Model-Based Iterative Reconstruction Technique for Ultralow-Dose Computed Tomography of the Lung A Pilot Study
Model-Based Iterative Reconstruction Technique for Ultralow-Dose Computed Tomography of the Lung A Pilot Study
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DOI：
10.1097/rli.0b013e3182562a89
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发表时间：
2012-08-01
影响因子：
6.7
通讯作者：
Kuribayashi, Sachio
中科院分区：
文献类型：
--
作者：
Yamada, Yoshitake;Jinzaki, Masahiro;Kuribayashi, Sachio
目的：本研究的目的是评估的有效性，基于模型的迭代重建（MBIR）在提高图像质量和诊断性能的超低剂量计算机断层扫描（ULDCT）的lung.Materials和Methods：机构审查委员会批准了这项研究，所有患者提供书面知情同意书。52例患者同时接受了肺的低剂量计算机断层扫描（LDCT）（筛选剂量，50 mAs）和ULDCT（4 mAs）。LDCT图像采用滤波反投影重建（LDCT-FBP图像），ULDCT图像采用MBIR重建（ULDCT-MBIR图像）和FBP重建（ULDCT-FBP图像）。在所有156个图像系列中，测量胸主动脉中的客观图像噪声，并且由2名设盲的放射科医师独立评估主观图像质量。另2名设盲放射科医师独立评价ULDCT-MBIR和ULDCT-FBP图像是否存在非钙化和钙化肺结节; LDCT-FBP图像作为参考。结果：与LDCT-FBP和ULDCT-FBP相比，ULDCT-MBIR的客观噪声显著降低（P均<0.001），而与LDCT-FBP相比，ULDCT-MBIR的客观噪声显著降低（P均< 0.001）。ULDCT-MBIR图像的主观噪声与LDCT-FBP图像相当，但低于ULDCT-FBP图像（P < 0.001）。ULDCT-MBIR图像上的伪影数量多于LDCT-FBP图像上的伪影（P = 0.007），但少于ULDCT-FBP图像上的伪影（P < 0.001）。与LDCT-FBP图像相比，ULDCT-MBIR和ULDCT-FBP图像显示图像清晰度降低（均P < 0.001）。所有ULDCT-MBIR图像均显示斑点状像素化外观;然而，对于非钙化肺结节的检测，ULDCT-MBIR的性能显著上级ULDCT-FBP（P = 0.002）。显著大小的非钙化结节（>= 4 mm）和小的非钙化结节（
Objectives: The aim of this study was to assess the effectiveness of a model-based iterative reconstruction (MBIR) in improving image quality and diagnostic performance of ultralow-dose computed tomography (ULDCT) of the lung.Materials and Methods: The institutional review board approved this study, and all patients provided written informed consent. Fifty-two patients underwent low-dose computed tomography (LDCT) (screening-dose, 50 mAs) and ULDCT (4 mAs) of the lung simultaneously. The LDCT images were reconstructed with filtered back projection (LDCT-FBP images) and ULDCT images were reconstructed with both MBIR (ULDCT-MBIR images) and FBP (ULDCT-FBP images). On all the 156 image series, objective image noise was measured in the thoracic aorta, and 2 blinded radiologists independently assessed subjective image quality. Another 2 blinded radiologists independently evaluated the ULDCT-MBIR and ULDCT-FBP images for the presence of noncalcified and calcified pulmonary nodules; LDCT-FBP images served as the reference. Paired t test, Wilcoxon signed rank sum test, and free-response receiver-operating characteristic analysis were used for statistical analysis of the data.Results: Compared with LDCT-FBP and ULDCT-FBP, ULDCT-MBIR had significantly reduced objective noise (both P < 0.001). Subjective noise on the ULDCT-MBIR images was comparable with that on the LDCT-FBP images but lower than that on the ULDCT-FBP images (P < 0.001). Artifacts on ULDCT-MBIR images were more numerous than those on the LDCT-FBP images (P = 0.007) but fewer than those on the ULDCT-FBP images (P < 0.001). Compared with the LDCT-FBP images, ULDCT-MBIR and ULDCT-FBP images showed reduced image sharpness (both P < 0.001). All the ULDCT-MBIR images showed a blotchy pixelated appearance; however, the performance of ULDCT-MBIR was significantly superior to that of ULDCT-FBP for the detection of noncalcified pulmonary nodules (P = 0.002). The average true-positive fractions for significantly sized noncalcified nodules (>= 4 mm) and small noncalcified nodules (