Background: Several malignant tumors and brain abscesses have similar magnetic resonance imaging (MRI) findings. Because the prognosis and treatment strategies differ among these disorders, accurate preoperative diagnosis is very significant. Recently, diffusion-weighted imaging (DWI) and calculation of apparent diffusion coefficients (ADCs) have been reported to be useful to differentiate between the two disorders.
Materials and methods: MRI and DWI were performed in 37 patients: 13 with glioblastomas, 14 with metastatic tumors, 7 with malignant lymphomas, and 3 with brain abscesses. The minimum ADC value (ADC min ) and mean ADC value (ADC mean ) were taken into consideration.
Results: Statistically significant differences were found in the enhanced lesions for ADC min and ADC mean between metastatic tumors and malignant lymphomas. The receiver operating characteristic analyses revealed no statistically significant differences among them. There were statistically significant differences in ADC mean in the cores of cystic lesions between brain abscesses and metastatic tumors or glioblastomas.
Conclusions: Our results suggest that evaluation using ADC values may facilitate differentiating metastatic tumors from malignant lymphomas, and also metastatic tumors or glioblastomas from brain abscesses.