TrackVis模型示踪角度阈值对子宫肌瘤DTI纤维示踪成像结果的影响

Effect of TrackVis-Based Angle Threshold on DTI Fiber Tractography in Uterine Fibroid

目的探讨TrackVis模型下示踪角度阈值选择对子宫肌瘤扩散张量成像（DTI）纤维示踪成像导出参数的影响,以确定该模型的最佳角度阈值。方法 25例子宫肌瘤患者行常规MRI平扫及DTI扫描,采用25°、30°、35°、40°、45°5个不同的示踪角度阈值进行纤维追踪,测量5个不同角度下肌瘤的ADC值、FA值、纤维束密度、最长纤维束长度及平均纤维束长度进行比较。结果随着示踪角度阈值的递增,最长纤维束长度、纤维束密度、平均纤维束长度均递增,但FA值随着示踪角度阈值的增加而减小,40°与45°间FA值没有差异。结论 DTI纤维示踪角度阈值影响了导出参数FA值、最长纤维束长度、平均纤维束长度、纤维束密度,当角度为45°时纤维束长度及密度值最大,FA值趋于稳定,故子宫肌瘤的纤维示踪成像可选择45°为较优示踪角度阈值。

Objective To investigate the effect of TrackVis-based angle threshold on DTI fiber tractography in uterine fibroid. Methods The routine MRI and DTI were performed on 25 patients with uterine fibroids. DTI fiber tractography were performed with angle threshold at 25°、30°、35°、40°、45°,respectively. The apparent diffusion coefficient（ ADC） value,fractional anisotropy（ FA） value,density of fiber bundle,length of the longest fiber bundle and the average length of fiber bundles were measured and compared. Results Density of fiber bundle,length of the longest fiber bundle and the average length of fiber bundles were increased as the Angle threshold increased,while the the FA value decreased. There were no statistically significant differences in FA value between 40° group and 45° group. Conclusion Angle threshold can affect the DTInderived FA values,density of fiber bundle,length of the longest fiber bundle and the average length of fiber bundles,length of fiber bundles and density were maximum and FA value tended to be stable at 45 °. 45 ° of angle threshold may be optimum on DTI fiber tractography in uterine fibroid.