Post-embolisation susceptibility changes in giant meningiomas: multiparametric histogram analysis using non-contrast-enhanced susceptibility-weighted PRESTO, diffusion-weighted and perfusion-weighted imaging

Purpose To investigate imaging characteristics of post-embolised meningioma and to determine if SW imaging can delineate tumour ischaemia. Materials and methods Sixteen patients were studied before and after preoperative embolisation therapy (8 histopathologically determined with ischaemia, 8 with non-ischaemia). In each patient, a slice-wise ROI for the entire tumour was established, and histogram variables (mean, SD, minimum, maximum, histogram width, mode, and peak height) of SW, ADC, CBV, CBF, MTT, and TTP maps were compared between ischaemic and non-ischaemic groups. Changes in SW histogram were correlated with histopathological characteristics. Results Signal intensity on the SW map tended to decrease in the ischaemic group and partially increased in the non-ischaemic group. A similar trend was observed on the ADC map. The PW histogram showed an MTT increase in ischaemic group; however, CBV did not show significant changes between ischaemic and non-ischaemic groups. Microhaemorrhage was slightly correlated with Δpeak height in the SW histogram. Conclusion Post-embolisation changes of intrinsic T2*-weighted MR contrasts on SW map are most likely associated with alterations in deoxyhaemoglobin levels and arterial blood flow. Key Points • Endovascular embolisation is now accepted as an adjuvant therapy for intracranial meningioma. • Magnetic resonance imaging is used to assess the effects of embolisation. • Unenhanced susceptibility-weighted MRI can delineate ischaemic and non-ischaemic areas. • Signal changes at SW imaging are associated with diffusion and perfusion abnormalities. • Three-dimensional high-resolution SW imaging offers a new imaging biomarker in assessing ischaemia.