摘要
目的 分析并评价CT仿真内窥镜 (CTVE)在人体各部位临床应用的成像质量及其影响因素。方法 根据阈值模式将 143例CTVE成像分为 2大类 :低密度管腔CTVE(12 0例 ,包括自然充气管腔及被动充气管腔 )及高密度管腔CTVE(2 3例 )。应用 4级评分法评价 3组管腔CTVE图像在诊断可信性、伪影及图像总体质量之间的差异。统计方法应用非参数秩和检验 ,3组之间的总体差异用kruskalWallis检验 ,组与组之间的差异用WilcoxonW检验。结果 3组管腔CTVE图像的诊断可信性(χ2 =3.4,P >0 .0 5 )及图像总体质量 (χ2 =2 7.0 ,P >0 .0 5 )均无显著性差异 ,但两两比较 ,自然充气管腔CTVE的图像总体质量好于被动充气管腔 (Z =- 2 .4,P <0 .0 5 )。 3组管腔CTVE图像所见的伪影在总体上 (χ2 =2 7.0 ,P <0 .0 5 )及组与组之间 (Z =- 5 .2 2～ - 2 .2 5 ,P <0 .0 5 )均存在显著性差异 ,以高密度管腔的伪影最多 ,伪影等级最高 (2 0± 0 8)。常见的伪影与呼吸等运动、螺旋CT扫描参数选择不当及阈值调节不当等因素有关。结论 阈值的选择是影响CTVE图像质量的重要因素 ,多数CTVE图像上的伪影容易辨认 。
Objective To analyze and evaluate the image quality and the impact factors of CT virtual endoscopy (CTVE) in the application of various body parts. Methods CTVE images from 143 patients were classified into 2 types according to the chosen threshold: low attenuation lumen (including natural air filled and artificially air filled lumina) and high attenuation lumen. A 4 point scale was used to evaluate the differences of diagnostic confidence, artifacts, and overall image quality rating between both kinds of lumina. Results There was no statistically significant differences in diagnostic confidence of CTVE images among 3 kinds of lumina, but the image quality of CTVE of natural air filled lumen was better than that of artificially air filled lumen ( P <0.05), and was similar with that of high attenuation lumen ( P >0.05). There was a significant difference in artifact rating of CTVE images among three kinds of lumina with the most artifacts seen on images of high attenuation lumen. Common artifacts observed on the CTVE images were attributed to patient motion artifacts such as respiration, inappropriate choice of spiral CT scanning parameters, and improper modification of thresholds. Conclusion The threshold setting was one of the most important factors impacting the image quality of CTVE images, and most artifacts seen on the CTVE images were easily recognized on the basis of their characteristic appearance, and did not influence the diagnostic information heavily.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2000年第11期765-769,共5页
Chinese Journal of Radiology
关键词
CT仿真内窥镜成像
质量分析
临床应用
Tomography,X-ray computed
Image processing,computer assisted
Quality control
