A proposed imaging scoring system to differentiate dural-based metastasis from meningioma using MR and CT images.

Background and purpose: The differentiation between dural-based metastasis and meningioma, which is the most common benign extra axial tumor, is crucial, particularly when staging patients with known primary neoplasms. The purpose of this study was to assess CT and MR imaging features and to validate a proposed imaging scoring system to differentiate between the two pathologies.

Materials and methods: A total of 84 patients with pathologically proven meningioma and 31 dural-based metastases were included in this retrospective study. The CT and MR imaging features, including the mean apparent diffusion coefficient (ADC), presence of edema, cystic changes, dural tail, leptomeningeal enhancement, calcifications, bone destruction and hyperostosis, were evaluated. The efficacy of the proposed imaging method for meningioma and its benign findings was evaluated.

Results: There was a significant difference in most of the imaging features between patients with meningiomas and those with dural-based metastasis. The presence of vasogenic edema, leptomeningeal enhancement and bone destruction was significantly greater in patients with dural-based metastasis. Bone destruction and leptomeningeal enhancement showed the highest specificity for dural-based metastasis. There was also a significant difference between the two pathologies according to the proposed scoring system, with a P value < 0.001. Receiver Operator Characteristic (ROC) curve analysis was done to optimize the cutoff point which was identified as score 2 and above which has high 89.6% diagnostic accuracy for meningioma.

Conclusion: The proposed imaging scoring system could be an effective tool for predicting the diagnosis of meningioma. This can be utilized to discriminate between meningioma and dural-based metastasis, particularly when staging patients with known primary neoplasms.