Prediction of Mechanical Properties and Subjective Consistency of Meningiomas Using T1-T2 Assessment Versus Fractional Anisotropy

OBJECTIVE: This study aims to evaluate quantitatively the mechanical properties of meningiomas and their correlation with the qualitative surgeon's assessment of consistency, as well as comparing the capability to predict tumor consistency of fractional anisotropy values calculated from the diffusion tensor imaging and T1/T2 signal intensities. METHODS: Sixteen patients with the diagnosis of intracranial meningioma were included. Fractional anisotropy values were calculated and T1/T2 assessment was performed. The qualitative assessment of the tumor consistency intraoperatively was determined by a neurosurgeon and quantitative assessment was obtained with the Warner-Bratzler mechanical test. RESULTS: Surgeon's qualitative assessment was concordant with the cutting force obtained from the mechanical tests (P = 0.046). There was a high correlation between tumor consistency reported by the surgeon and T1/T2 assessment (0.622/P = 0.01) and a moderate correlation with cutting force (0.532/P = 0.034) and elasticity (0.49/P = 0.05). Fractional anisotropy values for hard tumors were not significantly higher than for soft tumors (P = 0.115). There was no significant correlation between the fractional anisotropy and mechanical measurements (0.192/P = 0.3). Predictions of hard consistency in meningiomas were obtained with a sensitivity of 25% and a specificity of 100% when using the T1/T2 assessment and a sensitivity of 87.5% and a specificity of 50% when using the fractional anisotropy value. CONCLUSIONS: Qualitative surgeon's assessment was in accordance with measured mechanical properties. Fractional anisotropy value was not an independent predictor for tumor consistency and was not correlated with the mechanical tests results. T1/T2 assessment was correlated with mechanical properties and it can be used to discriminate very hard or soft tumors.