On diffusion images, 13/14 patients with benign nodes showed low signal intensity and had high signal on ADC maps, whereas all patients with malignant diseases appeared hyperintense on diffusion images and with low signal intensity on ADC maps. Only a patient with tuberculosis showed a low ADC value. The mean ADC value of malignant nodes was about 0.85 x 10(-3) mm(2)/s, the mean value of benign nodes was 1.448 x 10(-3) mm(2)/s; this difference was statistically significant (p < 0.01). The mean ADC value of treated nodes was 1.75 x 10(-3) mm(2)/s. The best threshold value was 1.03 x 10(-3) mm(2)/s, obtaining a sensitivity of 100% and a specificity of 92.9%. Conclusions: Diffusion imaging could be considered an important supportive tool for the diagnosis of enlarged cervical lymphadenopathies. (C) 2009 Elsevier Ireland Ltd. All rights reserved.