Sun Jihang, Yu Tong, Liu Jinrong, Duan Xiaomin, Hu Di, Liu Yong, Peng Yun
Imaging Center, Beijing Children's Hospital, Capital Medical University, No.56, Nanlishi Road, Xicheng District, Beijing, 100045, People's Republic of China.
Department of respiratory, Beijing Children's Hospital, Capital Medical University, Beijing, 100045, People's Republic of China.
BMC Med Imaging. 2017 Mar 16;17(1):24. doi: 10.1186/s12880-017-0177-9.
Model-based iterative reconstruction (MBIR) is a promising reconstruction method which could improve CT image quality with low radiation dose. The purpose of this study was to demonstrate the advantage of using MBIR for noise reduction and image quality improvement in low dose chest CT for children with necrotizing pneumonia, over the adaptive statistical iterative reconstruction (ASIR) and conventional filtered back-projection (FBP) technique.
Twenty-six children with necrotizing pneumonia (aged 2 months to 11 years) who underwent standard of care low dose CT scans were included. Thinner-slice (0.625 mm) images were retrospectively reconstructed using MBIR, ASIR and conventional FBP techniques. Image noise and signal-to-noise ratio (SNR) for these thin-slice images were measured and statistically analyzed using ANOVA. Two radiologists independently analyzed the image quality for detecting necrotic lesions, and results were compared using a Friedman's test.
Radiation dose for the overall patient population was 0.59 mSv. There was a significant improvement in the high-density and low-contrast resolution of the MBIR reconstruction resulting in more detection and better identification of necrotic lesions (38 lesions in 0.625 mm MBIR images vs. 29 lesions in 0.625 mm FBP images). The subjective display scores (mean ± standard deviation) for the detection of necrotic lesions were 5.0 ± 0.0, 2.8 ± 0.4 and 2.5 ± 0.5 with MBIR, ASIR and FBP reconstruction, respectively, and the respective objective image noise was 13.9 ± 4.0HU, 24.9 ± 6.6HU and 33.8 ± 8.7HU. The image noise decreased by 58.9 and 26.3% in MBIR images as compared to FBP and ASIR images. Additionally, the SNR of MBIR images was significantly higher than FBP images and ASIR images.
The quality of chest CT images obtained by MBIR in children with necrotizing pneumonia was significantly improved by the MBIR technique as compared to the ASIR and FBP reconstruction, to provide a more confident and accurate diagnosis for necrotizing pneumonia.
基于模型的迭代重建（MBIR）是一种很有前景的重建方法，它可以在低辐射剂量下提高CT图像质量。本研究的目的是证明在患有坏死性肺炎的儿童低剂量胸部CT中，与自适应统计迭代重建（ASIR）和传统滤波反投影（FBP）技术相比，使用MBIR进行降噪和改善图像质量的优势。
纳入26例接受标准护理低剂量CT扫描的坏死性肺炎儿童（年龄2个月至11岁）。使用MBIR、ASIR和传统FBP技术对薄层（0.625mm）图像进行回顾性重建。测量这些薄层图像的图像噪声和信噪比（SNR），并使用方差分析进行统计分析。两名放射科医生独立分析检测坏死性病变的图像质量，并使用Friedman检验比较结果。
总体患者群体的辐射剂量为0.59mSv。MBIR重建的高密度和低对比度分辨率有显著改善，从而能检测到更多坏死性病变并更好地识别（0.625mm MBIR图像中有38个病变，而0.625mm FBP图像中有29个病变）。MBIR、ASIR和FBP重建检测坏死性病变的主观显示评分（平均值±标准差）分别为5.0±0.0、2.8±0.4和2.5±0.5，各自的客观图像噪声分别为13.9±4.0HU、24.9±6.6HU和33.8±8.7HU。与FBP和ASIR图像相比，MBIR图像的噪声分别降低了58.9%和26.3%。此外，MBIR图像的SNR显著高于FBP图像和ASIR图像。
与ASIR和FBP重建相比，MBIR技术显著提高了坏死性肺炎儿童胸部CT图像的质量，为坏死性肺炎提供了更可靠、准确的诊断。
