Onoda Hiroshi, Ueno Hiroshi, Hashimoto Masahiko, Kuwahara Hiroyuki, Sobajima Mitsuo, Kinugawa Koichiro
Second Department of Internal Medicine, University of Toyama.
Department of Radiology, University of Toyama.
Int Heart J. 2019 Sep 27;60(5):1091-1097. doi: 10.1536/ihj.18-693. Epub 2019 Sep 4.
Low-voltage computed tomographic angiography (CTA) is a highly effective technique to reduce contrast media volume. We sought to examine the suitability of low tube voltage CTA with a reduced contrast media volume protocol using third-generation 192-slice dual-source CT in patients undergoing transcatheter aortic valve implantation (TAVI). CTA was performed to aid TAVI planning for 40 consecutive patients with severe aortic stenosis. For the first 10 patients (120/100 kV group), we used a conventional tube voltage combined CTA protocol (an ECG-gated helical scan; 120 kV, non-gated helical scan; 100 kV). For the subsequent 30 patients (70-kV group), we adopted a low tube voltage CTA protocol. We evaluated vascular attenuation, image noise, contrast-to-noise ratio (CNR), and renal function. The mean contrast media (CM) volume was 77.7 ± 17.7 mL in the 120/100-kV group and 30.9 ± 6.3 mL in the 70-kV group (P < 0.001). In the images of the aortic valve complex, the mean attenuation was not significant difference for both groups. In the images of the aorto-femoral arteries, mean attenuation was > 250 Hounsfield Units and CNR was > 10 in all vascular segments for both groups. There was no significant difference in the change of renal function in the 70-kV group, but renal function in the 120/100-kV group decreased within 1-3 months after CTA. Low tube voltage CTA using third-generation dual-source CT is suitable to assess procedural planning for TAVI. This approach maintains image quality and reduces the required CM volume.
低电压计算机断层血管造影（CTA）是一种减少造影剂用量的高效技术。我们试图在接受经导管主动脉瓣植入术（TAVI）的患者中，使用第三代192层双源CT，研究采用减少造影剂用量方案的低管电压CTA的适用性。对40例连续性重度主动脉瓣狭窄患者进行CTA检查以辅助TAVI规划。对于前10例患者（120/100 kV组），我们采用传统管电压联合CTA方案（心电门控螺旋扫描；120 kV，非门控螺旋扫描；100 kV）。对于随后的30例患者（70 kV组），我们采用低管电压CTA方案。我们评估了血管衰减、图像噪声、对比噪声比（CNR）和肾功能。120/100 kV组的平均造影剂（CM）用量为77.7±17.7 mL，70 kV组为30.9±6.3 mL（P<0.001）。在主动脉瓣复合体图像中，两组的平均衰减无显著差异。在主动脉-股动脉图像中，两组所有血管节段的平均衰减均>250亨氏单位，CNR均>10。70 kV组肾功能变化无显著差异，但120/100 kV组在CTA后1 - 3个月内肾功能下降。使用第三代双源CT的低管电压CTA适用于评估TAVI的手术规划。这种方法可保持图像质量并减少所需的CM用量。
