Computed Tomography and Magnetic Resonance Appearance of Sporadic Meningioangiomatosis Correlated with Pathological Findings

Purpose: Meningioangiomatosis (MA) is a rare benign localized lesion of leptomeninges and underlying cerebral cortex. Preoperative diagnosis is difficult and challenging because of its diverse clinical, pathological, and imaging features. We retrospectively analyzed 7 cases of MA to explore their imaging features and correlate with pathological findings.

Materials And Methods: Imaging studies including computed tomography (CT) and magnetic resonance imaging (MRI) were retrospectively reviewed in 7 patients with surgically and pathologically verified intracranial MA (not associated with neurofibromatosis). Computed tomography studies were performed in axial plane without iodinated contrast-material administration; magnetic resonance studies consisted of axial T1-weighted, T2-weighted, Fluid attenuated Inversion Recovery (FLAIR), and postcontrast T1-weighted sequences and coronal or sagittal precontrast and postcontrast T1-weighted sequences.

Results: Computed tomography showed focal extensively calcified lesions in 3 cases, lesions with patchy calcification in 2 cases, and no apparent calcification in 2 cases. Magnetic resonance imaging demonstrated predominantly hypointensity on T1-weighted images and hyperintensity on T2-weighted images. Six of 7 cases exhibited gyriform hyperintensity on FLAIR sequences, which correlated with proliferating microvessels with perivascular cuffs of spindle-cell proliferation within the cortex on histopathological analysis. After contrast-material administration, all but 1 showed heterogeneous enhancement. The nonenhancing lesion on MRI was completely calcified on CT.

Conclusion: Gyriform hyperintensity on FLAIR sequence is the main MRI feature of MA, which correlates with proliferating microvessels with perivascular cuffs of spindle-cell proliferation within the cortex on pathological analysis. Plain CT scan is essential to demonstrate the extent of calcification of these lesions.