Wang Weibing, Huang Jinbai, Wang Ai, Li Yun, Peng Jie, Hu Xinjie, Liu Yingjun, Zhang Haiyan, Li Xiaohu
Department of Radiology, The First Affiliated Hospital of Anhui Medical University, Anhui, Hefei, China.
J Comput Assist Tomogr. 2018 Nov/Dec;42(6):954-958. doi: 10.1097/RCT.0000000000000785.
The aim of the study was to investigate whether spectral computed tomography (CT) plus adaptive statistical iterative reconstruction (ASIR) could improve imaging quality of computed tomography portal venography (CTPV).
Sixty-four patients underwent CTPV, with CT number of portal vein (PV) less than 150 HU in portal phase, were divided into 2 groups A (n = 31), using standard 120-kVp protocol. group B (n = 33), using spectral CT protocol. Standard 120-kVp images were reconstructed with 40% ASIR, and monochromatic images at 60 keV were reconstructed with the following 4 ASIR percentages: 0%, 20%, 40%, and 60%. The CT number, image noise, and contrast-to-noise ratio in main PV were measured. The maximum intensity projection and volume-rendering images were used for subjective evaluation. These 2 kinds of results were statistically analyzed.
The contrast-to-noise ratio and subjective scoring of PV increased gradually from 120-kVp images to 60% weight ASIR (3.44 ± 0.95, 4.58 ± 1. 59, 5.26 ± 1.85, 6.18 ± 2.18, and 7.39 ± 2.65 and 4.35 ± 1.17, 6.21 ± 1.29, 6.48 ± 1.35, 6.85 ± 1.28, and 7.00 ± 1.19). There were statistically different for the 5 groups (P < 0.001). The CT number of the PV in the 60-kiloelectron volt spectral images had higher than the 120-kVp images (P < 0.001). The noise of 120 kVp was significantly higher than those of 60% ASIR and significantly lower than those of 0% ASIR (both P < 0.001), and there were no significant differences between 120-kVp, 20% ASIR, and 40% ASIR (P = 0.107 and 1.000, respectively). The diagnostic acceptability was highest at 40% ASIR.
Forty-percent ASIR addition to the 60-kiloelectron volt monochromatic image could improve image quality of CTPV comparing with conventional 120-kVp images.
本研究旨在探讨光谱计算机断层扫描（CT）联合自适应统计迭代重建（ASIR）是否能提高计算机断层扫描门静脉造影（CTPV）的成像质量。
64例接受CTPV检查且门静脉期门静脉（PV）CT值小于150 HU的患者被分为两组。A组（n = 31）采用标准120 kVp协议，B组（n = 33）采用光谱CT协议。标准120 kVp图像采用40% ASIR重建，60 keV单色图像采用以下4种ASIR百分比重建：0%、20%、40%和60%。测量主PV的CT值、图像噪声和对比噪声比。采用最大密度投影和容积再现图像进行主观评价。对这两种结果进行统计学分析。
PV的对比噪声比和主观评分从120 kVp图像到60%权重ASIR逐渐增加（3.44±0.95、4.58±1.59、5.26±1.85、6.18±2.18和7.39±2.65以及4.35±1.17、6.21±1.29、6.48±1.35、6.85±1.28和7.00±1.19）。5组间差异有统计学意义（P < 0.001）。60 keV光谱图像中PV的CT值高于标准120 kVp图像（P < 0.001）。120 kVp的噪声显著高于60% ASIR的噪声，显著低于0% ASIR的噪声（均P < 0.001），120 kVp、20% ASIR和40% ASIR之间无显著差异（P分别为0.107和1.00）。40% ASIR时诊断可接受性最高。
与传统120 kVp图像相比，在60 keV单色图像上增加40% ASIR可提高CTPV的图像质量。
