Experiment study on MR diffusion weighted imaging in rabbit models of lymphadenopathy: comparison between inflammatory and metastatic lymph node

Objective: To investigate the value of MR DWI in comparing inflammatory with metastatic lymph node in animal models of lymph disease. Methods: Eighteen rabbits with benign lymphadenopathy and 9 rabbits with malignant lymphadenopathy underwent routine MRI and DWI examination. Independent-samples t test was used to compare the sizes and apparent diffusion coefficient (ADC) values between the two groups. Results: Thirty-four inflammatory lymph nodes and 18 metastatic lymph nodes were observed. The size of lymph nodes was (8.14±2.79) and (6.29±1.48) mm in the benign and malignant groups, respectively. There was no significant statistical difference between the sizes of the two groups (t=2.624, P>0.05). Mean ADC value of lymph nodes was (1.19±0.31) x 10-3 mm2/s and (1.31±0.27) x 10-3 mm2/s in the benign and malignant groups, respectively. There was no significant statistical difference between the ADC values of benign and malignant lymph nodes (t=1.449, P>0.05). Conclusion: DWI sequence can be used to show lymphadenopathy, but the ADC value is insufficient to differentiate benign lymph nodes from malignant lymphadenopathy. (authors)