表观弥散系数在原发中枢神经淋巴瘤与胶质母细胞瘤鉴别诊断中的作用

目的探讨表观弥散系数(apparent diffusion coefficient,ADC)在原发中枢神经淋巴瘤(primary central nervous system lymphoma,PCNSL)与胶质母细胞瘤(glioblastoma,GBM)磁共振鉴别诊断中的作用。材料与方法回顾性分析经手术和病理证实的17例PCNSL及24例GBM(WHOⅣ级)MRI形态学表现、增强后的强化方式以及对两种疾病的ADC最大值、最小值和平均值和病变处与正常脑实质的表观弥散系数值之比(apparent diffusion coefficient ratio,r ADC)分别进行定量分析。结果 PCNSL与GBM平均年龄并没有显著差异[(55.3±19.1)岁和(58.2±15.1)岁]。PCNSL的MRI特征与GBM相比,包括:病变数量多发(70.6%和4.2%,P0.001),明显均匀强化(82.4%和4.2%,P0.001)显然更加常见;而GBM与PCNSL相比,囊变、坏死、出血(100%和47.1%,P0.001)显示的更加明显;PCNSL比GBM肿瘤实质部分ADC平均值低[(0.86±0.34)×10~3 mm~2/s和(1.47±0.57)×10~3 mm~2/s,P=0.019];PCNSL比GBM肿瘤实质部分r ADC值低(1.16±0.63、1.83±0.38,P=0.020)。结论这个研究证实从MRI形态学表现、强化方式及其测量得到的ADC平均值及r ADC值是完全可以去鉴别PCNSL与GBM。

The value of apparent diffusion coefficient in the differentiating diagnosis between primary central nervous system lymphoma and glioblastoma

Objective: To investigate the value of apparent diffusion coefficient in the differentiating diagnosis between primary central nervous system lymphoma and glioblastoma. Materials and Methods: This study retrospectively analyzed 17 cases of primary central nervous system lymphoma and 24 cases of glioblastoma (WHOⅣ grade) confirmed by surgery and pathology. The morphological features of MRI, the enhancement, the minimum-, mean-, and maximum apparent diffusion coefficient (ADC) (ADCmin, ADCmean, ADCmax) on the two diseases and the ratio of apparent diffusion coefficient value (rADC) of lesions and normal brain parenchyma were quantitatively analyzed. Results: The mean age at PCNSL and GBM did not differ significantly [(55.3±19.1) years and (58.2±15.1) years]. The MRI features of PCNSL compared with GBM include multiple lesions (70.6% vs 4.2%, P<0.001), significantly uniform enhancement (82.4% vs 4.2%, P<0.001) was apparently more common; whereas GBM showed more pronounced cystic degeneration, necrosis, and hemorrhage (100% vs 47.1%, P<0.001) compared with PCNSL. PCNSL have lower ADCmeanvalue [(0.86 ± 0.34)× 103mm2/s and (1.47 ± 0.57)×103mm2/s, P=0.019) than those of GBM. The ratio ADC value of PCNSL were higher than those of GBM (1.16±0.63, 1.83 ± 0.38, P=0.020). Conclusions: This study confirms that the morphologic appearance, enhancement modalities, and their measured ADCmeanvalues and their ratios are entirely valid for the identification of PCNSL and GBM.