低剂量多层螺旋CT在泌尿系结石中的初步应用

Preliminary application of low-dose multi-slice CT in investigating urinary calculi

目的:探讨低剂量多层螺旋CT(MSCT)在泌尿系结石诊断中的应用价值。方法:对69例可疑泌尿系结石的病例行腹部平片(KUB)和全腹部低剂量MSCT检查,分析两种检查方法诊断泌尿系结石的敏感性、特异性和准确性,并对两种方法检出结果作统计分析。记录低剂量MSCT扫描时权重CT剂量指数(CTDIw)。结果:KUB拟诊33例为阳性结石,36例阴性,其中共有47例得到证实,其敏感性为62%,特异性为89.5%,准确性为69.6%。MSCT共拟诊泌尿系结石51例,18例阴性,其中68例得到证实,其敏感性为100%,特异性为94.7%,准确性为98.6%。两种方法对泌尿系结石的检出率差异有统计学意义(χ2=13.1,P<0.01)。低剂量MSCT扫描时CTDIw平均为4.8mGy。结论:低剂量MSCT是一种敏感、安全的泌尿系结石检查方法,优于KUB平片。

Objective： To evaluate the low-dose multi-slice CT（MSCT） in investigating urinary calculi. Methods： Plain abdominal radiograph（KUB） film and low-dose MSCT scanning were performed in 69 cases with suspected urinary calculi, the sensitivity, specificity and accuracy of KUB and low-dose MSCT were calculated respectively, and a statistical analysis was made. Computed tomography dose index（CTDIw） of low-dose MSCT was recorded. Results： Thirty-three cases had positive findings and other 36 cases had negative findings in KUB group, 47 of 69 cases were proved by clinic or surgery. The sensitivity, specificity and accuracy of KUB were 62%, 89.5% and 69.6% respectively. Fifty-one cases had positive findings and 18 cases had negative findings in the MSCT group, 68 of 69 cases were proved by clinic or surgery. The sensitivity, specificity and accuracy of low-dose MSCT scanning were 100%, 94.7% and 98.6% respectively. There was significant difference between the two groups（X^2=13.1, P〈0.01）. The average CTDIw of low-dose MSCT was 4.8mGy. Conclusion： Low-dose MSCT is sensitive, safe and effective in investigating urinary calculi, and it is better than KUB.