MRI动态增强对鼻咽癌及其放疗后改变的诊断价值

目的 探讨MRI动态增强对鼻咽癌及其放疗后改变的诊断价值.方法 收集原发或放疗后的鼻咽癌患者57例,将其分为未经治疗组、放疗后纤维化组及复发组,所有病例治疗前的病理诊断均为鳞状细胞癌.采用Flash序列获取三组病例动态增强的时间-信号强度曲线（TIC）并对其达峰时间（TTP）、曲线最大斜率（Slopemax）、曲线下面积（AUC）三个参数进行统计学分析,获取参数伪彩图.结果 3组病例MRI动态增强TTP、Slopemax、AUC的均值行组间两两比较,未经治疗组和纤维化组的3个参数差别均有统计学意义,而纤维化组与复发组仅Slopemax均值存在统计学差异.参数伪彩图可直观地显示肿瘤或放疗后纤维化组织相应的血流灌注情况.结论 动态增强TIC的类型、Slopemax有助于鉴别鼻咽癌复发和纤维化.

Value of dynamic contrast-enhanced MRI for diagnosing and follow-up of nasopharyngeal carcinoma

Objective To investigate the value of dynamic contrast-enhanced MRI for diagnosing and follow-up of nasopharyngeal carcinoma （NPC）. Methods A prospective study were performed on 57 consecutive patients with histologically proven NPC from November 2004 to December 2008. The patients were divided into three groups of untreated NPC, radiation-induced nasopharyngeal fibrosis, and recurrent NPC after radiotherapy. MRI appearances and the dynamic contrast-enhancement parameters including time to peak （TTP）, maximum slope （Slopemax）, and area under the time-intensity curve （AUC） were analyzed. Results There was significant difference in the TIP, Slopemax, and AUC between the pre-treatment and nasopharyngeal fibrosis groups. Only the Slopemax was significantly different between the recurrent NPC and nasopharyngeal fibrosis groups. Color display of the three dynamic contrast-enhancement parameters can visually demonstrate the perfusion of tumor or fibrosis after radiotherapy, Conclusion Dynamic contrast-enhanced MRI can distinguish radiation-induced fibrosis from recurrent NPC.