Synthetic MRI for Evaluation of Brain Gliomas Grade and Tumor Proliferative Activity：A Retrospective Study

Abstract PURPOSE The evaluation of gliomas grade and proliferation contribute to improve prognosis. We explored the clinical value of synthetic MRI in evaluating quantitatively gliomas grade and predicting tumor proliferative activity. METHODS Forty-six patients with histopathologically proven gliomas were included in this study and underwent MAGnetic resonance Image Compilation within 1 week before surgery. T1 values pre- and post-contrast agent (T1-pre, T1-Gd) and T2 values pre-contrast agent (T2-pre) were measured in tumor solid parts and normal white matter of contralateral mirror. T1 and T2 values were compared with gliomas grade and expression of proliferation marker Ki-67. Receiver operating characteristic analysis was performed to assess the diagnostic performance of each metric. RESULTS The values of T1-pre, ΔT1[(T1-pre) – (T1-Gd)] and Ki-67 labeling index (Ki-67 LI) were significantly higher in the group of high-grade gliomas ( HGGs, n = 26) compared with the group of low-grade gliomas ( LGGs, n = 20), whereas T1-Gd and the ratio of T1-Gd (rT1-Gd, tumor-to-normal ratio) values were significantly lower in the group of HGGs compared with the group of LGGs. Receiver operating characteristic analysis curves showed that ΔT1 values had the highest diagnostic value (sensitivity: 96.20%, specificity: 60.00%) for gliomas grade, and the optical cut-off value was 277.88ms. T1-pre (rs=0.47, P = 0.001) and ΔT1 (rs=0.56, P༜0.001) values were positively correlated with Ki-67 LI. T1-Gd (rs=-0.42, P = 0.004) and rT1-Gd (rs=-0.40, P = 0.007) values were negatively correlated with Ki-67 LI. CONCLUSIONS Synthetic MRI is helpful to distinguish HGGs from LGGs and predict the tumor proliferative activity.