摘要
目的探讨新一代自适应迭代重建-V(ASIR-V)不同重建级别对低剂量CT图像质量的影响及最佳重建级别。方法选取临床需要进行胸腹部增强CT扫描的患者96例,门静脉期扫描选择能谱序列,图像后处理均采用ASIR-V技术,并设置6个不同重建级别(0%、20%、40%、60%、80%、100%)。测量肝脏、脾脏、肾脏、竖脊肌及脂肪的CT和SD值并计算信噪比(SNR)、对比噪声比(CNR)和图像噪声(SD);图像质量按1~5分予以主观评分。采用SPSS 22.0软件进行统计学分析,P<0.05为差异有统计学意义。结果1)客观评价:肝脏、脾脏、肾脏实质不同重建级别的CNR、SNR及SD值差异均有统计学意义。随着重建级别的增加,图像SNR、CNR值逐渐增大,噪声SD逐渐降低,图像质量提高;2)主观评价:ASIR-V 0%、100%重建的图像质量最差,60%~80%范围图像质量评分最高;40%和100%、60%和80%组间对比差异无统计学意义,余各组间差异均具有统计学意义。结论综合主客观评价,设置ASIR-V重建级别能够不同程度优化低剂量扫描图像质量,过度迭代图像蜡样质感较严重,组织对比明显降低,细节显示不清,其中以60%~80%范围重建级别最佳。
Objective To investigate the main and objective evaluation of CT images of different reconstruction levels by adaptive iterative reconstruction-V(ASIR-V),and to explore the best reconstruction level of ASIR-V to optimize CT image quality.Methods 96 patients who clinically needed enhanced CT scan of the upper abdomen were enrolled in the study.The Portal Vein-phase enhancement scan was performed GSI spectrum protocol.The post-processing of the all images was used ASIR-V technology,the 6 reconstruction levels were respectively 0%,20%,40%,60%,80%,100%.By measuring CT and SD values of normal liver,spleen,kidney,erector spinae muscle and fat in 6 reconstruction levels of images,we calculated quantitatively the image noise(SD),signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR)of different groups.The overall image quality was scored by 1 to 5 points.The comparison of image quality between groups statistically used SPSS 22.0 software,including subjective and objective evaluation,P<0.05 indicated that the difference was statistically significant.Results 1)Objective evaluation The differences of CNR,SNR,SD among groups were statistically significant,respectively.As the reconstruction level increased,the image SNR and CNR values gradually increased,the noise SD gradually decreasedd,and the image quality improved;2)Subjective evaluation the images of ASIR-V 0%and 100%levels were worse,the highest score of image quality was 60%~80%level.There was no statistical difference in image quality between ASIR-V 40%and 100%,60%and 80%,and the differences between the remaining groups were statistically significant.Conclusion Based on subjective and objective evaluation,the ASIR-V reconstruction can optimize the low-dose CT image quality.When over-iteration,the waxy texture of the image is obvious,the tissue contrast is significantly reduced,and the details are unclear.And above all,ASIR-V about 60%~80%is the best.
作者
王宁
聂佩
杨光杰
姚建
赵霞
WANG Ning;NIE Pei;YANG Guangjie;YAO Jian;ZHAO Xia(Department of Medical Imaging, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan 250021, P.R.China;Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao 266003, P.R.China;Departmtent of Radiology, The Affiliated Hospital of Shandong University of TCM, Jinan 250000, P.R.China)
出处
《医学影像学杂志》
2022年第2期264-268,共5页
Journal of Medical Imaging
