Diagnostic Efficacy of Diffusion-Weighted Magnetic Resonance Imaging (DWI) in the Differentiation of Benign and Malignant Cervical Lymphadenopathies

Abstract

Background: Pre-operative differentiation of benign from malignant cervical adenopathies remains a challenge. Several studies indicate parameters to discriminate between benign and malignant lymph nodes, which has not yet been enough. Objectives: The aim of the current study was to assess the diagnostic efficacy of diffusion-weighted MR imaging (DWI) to differentiate benign from malignant cervical lymph nodes. Patients and Methods: In all patients, we assessed axial and coronal fast spin echo T2 and T1-weighted images and T1-weighted after contrast injection. DWI sequences were implemented before contrast injection, in axial and coronal planes (b factor of 50, 500 and 1000 s/mm2) and the apparent diffusion coefficient (ADC) maps were reconstructed. Data were assessed in mixed model analysis and results were compared with postoperative histopathologic findings. Results: Thirty seven subjects were enrolled, 10 with benign lymphadenopathy and 27 patients with malignant lymphadenopathies before treatment. The mean ADC of the benign neck lymph nodes was (1.00 ± 0.34) × 10-3 mm2/s, while it was (0.76 ± 0.16) × 10-3 mm2/s in malignant ones (P = 0.058). The mean ADC of the metastatic nodes was (0.81 ± 0.14) × 10-3 mm2/s, while it was (0.56 ± 0.04) × 10-3 mm2/s in lymphoma (P < 0.001). The mean ADC of poorly differentiated metastatic nodes was significantly lower than that of good and moderately differentiated ones [(0.86 ± 0.13) × 10-3 mm2/s vs. (0.66 ± 0.02) × 10-3 mm2/s respectively; P = 0.001]. The area under the ROC curve of ADC was 0.69 [95%CI = 0.52 - 0.83]. Considering cut off points of 0.6 × 10-3, 0.95 × 10-3, and 1.2 × 10-3 yielded sensitivities were 15%, 92.5%, and 100%, respectively; while, in these cutoff points, specificities were 80%, 50%, and 40%, respectively. Conclusion: DWI could be considered as an important diagnostic tool to differentiate enlarged cervical lymphadenopathies.