利用肺脏模型评价CT测量胸腔积液量准确性的研究

目的评价CT测算胸腔积液量的准确性。方法(1)采用GE-sytec4000i全身CT扫描系统,对注水肺脏模型进行扫描,选取右侧肺脏共作15次测量。(2)由一名熟练的CT操作人员在积液最明显的一层上用轨迹手工圈划出积液的完整轮廓,预设感兴趣区的CT值上下限范围0~20 Hu,采用计算机体积测算功能,计算出各层满足上述要求的感兴趣区图像总体积。结果肺脏模型体积CT测值与实际注水量关系呈直线趋势,R2=1.000。回归系数t检验的t值=681.077,P=0.0001(P<0.001),故可认为肺脏模型体积CT测值与实际注水量之间有直线关系;直线回归方程为:Y=-0.238+0.999X。肺脏模型体积的标准差为893.27504,实际注水量的标准差为894.42719。肺脏模型体积CT测值与实际注水量的相关分析表明,肺脏模型体积CT测值与实际注水量高度相关。结论CT能够准确测量胸腔积液量,它可替代传统X线的粗略估算,是胸腔积液测算的客观准确方法。

Accuracy of Hydrothorax Volume Measurement by CT's Volume Measuring Function

Objective To evaluate the accuracy of hydrothorax volume by computerized tomography(CT).Methods(1) Water-perfused lung model was scanned by systemic CT scanning(GE-sytec4000i),which measured the right lung of the model for 15 times.(2) A skilled CT operator drew the whole contour line on the layer with the clearest hydrothorax with manual tracks.The prearranged interesting area CT value's upper and lower limit was 0-20 Hu.The total interesting area imaging volume was calculated using the computer's volume measuring function.Results A linear trend existed between the lung model's CT volume value and the actually perfusing volume's scatterplot(R2=1.000),which indicated a linear correlation with a 681.077 of t value in regression coefficient t test(P=0.000 1,P<0.001;regression equation: Y=-0.238 0.999X).The standard deviation was 893.275 04(lung model volume) or 894.427 19(actually perfusing volume).The correlation analysis between the lung model's CT volume value and the actually perfusing volume suggested that they were highly correlative,i.e.there was no significant difference(P<0.001).Conclusion The volume of hydrothorax can be accurately measured by CT which may replace traditional X-ray rough estimation.