摘要
目的探讨在结直肠癌患者双源CT扫描和T分期评估中应用个体化剂量调节方案降低患者辐射剂量的可行性。方法随机分配40例于术前行双源CT低剂量扫描,应用电流自动调制装置(CareDose 4D)并依据身体质量指数(BMI)分级制定个体化剂量调节方案;另40例术前行常规MSCT扫描作为对照组。以术后病理分期作为金标准,分别计算普通CT扫描组和低剂量扫描组的敏感度和特异度,然后比较两组诊断正确率有无统计学差异。扫描时测定每位患者的辐射剂量,并计算其有效剂量,比较普通CT扫描组和低剂量扫描组患者有效剂量有无统计学差异。结果与术后病理学T分期比较,普通MSCT扫描组的准确度为93.75%,DSCT低剂量扫描组的准确度为92.5%,两组之间无统计学差异(t=0.81,P>0.05)。DSCT低剂量扫描组患者的平均有效剂量为3.12mSv,常规MSCT扫描组患者的平均有效剂量为6.44mSv,前者显著低于后者(t=2.566,P<0.05)。结论应用个体化剂量调节方案对结直肠癌患者进行双源CT低剂量扫描可在不影响T分期评估准确率的情况下显著降低患者辐射剂量。
Objective To evaluate the feasibility of low-dose dual-source CT undergoing individual adapted examination protocol in the preoperative T staging of cdorectal cancer. Methods Eighty patients with histological lyproven cdorectal cancer were enrolled. Half of them were randomly selected to he undertaken low-dose dual-source CT with individual adap- ted examination protocol. The other half, as a control group, were scanned normal multi-slice CT technique. Sensitivity and specificity of low-dose group and normal group relative to the pathologic staging were calculated respectively. Then diagnostic accuracy was statistically compared between two groups. CT dose index volume and dose-length product of pa- tients was measured, and effective dose was estimated and compared between two groups. Results The accuraeiy of nor- mal group and low-dose group was 93. 75%and 92.5% respectively. There were no statistical difference between them（ t = 0.81, P 〉0.05）. The average effective dose of normal group and low-dose group was 6.44 and 3.12, respectively. The latter was significantly lower than the former （ t = 2. 566, P 〈0.05）. Conclusion With individual adapted examination protocol in dual-source CT, the patient dose can be reduced significantly without affecting the accuracy in T-staging diagnosis of rectal cancer.
出处
《医学影像学杂志》
2012年第6期941-945,共5页
Journal of Medical Imaging
