扩散系数值在脑星形细胞肿瘤病理学分级中的应用  

Study of the apparent diffusion coefficient values in the grading of cerebral astrocytic tumors

作　　者：李茂[1] 邓德茂[1] 李荣富[1] 梁漱溟[1] 黄志碧[2] 叶伟[1] 李文美[1] 莫维光[3] 

机构地区：[1]广西医科大学第一附属医院放射科,南宁530021 [2]广西医科大学统计学教研室 [3]广西医科大学第一附属医院病理科,南宁530021

出　　处：《中华放射学杂志》2007年第10期1057-1061,共5页Chinese Journal of Radiology

基　　金：广西科学基金资助项目(0575016)

摘　　要：目的探讨扩散系数值对脑星形细胞肿瘤病理学分级的应用价值。方法对56例脑星形细胞肿瘤进行扩散加权成像(DWI)检查,分别测量肿瘤实质部分、瘤周水肿区、瘤周 T_2WI 正常表现白质区(瘤周白质区)、瘤体镜面对侧正常白质区及瘤周镜面对侧正常白质区的表观扩散系数(ADC)值和指数扩散系数(EDC)值,并计算肿瘤实质部分、瘤周水肿区、瘤周白质区的相对表观扩散系数(rADC)值和相对指数扩散系数(rEDC)值。分析各测量区的扩散系数值与肿瘤病理学分级的关系。结果 56例脑星形细胞肿瘤经手术病理证实,低级星形细胞瘤35例(Ⅰ、Ⅱ级),间变性星形细胞瘤8例(Ⅲ级),胶质母细胞瘤13例(Ⅳ级)。低级星形细胞瘤、间变性星形细胞瘤和胶质母细胞瘤肿瘤实质部分的 ADC 值分别为(1.44±0.26)×10^(-3)、(0.98±0.22)×10^(-3)和(0.83±0.15)×10^(-3)mm^2/s,rADC 值分别为(1.91±0.39)%、(1.34±0.33)%和(1.06±0.20)%,EDC 值分别为0.26±0.11、0.39±0.09和0.44±0.07,rEDC 值分别为(0.55±0.20)%、(0.81±0.19)%和(0.98±0.16)%,各指标间差异均有统计学意义(F 值分别为36.189、31.756、19.623和24.760,P 值均为0.000)。高级星形细胞瘤(间变性星形细胞瘤和胶质母细胞瘤)的肿瘤实质部分的 ADC 值和 rADC值分别为(0.89±0.19)×10^(-3)mm^2/s 和(1.17±0.28)%,明显低于低级星形细胞瘤(t 值分别为8.332和7.620,P 值均为0.000),EDC 值和 rEDC 值分别为0.42±0.08和(0.91±0.18)%,明显高于低级星形细胞瘤(t 值分别为-6.082和-6.776,P 值均为0.000)。以低级星形细胞瘤实质部分的rADC 值的下限(1.52%)作为判断低、高级别星形细胞瘤阈值的准确性为89.3%。结论肿瘤实质部分的扩散系数值对脑星形细胞肿瘤的病理学分级准确性较高,尤以 rADC 值为佳。Objective To investigate the diagnostic value of the apparent diffusion coefficient （ADC） values in the grading of cerebral astrocytic tumors. Methods Diffusion weighted MR imaging （DWI） was performed for 56 cases of cerebral astrocytic tumors proved pathologically. The ADC and the exponential diffusion coefficient （EDC） values were measured at the tumoral core, peritumoral edematous region, peritumoral normal-appearance white matter and the contralateral white matter. The rADC and rEDC values of the tumoral core, peritumoral edematous region and peritumoral normal-appearance white matter were calculated. The relationship between the various diffusion coefficient values and tumor grading was analyzed. Results Fifty six cases of cerebral astrocytic tumors included 2 pilocytic astrocytoma （ grade Ⅰ ）, 33 astrocytoma （ grade Ⅱ ）, 8 anaplastic astrocytoma （ grade Ⅲ）, 13 glioblastoma muhiforme （grade Ⅳ ）. The ADC values of the tumor core of low grade astrocytoma, anaplastic astrocytoma and glioblastoma muhiforme were （1.44 ±0.26）×10^-3, （0.98 ±0.22）×10-3 and（0.83 ±0.15）×10^-3mm^2/s respectively, and the rADC values were （1.91 ±0. 39）%, （1.34 ±0. 33）% and （ 1.06 ± 0. 20）% respectively. The EDC values were 0.26 ±0. 11,0. 39 ±0. 09 and 0.44 ±0.07 respectively, and the rEDC values were （0. 55 ±0. 20）%, （0. 81 ±0. 19）% and （0. 98 ±0. 16）% respectively. Significant differences of these values at the tumoral core were seen between different pathological grades of the astrocytic tumors （ F = 36. 189,31. 756, 19. 623 and 24. 760, P = 0. 000）. The ADC and rADC values of high-grade astrocytic tumors were （ 0. 89 ± 0. 19）×10^-3 mm^2/s and （ 1.17 ± 0. 28 ） % respectively, which were lower than those of low-grade astrocytic tumors （ t = 8. 332 and 7. 620, P = 0. 000） , while the EDC and rEDC values of high-grade tumors were 0. 42 ± 0. 08 and （0. 91 ± 0. 18 ）% respectively, being higher than those of low-grade tumors（ t

关 键 词：磁共振成像 弥散 星形细胞瘤 胶质母细胞瘤 

分 类 号：R739.4[医药卫生—肿瘤]