iDose迭代重建算法对上腹部CT图像质量的影响  

The effect of iDose iterative reconstruction algorithm on the image quality of upper abdomen CT scan

作　　者：袁肖娜 高知玲[2] 朱凯[2] 马文东[2] 陈勇[2] 

机构地区：[1]宁夏医科大学,宁夏银川750004 [2]宁夏医科大学总医院放射科

出　　处：《实用放射学杂志》2016年第1期102-106,共5页Journal of Practical Radiology

基　　金：宁夏留学人员资助项目[2013];宁夏医科大学特殊人才肩动基金项目[XT201417].

摘　　要：目的 比较不同水平的iDose迭代重建算法对上腹部CT增强扫描门静脉期图像质量的影响，获取本组图像质量相对较好的iDose迭代水平。方法 采用256层螺旋CT扫描仪对60例患者行4期上腹部CT增强扫描，对门静脉期的图像采用滤波反投影（FBP）、iDose1、iDose3、iDose5共4种方式的重建，比较不同重建方式下图像客观质量，包括噪声、信噪比（SNR）、对比噪声比（CNR），以及主观质量（噪声、锐利度、对比度、伪影、细小结构的清晰度）的差异。结果 4组图像的客观质量差异均有统计学意义（P〈0.05），iDose各组图像的客观噪声均低于FBP组,而SNR、CNR均高于FBP组（P〈0.05）,iDose5组的SNR、CNR最高。与FBP组相比，iDose各组图像的主观噪声更低，锐利度、对比度及细小结构清晰度更好（P〈0.05），4组图像的伪影差异无统计学意义（P〉0.05）。iDose3水平重建后图像的总体指标最好。结论 常规上腹部CT增强扫描时，应用 iDose迭代算法重建后图像的噪声降低，总体质量提高。Objective To evaluate the effect of different levels of iDose iterative reconstruction algorithm on image quality of the portal vene of upper abdomen enhancemed CT scans and determine the level of iDose for relatively good image quality in our study. Methods A total of sixty patients who underwent four-pbase contrast-enhanced upper abdomen CT with 256 slice spiral CT scan were included in this study. CT images of the portal phase were reconstructed with the use of filtered back projection （FBP） protocol and three level iDose protocols （iDosel ,iDose3, iDose5）, objective image quality including noise, signal-to noise ratio（SNR） and con- trast-to-noise ratio（CNR}, and subjective image quality including image noise, sharpness, contrast, artifact and the visibility of mini mal structure were respectively compared between the four groups. Results There were significant differences of objective image quality between four groups（P〈0.05）. For objective image, noise on iDose group was lower than that on FBP group, but signal to noise ratio and contrast to-noise ratio on iDose group was higher than that on FBP group, the SNR and CNR were the highest in iDose5 group. For the subjective image, noise, sharpness, contrast and the visibility of small structures tended to be better for iDose groups when compared with FBP groups（P〈0.05）, no significant difference of artifact was found for four groups（P〉0.05）. The parameters for image quality were the highest with iDose level 3. Conclusion iDose iterative reconstruction can reduce image noise and improve image quality when performing upper abdomen CT scan with a usual dose.

关 键 词：上腹部 计算机体层成像 iDose迭代重建算法 滤波反投影 重建算法 图像质量 

分 类 号：R323.3[医药卫生—人体解剖和组织胚胎学] R814.42[医药卫生—基础医学]