Lee Ji Won, Lee Geewon, Lee Nam Kyung, Moon Jin Il, Ju Yun Hye, Suh Young Ju, Jeong Yeon Joo
From the *Department of Radiology, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Busan; †Department of Biomedical Engineering, Yonsei University, Wonju; and ‡Department of Biomedical Sciences, School of Medicine, Inha University, Incheon, Republic of Korea.
J Comput Assist Tomogr. 2016 Sep-Oct;40(5):777-83. doi: 10.1097/RCT.0000000000000443.
The aim of the study was to assess the effectiveness of the adaptive statistical iterative reconstruction (ASIR) for dual-energy computed tomography pulmonary angiography (DE-CTPA) with a reduced iodine load.
One hundred forty patients referred for chest CT were randomly divided into a DE-CTPA group with a reduced iodine load or a standard CTPA group. Quantitative and qualitative image qualities of virtual monochromatic spectral (VMS) images with filtered back projection (VMS-FBP) and those with 50% ASIR (VMS-ASIR) in the DE-CTPA group were compared. Image qualities of VMS-ASIR images in the DE-CTPA group and ASIR images in the standard CTPA group were also compared.
All quantitative and qualitative indices, except attenuation value of pulmonary artery in the VMS-ASIR subgroup, were superior to those in the VMS-FBP subgroup (all P < 0.001). Noise and signal-to-noise ratio of VMS-ASIR images were superior to those of ASIR images in the standard CTPA group (P < 0.001 and P = 0.007, respectively). Regarding qualitative indices, noise was significantly lower in VMS-ASIR images of the DE-CTPA group than in ASIR images of the standard CTPA group (P = 0.001).
The ASIR technique tends to improve the image quality of VMS imaging. Dual-energy computed tomography pulmonary angiography with ASIR can reduce contrast medium volume and produce images of comparable quality with those of standard CTPA.
本研究旨在评估自适应统计迭代重建（ASIR）技术在减少碘负荷的双能量计算机断层扫描肺血管造影（DE-CTPA）中的有效性。
将140例因胸部CT检查而就诊的患者随机分为低碘负荷DE-CTPA组或标准CTPA组。比较DE-CTPA组中采用滤波反投影（VMS-FBP）的虚拟单色光谱（VMS）图像以及采用50%ASIR的VMS图像（VMS-ASIR）的定量和定性图像质量。还比较了DE-CTPA组中VMS-ASIR图像与标准CTPA组中ASIR图像的质量。
除VMS-ASIR亚组中肺动脉的衰减值外，所有定量和定性指标均优于VMS-FBP亚组（所有P<0.001）。VMS-ASIR图像的噪声和信噪比优于标准CTPA组中的ASIR图像（分别为P<0.001和P=0.007）。在定性指标方面，DE-CTPA组VMS-ASIR图像的噪声明显低于标准CTPA组的ASIR图像（P=0.001）。
ASIR技术倾向于改善VMS成像的图像质量。采用ASIR的双能量计算机断层扫描肺血管造影可以减少对比剂用量，并产生与标准CTPA质量相当的图像。
