Suzuki Shigeru, Furui Shigeru, Kuwahara Sadatoshi, Kaminaga Tatsuro, Yamauchi Teiyu, Kawasaki Tsutomu, Konno Kumiko, Kozuma Ken, Isshiki Takaaki
Department of Radiology, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan.
J Comput Assist Tomogr. 2007 May-Jun;31(3):414-21. doi: 10.1097/01.rct.0000243446.95491.29.
To assess the effect of tube voltage on the in-stent visibility of coronary stents in vitro on computed tomography (CT) angiography.
A total of 6 vascular models (3 models without stenosis and 3 with stenosis) using 3 kinds of stent (Bx Velocity, Express2, and Driver) with an inner diameter of approximately 3.5 mm and filled with contrast material (CT attenuation, 450 Hounsfield units) were scanned by means of a 16-detector row CT. We assessed the visual stenosis evaluation and inhomogeneity of stent lumen in 4 orientations (0-, 30-, 60-, and 90-degree angles) relative to the z-axis of the scanner using 3 imaging techniques (120-kV tube voltage using a medium convolution kernel, 120-kV tube voltage using a convolution kernel for bone, and 140-kV tube voltage using a convolution kernel for bone). Statistical analysis involved F test with a statistical significance of P < 0.05.
The convolution kernel for bone made it easier to evaluate the stenosis inside the stents, although it increased the luminal inhomogeneity significantly (Bx Velocity and Express2, P < 0.005; Driver, P < 0.05). The luminal inhomogeneity tended to increase as the strut diameter and the weight per unit length increased. Using 120-kV tube voltage, the luminal inhomogeneity inside the stents was at the minimum in the angle of 0 degree relative to the z-axis, and at the maximum in the angle of 90 degrees, except for Driver. The 140-kV tube voltage was effective for the improvement of luminal inhomogeneity and visibility of in-stent stenosis compared with the 120-kV tube voltage.
The in-stent visibility of coronary stents on CT angiography can be improved by the use of 140-kV tube voltage with the convolution kernel for bone.
评估管电压对冠状动脉支架在体外计算机断层扫描（CT）血管造影中支架内显影的影响。
使用16排CT对6个血管模型（3个无狭窄模型和3个有狭窄模型）进行扫描，这些模型使用3种内径约为3.5 mm的支架（Bx Velocity、Express2和Driver），并填充有对比剂（CT衰减值为450亨氏单位）。我们使用3种成像技术（使用中等卷积核的120 kV管电压、使用骨卷积核的120 kV管电压和使用骨卷积核的140 kV管电压），在相对于扫描仪z轴的4个方向（0°、30°、60°和90°角）上评估支架内狭窄的视觉评估和支架管腔的不均匀性。统计分析采用F检验，统计学显著性为P < 0.05。
骨卷积核虽然显著增加了管腔不均匀性（Bx Velocity和Express2，P < 0.005；Driver，P < 0.05），但使评估支架内狭窄更容易。随着支架支柱直径和单位长度重量的增加，管腔不均匀性有增加趋势。使用120 kV管电压时，除Driver支架外，相对于z轴，支架内管腔不均匀性在0°角时最小，在90°角时最大。与120 kV管电压相比，140 kV管电压对改善管腔不均匀性和支架内狭窄的显影有效。
使用140 kV管电压和骨卷积核可提高冠状动脉支架在CT血管造影中的支架内显影。
