应用彩色多普勒闪烁伪像和CT分析尿酸结石和胱氨酸结石成分的实验研究

Value of color Doppler twinkling artifact and CT in distinguishing uric acid stones from cystine stones： an experimental study

目的 定量分析彩色多普勒闪烁伪像和CT区分尿酸结石和胱氨酸结石成分并预测尿酸结石的应用价值.方法 相同体外实验条件下,分别对尿酸和胱氨酸人工结石行彩色多普勒超声扫查和CT扫描,测量闪烁伪像宽度（TAW）、长度（TAL）和强度（TAD以及CT值,分析两种成分结石模型测量参数的差异性并绘制ROC曲线.结果 尿酸和胱氨酸人工结石间的TAW、TAL、TAI和CT值差异均有统计学意义（P均＜0.05）.ROC曲线分析显示,以上述测量参数为标准判断尿酸结石成分时,CT值的曲线下面积最大（0.936）,TAI次之（0.817）,二者比较差异有统计学意义（Z=2.308,P=0.021）;若二者联合,对尿酸结石成分的诊断准确性可提高至98％.结论 彩色多普勒闪烁伪像和CT均是区分尿酸结石和胱氨酸结石成分的可靠手段,有望为临床应用影像学技术诊断尿酸结石提供参考.

Objective To quantitatively analyze the value of color Doppler twinkling artifact and CT in distinguishing urinary stone composition of uric acid from that of cystine,and to assess the ability of color Doppler twinkling artifact and CT to diagnose urinary stone composition of uric acid.Methods Artificial stones made of uric acid and cystihe were inserted in porcine kidneys respectively.Color Doppler ultrasound and CT scanning were performed in vitro and twinkling artifact videos were recorded.The CT attenuation value,the width and length of twinkling artifact （TAW,TAL） were measured.The color pixels representing twinkling artifact intensity （TAI） were calculated.The differences between artificial cystine and artificial uric acid stones in TAW,TAL,TAI and CT attenuation value were compared.The receiver operating characteristic （ROC） curve was used to assess the ability of TAW,TAL,TAI and CT attenuation value to diagnose urinary stone composition of uric acid.Results The TAW [（4.16 ± 1.54）mm vs （4.97 ± 1.93）mm],TAL[（3.75 ± 1.05）mm vs （5.12 ± 2.51）mm] and TAI [（3 005.50 ± 812.33） vs （5 433.86±2 505.81）] of artificial cystine stones were less than those of artificial uric acid stones while the CT attenuation value of artificial cystine stones [（573.75 ± 110.10）HU vs （364.09 ± 67.28）HU] were greater （P 〈0.05）.The ROC curve was displayed to diagnose urinary stone composition of uric acid,and the area under curve of CT attenuation value was bigger than that of TAI （0.936 vs 0.817,Z =2.308,P =0.021）.Combination of color Doppler twinkling artifact and CT value would dramatically increase the diagnostic accuracy to 98%.Conclusions Both color Doppler ultrasound and CT were reliable examinations for distinguishing urinary stone composition of cystine from that of uric acid.Combination of color Doppler ultrasound and CT would be good references to diagnose urinary stone composition of uric acid.