双螺旋CT门静脉血管造影最佳扫描层厚和螺距的研究  

Experimertal collimation and pitch for imaging portal venous system using double spiral computed tomographic angiography

作　　者：罗建光[1] 刘顾岗[1] 杨树仁[1] 杨东益[1] 沈树斌[1] 李德泰[1] 

机构地区：[1]湖南医科大学附属第二医院放射科

出　　处：《中华放射学杂志》1999年第5期341-343,共3页Chinese Journal of Radiology

摘　　要：目的评价双螺旋ＣＴ血管造影（ＳＣＴＡ）不同扫描层厚和螺距对门静脉成像质量的影响。方法将４个猪肝制成血管模型，分别以５种不同的螺距、层厚（ｍｍ）的组合形式扫描。Ａ组螺距为１．０，层厚２．５ｍｍ；Ｂ组螺距１．５，层厚２．５ｍｍ；Ｃ组螺距２．０，层厚２．５ｍｍ；Ｄ组螺距１．０，层厚５．０ｍｍ；Ｅ组螺距１．５，层厚５．０ｍｍ。所有原始图像均采用最大信号强度投影（ＭａｘＩＰ）法处理。分析模型血管分支的显示与层厚和螺距的关系。结果⑴在ＳＣＴＡ图像质量方面，Ａ、Ｂ组的效果均佳，优于Ｃ组，而Ｃ组优于Ｄ组，Ｄ组优于Ｅ组。⑵重建血管影像有放大。结论⑴双螺旋门静脉ＳＣＴＡ最佳扫描层厚为２．５ｍｍ、螺距为１．５；⑵层厚对ＳＣＴＡ图像质量的影响大于螺距；⑶ＳＣＴＡ的主要缺点是可能高估或低估血管狭窄程度。Objective To optimize parameters with double spiral computed tomographic angiography(SCTA) for visualization of portal veins. Methods 4 pig livers were scanned with five different parameters A, B, C, D, E, the pitchcollimation(mm) were 1.02.5, 1.52.5, 2.02.5, 1.05.0, and 1.55.0 respectively. All images were reconstructed with maximum intensity projection(MaxIP). The relationship of visualization of the model vessele branches with the collimation and pitch were analysed. Results (1) In regard to resolution of the constructed SCTA images, both A and B parameter combinations were good and superior to C, D and E. The images quality of E was the worst. (2) The reconstructed vessels were found to be somewhat amplified. Conclusions (1) The optimized collimation is 2.5 mm and pitch is 1.5 for portal vein imaging using SCTA with MaxIP algorithm. (2) The effect of collimation is greater than that of pitch on image quality of SCTA. (3) The main defect of SCTA is overestimation or underestimation of vessel stenosis.

关 键 词：门静脉造影术 血管造影 CT 对比研究 

分 类 号：R816.2[医药卫生—放射医学]