鼻咽癌放疗后局部复发和纤维变的动态CT增强特征

Dynamic enhanced spiral CT characteristics of recurrent nasopharyngeal carcinoma and radiofibrosis

目的探讨鼻咽癌放疗后局部复发和纤维变的螺旋ＣＴ动态增强特征。方法放疗后纤维变组（ＲＦ组）５０例，复发组（ＲＮＰＣ组）４６例。先平扫，然后选择兴趣区行同层动态增强扫描。采用ＥＬＳＣＩＮＴＣＴＦＬＡＳＨ双螺旋ＣＴ扫描机，自动压力注射器注药。分别测量两组平扫与增强后不同时刻的ＣＴ值，进行统计学处理，并描绘密度时间曲线。结果ＲＦ组于增强后２１０秒时达峰值，其动态增强曲线特征呈缓升—缓降型。ＲＮＰＣ组于增强后１５０秒时达峰值，其动态增强曲线特征呈速升—缓升—缓降型。注射造影剂后４０～３００秒期间，ＲＦ组与ＲＮＰＣ组间各对应时刻点ＣＴ值均数差异均有显著性（Ｐ＜０．００１），ＲＮＰＣ组明显高于ＲＦ组。结论ＲＦ与ＲＮＰＣ的螺旋ＣＴ动态增强曲线特征及病变区ＣＴ值的明显差异。

Objective To study the characteristics of dynamic enhanced density time curves of recurrent nasopharyngeal carcinoma(RNPC) and radiofibrosis(RF) in spiral CT. Methods Fifty cases of RF and 46 cases of RNPC were examined both before and after contrasting in spiral CT. The CT values of the regions of interest(ROI) at various acquisition time (0, 20, 30, 40,50, 60, 90, 120, 150, 180, 210, 240, 270, and 300 sec after the beginning of the contrast injection) were collected. The difference in CT value of various acquisition time was analysed statisticaly and the dynamic enhanced density time curves were established. Results The typical curve in RF group was a slowly ascending slowly descending one.Its peak CT value as seen at 210 sec postcontrast and measured 60.1±2.57 Hu. That of the RNPC was of rapidly ascending slowly ascending slowly descending one. Its peak CT valne was seen at 150 sec postcontrst and measured 75.4±7.2 Hu. The differences of CT values were significant between RNPC and RF from 40 to 300 sec postcontrast ( P <0.001). Conclusion The different characteristics of the dynamic enhanced desity time curves and CT values of the ROI may provide important informations for differential diagnosis of RNPC and RF.