脑CT血管造影及其临床应用

Technique for Cerebral CT Angiography and Clinical Application

本文介绍一种用螺旋ＣＴ行脑血管造影技术。经验表明，此技术简便易行，几无创伤，且可同时显示颈动脉和基底动脉系统，可作为脑血管造影的筛选工具，对有些病例还能代替常规的创伤性脑血管造影。本文对下述三个技术要点进行了讨论：①螺距：单螺旋ＣＴ的螺距不应大于１，以０．８～１．０较理想，双螺旋ＣＴ的螺距不能大于２，以１．３～１．８为宜；②选择重建方式的重要性：ＭＩＰ法能较好显示脑血管的狭窄，阻塞及充盈缺损，而３－Ｄ表面成象法适合显示血管的管腔轮廓及其与骨性表面标志的三维关系；③ＭＩＰ横轴面上重建的血管图像较纵轴重建的血管图像质量好，因此，我们必须尽可能使扫描断面与感兴趣血管的长轴平行。

This article introduced a technique for obtaining cerebral angiography by means of spiral CT. Our experience show that this technique by it's easy handling, minimal invasiveness and excellent visualization of the carotid and basilar arteries at the same time may prove useful as a screening tool or replacement for conventional angiography in some patients. The following technical points were disscussed: ①Pitch: For the single spiral CT, the value of pitch must be less than 1.0. The recommended pitch value is 0.8-1.0. For the double spiral CT, it must be less than 2.0. The recommend pitch value is 1.3-1.8.②Importance of selecting reconstruction method: MIP Image provide good depiction of vascular stenosis, dilatation and filling defects, 3D surface Image suit for depiction of vascular luminal contour and 3D relationship with its adjacent bone marters.③The vascular image quality on the transversal axial view of MIP is better than on the longitudinal view. Therefore, we must select scan slices to parallel with the long axis of the interesting vessels as well as possible.