Hemangiopericytoma from meningioma - is diffusion weighted imaging useful in their differentiation?

Abstract

Purpose: Hemangiopericytoma and Meningioma appear similar on routine diagnostic imaging. Diffusion weighted images (DWI) has been used to characterize different types of tumors. The purpose of this study was to assess whether DWI can be used to differentiate hemangiopericytoma from meningioma on diagnostic imaging. Materials and Methods: In a retrospective study, our tumor database was analyzed for diagnosis of hemangiopericytoma with DWI available at the time of diagnostic imaging. These patients were then matched based on location and size of the tumor in a ratio of 1 hemangiopericytoma vs. 2 matched meningioma. The minimum and mean Apparent Diffusion Coefficient (ADC) was measured in the tumor and the contralateral Normal Appearing White Matter (NAWM) to calculate a normalized ADC (nADC) as the ratio of the two. The two tumors were also subjectively assessed for their heterogeneity. Results: Seven patients with histopathological diagnosis of hemangiopericytoma were matched based on size and location with 14 patients of meningioma. Primary meningioma were significantly homogeneous (p<0.001) in appearance compared to hemangiopericytomas. Hemangiopericytomas had a higher mean ADC compared to that of meningioma (p<0.001). Conclusion: Hemangiopericytoma showed heterogeneity on DWI and significantly higher ADC compared to that of meningiomas in our small study. This needs to be confirmed in a study with a larger sample size.