Abstract: Objective：To analyze the predictive value of preoperative diffusion tension imaging（DTI）quantitative analysis in patients with trigeminal neuralgia.Methods：270 patients with trigeminal neuralgia who underwent microvascular decompression in neurosurgery department of our hospital from May 2017 to April 2019 were prospectively analyzed.All patients received DTI before surgery，after half a year followup，the patients were divided into effective group and ineffective group according to the operation effect.Mean dispersion rate（MD），anisotropy score（FA），relative anisotropy（RA）and volume ratio index（VR）values were compared between the two groups.Results：Quantitative analysis results of DTI in the two groups were compared，MD in the invalid group was higher than that in the normal group（P<0.05），FA，RA and VR were lower than the effective group（P<0.05）.Multivariate Logistic regression analysis showed that：MD and the history of tooth extraction were independent risk factors for surgical outcomes in patients with trigeminal neuralgia；FA，RA and VR are protective factors affecting the surgical outcome of patients with trigeminal neuralgia.ROC curve shows：In the quantitative analysis of DTI，the predictive value of FA on the surgical effect of patients with trigeminal neuralgia was higher than that of MD，RA and TC，the optimal cutoff point of FA is less than 0.31×10-3 mm2/s，at this time，the sensitivity was 92.68% and the specificity was 60.29%.Conclusion：Preoperative DTI quantitative analysis in patients with trigeminal neuralgia can effectively predict the surgical effect of microvascular decompression.

Key words: diffusion tension imaging, trigeminal neuralgia, microvascular decompression, the ROC curve