MRI扩散加权像对松果体区生殖细胞瘤诊断价值的初步研究

Diagnostic value of MRI apparent diffusion coefficient in pineal region germinomas

目的松果体区生殖细胞瘤经磁共振成像(magnetic resonance imaging,MRI)常规序列检查可获得初步诊断,但由于缺乏特异性影像学表现,诊断准确率不高。本研究探讨MRI扩散加权像(diffusion weighted imaging,DWI)结合表观扩散系数(apparent diffusion coefficient,ADC)对松果体区生殖细胞瘤的诊断价值。方法选择临沂市人民医院2010-01-01-2018-01-31经手术病理或诊断性放疗确诊的16例颅内松果体区肿瘤患者,其中生殖细胞瘤10例,星形细胞瘤2例,松果体实质细胞瘤2例,畸胎瘤2例。患者治疗前均行MRI和DWI检查,分别测量各肿瘤的MRI序列参数值及ADC值。结果松果体区肿瘤间T1WI(P=0.78)、T2WI(P=0.86)、T2FLAIR(P=0.74)及增强T1WI值(P=0.35)均值差异无统计学意义,ADC值均值差异有统计学意义,P<0.01。松果体区生殖细胞瘤平均ADC值为(824.41±205.90)×10^(-6) mm/s,星形细胞瘤平均ADC值为(969.54±244.50)×10^(-6) mm/s,实质细胞瘤平均ADC值为(1 209.31±43.45)×10^(-6) mm/s,畸胎瘤平均ADC值为(1 949.40±161.39)×10^(-6) mm/s,松果体区肿瘤间ADC值均值差异有统计学意义,F=18.62,P<0.01。两两比较发现,松果体区生殖细胞瘤与松果体区畸胎瘤ADC值均值差异有统计学意义,P<0.01。结论 ADC值对诊断松果体区生殖细胞瘤有一定诊断价值。

OBJECTIVE The primary diagnosis of pineal region germinomas can be obtained by magnetic resonance imaging(MRI),but the accuracy of diagnosis is not high because of the lack of specific imaging features.This study aims to explore the value of diffusion weighted imaging(DWI)combined with apparent diffusion coefficient(ADC)in diagnosing pineal region germinomas.METHODS From January 1,2010 to December 31,2016,16 case pathologically or radiosensitivity testing conformed pineal region tumors were selected,including germinomas 10 case,astrocytomas 2 case,pineocytomas 2 case and teratomas 2 case.All the patients were given magnetic resonance imaging(MRI)and DWI examination.MRI sequence parameter values and the ADC value of these tumors were calculated.RESULTS There was no significant difference in T1 WI,T2 WI,T2 FLAIR and contrast-enhanced T1 WI values between pineal region tumors(Pvalues were0.78,0.86,0.74 and 0.35),while the mean value of ADC was statistically significant(P<0.01).The ADC value of pineal region germinomas,astrocytomas,pineocytomas and teratomas were(824.41±205.90)×10-6 mm/s,(969.54±244.50)×10-6 mm/s,(1 209.31±43.45)×10-6 mm/s,(1 949.40±161.39)×10-6 mm/s.Significant statistical difference was observed in pineal region tumors(P<0.01).Significant statistical difference was observed between pineal region germinomas and teratomas(P<0.01).CONCLUSION ADC value is valuable in diagnosing pineal region germ cell tumor.