星形细胞瘤磁共振弥散加权成像与肿瘤细胞密度的相关性研究

Correlation between magnetic resonance diffusion weighted imaging and cell density in astrocytoma

目的运用磁共振(MR)弥散加权成像技术评估近似弥散系数(ADC)在星形细胞瘤的细胞密度和病理分级中的作用。方法术前进行磁共振成像(MRI)和MR弥散加权成像检查且经手术病理证实的34例星形细胞瘤患者,其中低级别(Ⅰ、Ⅱ级)26例,高级别(Ⅲ、Ⅳ级)8例。在MRI上计算瘤体的ADC值,运用AdobePhotoshop7.0.1软件分析星形细胞瘤的细胞密度,用SPSS10.0软件对资料进行处理。结果高级别星形细胞瘤的ADC为(7.34±2.95)×10-4mm2/s,低级别星形细胞瘤的ADC为(13.76±3.31)×10-4mm2/s,两者之间差异有统计学意义(t=4.91,P<0.001);高级别星形细胞瘤的细胞密度为(19.81±9.73)%,明显大于低级别星形细胞瘤的细胞密度(4.74±2.96)%(t=4.32,P=0.003);星形细胞瘤的ADC值与细胞密度呈显著负相关(r=-0.535,P=0.001)。结论星形细胞瘤的ADC值与肿瘤细胞密度呈显著负相关;MR弥散加权成像具有对星形细胞瘤的良、恶性程度进行预测的潜能。

Objective To evaluate the apparent diffusion coefficients (ADC) in magnetic resonance diffusion weighted imaging with echo-planar technique in depicting the tumor cellularity and grading of astrocytoma. Methods Thirty-four astrocytoma patients including 18 male and 16 female with age from 10 to 73 years(mean 38.4 years) were examined by MRI and eventually proved by surgical resection and pathological examination. Of them, 26 had low-grade (gradeⅠ,Ⅱ) astrocytoma and 8 high-grade ( grade Ⅲ,Ⅳ) astrocytoma. ADC value of astrocytoma was determined on magnetic resonance diffusion weighted images. Cellularity of the astrocytoma was analyzed using Adobe Photoshop 7.0.1 software. Results The mean ADC value (in units of 10^-4 mm2/s) of the high-grade astrocytomas (7.34±2.95) was significantly lower than that of the low-grade astrocytomas (13.76±~3.31) (t=4.91,P<0.001). The mean cellularity of the high-grade astrocytomas (19.81±9.73)% was significantly higher than that of the low-grade astrocytomas (4.74±2.96)% (t=4.32,P=0.003). ADC value of the astrocytoma was significantly and negatively correlated with its cellularity (r=-0.535,P=0.001). Conclusion ADC value of astrocytoma is significantly and negatively correlated with its cellularity. Magnetic resonance diffusion weighted imaging may well be highly potential in predicting the degree of astrocytoma.