鼻咽癌放疗后早期放射性脑损伤的磁共振扩散加权成像研究

Diffusion weighted MR imaging study on radiation induced of the brain after nasopharyngeal carcinoma radiotheraphy

目的：探讨磁共振扩散加权成像（DWI）在观察鼻咽癌患者放疗后早期放射性脑损伤方面的价值。方法选取健康志愿者20名，男性10名，女性10名。年龄24-65岁，平均年龄为（43±4）岁。20例鼻咽癌患者，男性11例，女性9例。年龄27-78岁，平均年龄为（50±5）岁。所有健康志愿者均行磁共振成像（MRI）常规平扫及DWI成像，DWI成像时b值分别采用0和1000 s/mm2。结果健康志愿者双侧颞叶的表观弥散系数（ADC）值与鼻咽癌患者放疗前的双侧颞叶的ADC值比较差异无统计学意义。鼻咽癌患者放疗前的双侧颞叶的ADC值与首次放疗后3 d及放疗后3个月双侧颞叶白质的ADC值之间差异有统计学意义，放疗后6个月、12个月及18个月时的双侧颞叶的ADC值与放疗前比较差异无统计学意义。结论磁共振DWI能够反映鼻咽癌放疗后放射性脑损伤的病理变化，是一种能够发现早期放射性脑损伤的影像学诊断方法。

Objective To evaluate the changes of diffusion in temporal lobe injury following radiotherapy for nasopharyngeal carcinoma （NPC）. Methods Selected 20 healthy volunteers as control group. Twenty cases of post-radiotherapy were with NPC. All of them were examined with routine MRI and diffusion weighted imaging （DWI） and measured the ADC values of temporal lobe, the averages of ADC value between groups were compared. Results The ADC values of the three days of post-radiotherapy group and the three months of post-radiotherapy group decreased than the control group and the pre-radiotherapy group. But six months of the post-radiotherapy group, the 12 months of post-radiotherapy group and the 18 months of post-radiotherapy group have not statistical significance with the control group and the pre-radiotherapy group. Conclusion DWI is provided an opportunity that radiation injures are detected in earlier period and management in time.