Visual qualitative evaluation of diffusion-weighted imaging, apparent diffusion coefficient quantification and Ki-67 proliferation index for predicting atypia in surgical meningiomas, Görsel kalitatif difüzyon-ağırlıklı görüntüleme incelemesi, açık difüzyon katsayısı kantifikasyonu ve Ki-67 proliferasyon indeksinin cerrahi meningiomlarda atipi tahminindeki yeri

Abstract

Objectives: The goal of this study was to investigate the efficiency of visual qualitative evaluation using diffusion-weighted (DW) imaging, apparent diffusion coefficient (ADC) quantification, and Ki-67 proliferation labeling index in grading intracranial meningiomas and compare the results with our reference standard for histopathology. Methods and Materials: Thirty-five consecutive patients with pathologically confirmed intracranial meningiomas were enrolled in the study. Their conventional magnetic resonance (MR), contrast-enhanced MR and DW images and ADC maps were investigated. Results: Eight patients (23%) had atypical meningioma (5 women and 3 men, mean age: 57.1±15.8 years), 27 (77%) had low-grade-typical meningioma (19 women, 8 men, mean age: 54.3±14.0 years). The most frequent histological subtype was the meningothelial type in both low-grade (37%) and atypical meningiomas (59%). The mean Ki-67 proliferation index for low-grade and atypical meningiomas were 2.31±1.44% (range: 1-5) and 7.37 ± 2.72% (range: 3-10), respectively. Meningiomas with Ki-67 proliferation index higher than 4% (except one) were atypical (P<0.001). In visual qualitative evaluation, diffusion restriction was significantly more common in atypical meningiomas (P<0.05). In quantitative evaluation, benign and atypical tumor groups had no significant difference in mean ADC values (P=0.471). Conclusion: We suggest that visual qualitative evaluation of DW imaging may be helpful to predict atypia and the risk of recurrence in patients with surgically treated meningiomas. © 2018 Elsevier B.V., All rights reserved.