Department of Radiological Sciences, University of Messina, Policlinico G. Martino, Via Consolare Valeria 1, 98100, Messina, Italy.
AJR Am J Roentgenol. 2011 Jun;196(6):1408-14. doi: 10.2214/AJR.10.4505.
The purpose of our study was to evaluate the value of dual-source dual-energy CT with colored iodine overlay for detection of endoleaks after endovascular abdominal aortic aneurysm repair. We also calculated the potential dose reduction by using a dual-energy CT single-phase protocol.
From November 2007 to November 2009, 74 patients underwent CT angiography 2-7 days after endovascular repair during single-energy unenhanced and dual-energy venous phases. By using dual-energy software, the iodine overlay was superimposed on venous phase images with different percentages ranging between 0 (virtual unenhanced images) and 50-75% to show the iodine in an orange color. Two blinded readers evaluated the data for diagnosis of endoleaks during standard unenhanced and venous phase images (session 1, standard of reference) and virtual unenhanced and venous phase images with colored iodine overlay images (session 2). We compared the effective dose radiation of a single-energy biphasic protocol with that of a single-phase dual-energy protocol. The diagnostic accuracy of session 2 was calculated.
The mean dual-energy effective dose was 7.27 mSv. By using a dual-energy single-phase protocol, we obtained a mean dose reduction of 28% with respect to a single-energy biphasic protocol. The diagnostic accuracy of session 2 was: 100% sensitivity, 100% specificity, 100% negative predictive value, and 100% positive predictive value. Statistically significant differences in the level of confidence for endoleak detection between the two sessions were found by reviewers for scores 3-5.
Dual-energy CT with colored iodine overlay is a useful diagnostic tool in endoleak detection. The use of a dual-energy single-phase study protocol will lower radiation exposure to patients.
本研究旨在评估双源双能 CT 彩色碘覆盖技术在血管内腹主动脉瘤修复术后检测内漏中的应用价值。我们还计算了使用双能 CT 单相方案的潜在剂量降低。
2007 年 11 月至 2009 年 11 月，74 例患者在血管内修复后 2-7 天行 CT 血管造影，采用单能非增强期和双能静脉期。使用双能软件，将碘覆盖叠加在静脉期图像上，百分比范围在 0（虚拟非增强图像）至 50-75%，以橙色显示碘。两位盲法读者评估标准非增强和静脉期图像（第 1 期，参考标准）和虚拟非增强和彩色碘覆盖静脉期图像（第 2 期）的数据，以诊断内漏。我们比较了单相双能方案和单相单能方案的有效剂量辐射。计算第 2 期的诊断准确性。
双能有效剂量的平均值为 7.27mSv。使用单相双能方案，与单相双能方案相比，平均剂量降低 28%。第 2 期的诊断准确性为：100%的敏感度、100%的特异度、100%的阴性预测值和 100%的阳性预测值。两位审阅者发现，在对 3-5 分的内漏检测置信度水平方面，两个时期之间的差异有统计学意义。
彩色碘覆盖的双能 CT 是检测内漏的一种有用的诊断工具。使用双能单相研究方案将降低患者的辐射暴露。
