CT ANGIOGRAPHY OF BRAIN USING ULTRAFAST CT : PHANTOM AND CLINICAL STUDY

在基础研究的基础上，我们用超高速CT对小血管CT血管成像的准确性进行了评估。制备内径分别为8 mm、6 mm和4 mm的血管模型，每条血管的狭窄程度分别为75%、50%和25%。血管内注入造影剂(碘帕咪醇300按1/24稀释，约380HU)。所用仪器为Lmatron C-150。采用层厚1.5 mm和3 mm的阶梯式容积扫描方式。获得最大密度投影(MIP)图像和三维(3D)图像。使用8 mm血管模型，所有狭窄节段在CT血管成像上都得到了准确的显示。所有血管中50%的狭窄节段被准确估计。然而，75%的狭窄节段在较小的血管中被轻微高估，而25%的狭窄节段在较小的血管中被略有低估。临床数据还不足以进行统计分析，但我们发现它在评估狭窄病变和相关的钙化动脉壁方面是有用的。

On the basic study, we evaluated the accuracy of CT angiography in small vessels using ultra-fast computed tomography. Vessel phantoms with inner diameters of 8 mm, 6 mm, and 4 mm were prepared with segments of 75%, 50%, and 25% stenosis in each vessel. The vessels were filled with contrast medium (Iopamidol 300 at 1/24 dilution, approximately 380 HU).The apparatus used was an lmatron C-150. The step volume scan mode was used with slice thickness of 1.5 mm and 3 mm. Both maximum intensity projection (MIP) images and three-dimensional (3D) images were obtained. Using the 8 mm vessel phantom, all stenotic segments were accurately visualized on CT angiography. The 50% stenotic segments were accurately estimated in all vessels. However, the 75% stenotic segments were slightly overestimated in smaller vessels, and the 25% stenotic segments were sligtly underestimated in smaller vessels.Clinical data are not yet sufficient for statistical analysis, but we found its usefulness in the evaluation of not only stenotic lesions but also associating calcified arterial walls.