最小ADC值对四脑室区肿瘤诊断与分级的价值

The Value of the Minimum ADC Value in the Diagnosis and Grading of Tumors in the Fourth Ventricle

目的:探讨最小ADC值对四脑室区肿瘤诊断及分级的价值。方法:回顾性分析41例四脑室区肿瘤的常规MR、DWI表现,以病理结果进行分类,WHOⅢ~Ⅳ级为高级别组,WHOⅠ~Ⅱ为低级别组,对两组最小ADC值进行统计学分析。结果:19例被分为高级别组,平均最小ADC值为(0.69±0.31)×10^(-3) mm^2/s;低级别组22例,平均最小ADC值为(1.50±0.45)×10^(-3)mm^2/s,两组差异有统计学意义(t=7.88,P<0.001);根据ROC曲线,以最小ADC值0.934×10^(-3) mm^2/s为阈值,判定四脑室区高级别肿瘤的敏感性为100%,特异性为92.6%,阳性预测值95%,阴性预测值100%。结论:最小ADC值对术前第四脑室区肿瘤的诊断与分级有明确的临床应用价值。

Objective:To study the value of the minimum ADC value in the diagnosis and grading of four-ventricular tumor.Methods:Total 41 patients with pathologically proved four ventricle tumors underwent MR examination,including DWI.MRI features were analyzed retrospectively.According to the pathological results,the patients were divided into two groups:WHO Ⅲ~Ⅳ was the high-grade group and WHOⅠ ~ Ⅱ was the low-grade group;the minimum ADC values of the two groups were measured and analyzed statistically.Results:Among the 41 cases,19 cases were in the high-grade group,the mean minimum ADC value was(0.69±0.31)×10^(-3) mm^2/s,22 cases were in the low-grade group,the mean minimum ADC value was(1.50±0.45)×10^(-3) mm^2/s.The independent samples t-test indicated that the mean minimum ADC value was significantly different between the two groups(t=7.88,P<0.001).According to the ROC curve,the minimum ADC value was 0.934×10^(-3) mm^2/s as the threshold,the sensitivity of high-grade tumor was 100% specificity was 92.6%,positive predictive value was 95%,negative predictive value was 100%.Conclusion:The minimum ADC value is useful to improve the preoperative diagnosis and grading of tumors in the fourth ventricle.