Correlation of Preoperative Diffusion-weighted Magnetic Resonance Imaging–based Virtual Elastography with Intraoperative Quantitative Tumor Stiffness in Meningiomas

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Tumor stiffness strongly influences exposure, extent of resection, operative time, and approach in meningioma surgery, but magnetic resonance imaging–based prediction still relies mainly on qualitative assessment. We evaluated whether a diffusion-derived stiffness surrogate calculated from diffusion-weighted magnetic resonance imaging–based virtual elastography correlates with intraoperative quantitative tumor stiffness in meningiomas and assessed its usefulness for preoperative stiffness prediction. Of 33 patients who underwent meningioma surgery between May 2022 and January 2025, 22 with both preoperative virtual elastography and intraoperative stiffness measurements were analyzed. Preoperative 3-Tesla diffusion-weighted magnetic resonance imaging with 2 b values was used to generate shifted apparent diffusion coefficient maps, and a single-slice volume of interest with a 5.51 mm slice thickness was manually delineated on the axial slice showing the largest tumor cross-sectional area. Intraoperative tumor stiffness of approximately 1-cm³ fresh specimens was measured with a rheometer and expressed as Young's modulus. The relationship between the diffusion-derived stiffness surrogate and stiffness was examined using Pearson correlation and multivariate linear regression. The diffusion-derived stiffness surrogate showed a significant negative correlation with tumor stiffness (r = −0.655, p = 0.00094), and this association remained significant after exclusion of embolized cases. Lower diffusion-derived stiffness surrogate values were associated with firmer tumors, whereas higher values were associated with softer tumors. These findings indicate that diffusion-weighted magnetic resonance imaging–based virtual elastography may provide a noninvasive, quantitative preoperative surrogate marker for estimating the stiffness of selected solid components of meningiomas and may offer adjunctive information for surgical planning.