Biomechanical Stiffness of Gliomas, Meningiomas, and Schwannomas Assessed by MR Elastography and Virtual MR...

Tissue stiffness can be evaluated by MR elastography (MRE). As tissue stiffness features similarly affect water diffusion, this assumption needs validation across brain tumors.

To compare MRE and intravoxel incoherent motion (IVIM)-based virtual elastography (vMRE) in assessing the stiffness of gliomas, meningiomas, and schwannomas, and to evaluate associations with intraoperative stiffness, cerebral blood flow (CBF), clinical, and histopathological features.

Prospective.

Sxity patients (63.3% females) with 24 meningiomas, 28 gliomas, and 8 schwannomas.

3-T, spin-echo echo-planar imaging (SE-EPI) sequence for MRE and IVIM-based vMRE; arterial spin labeling (ASL).

Quantitative elastography-derived parameters (c, φ from MRE; μ_diff, sADC from vMRE) were extracted from 3D tumor segmentations. Zada grading was evaluated in all cases. CBF was measured by ASL in 36 cases. Immunohistochemistry for collagen, cluster of differentiation 163 (CD163) and hyaluronan binding protein (HABP) was performed in 28 cases.

Bland-Altman plots and intraclass correlation coefficients (ICCs) were used to evaluate inter-reader agreement of elastography-derived parameters. Pearson's coefficients were used to correlate CBF and histopathological markers with elastography-derived parameters. Spearman's coefficients were used to correlate Zada grade with elastography-derived parameters. Group comparisons were performed using one-way ANOVA with Tukey's post hoc test. Receiver operating characteristic (ROC) curve and DeLong's test were performed for stiffness prediction efficiency. p < 0.05 was considered significant.

vMRE parameters significantly correlated with MRE parameters (μ_diff -c: r = 0.635, sADC -c: r = -0.657). μ_diff best predicted intraoperative tumor stiffness and was positively correlated with intraoperative blood loss in meningiomas. μ_diff, φ, and sADC differed by resection extent in meningiomas. Stiffness correlated positively with CBF (in 36 cases), collagen, and CD163 (in 28 cases).

Both MRE and vMRE parameters demonstrated potential for predicting intraoperative tumor stiffness and showed correlation with CBF, collagen deposition, and CD163-positive macrophage infiltration.

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