摘要
目的探讨能谱CT最佳虚拟单能量成像(VMS)联合自适应迭代重建(ASIR)技术在双期胸部增强CT扫描中的应用价值。资料与方法采用前瞻性研究方法收集60例行能谱CT双期胸部增强扫描的患者。其中研究组30例行80~140 k Vp能谱CT扫描,对照组30例采用120 k Vp常规CT扫描,分别使用滤波反投影(FBP)技术和ASIR对图像进行重建,得到VMS-FBP(A组)、VMS-ASIR(B组)、120 k Vp-FBP(C组)、120 k Vp-ASIR(D组)重建图像。比较4组重建后图像在双期不同层面降主动脉的信噪比(SNR)和对比噪声比(CNR);对4组图像质量进行评分;并比较研究组和对照组的辐射剂量。结果研究组较对照组有效辐射剂量下降了36.01%,差异有统计学意义(t=172.00,P<0.001)。A^D组图像的CT值、CNR、SNR和图像质量主观评分差异均有统计学意义(P<0.05)。结论与120 k Vp常规CT扫描模式相比,VMS联合ASIR可以获得较好的图像质量,降低辐射剂量。
Purpose To explore the diagnostic value of virtual monochromatic spectrum（VMS） combined with adaptive statistical iterative reconstruction（ASIR） technique in dual-phase contrast-enhanced chest CT. Material and Methods Sixty patients were prospectively scanned using spectral dual-phase contrast-enhanced chest CT, of which thirty patients were in study group with 80-140 k Vp spectral CT, and thirty patients in control group with 120 k Vp routine CT scanning. The images were reconstructed using filtered back projection（FBP）（group A） and ASIR（group B）, respectively, with a total of 4 groups： VMS-FBP（group A）, VMS-ASIR（group B）, 120 k Vp-FBP（group C）, and 120 k Vp-ASIR（group D）.The contrast noise ratio（CNR） and signal noise ratio（SNR） relative to muscle for descending aorta at different levels during arterial and venous phases were evaluated for each group. The image quality was scored and radiation dose was compared between study and control groups. Results The effective radiation dose in study group was 36.01% lower than that in control group and statistically significant（t=172.00, P0.001）. The differences in CT attenuation, CNR, SNR and the subjective image quality score among four groups showed statistically different（P0.05）. Conclusion Compared to conventional 120 k Vp imaging, VMS-ASIR decreases radiation dose and improves image quality.
出处
《中国医学影像学杂志》
CSCD
北大核心
2016年第10期746-749,754,共5页
Chinese Journal of Medical Imaging
关键词
体层摄影术
X线计算机
迭代重建算法
胸部
肺疾病
图像增强
迭代重建
图像处理
计算机辅助
质量控制
辐射剂量
Tomography
X-ray computed
Iterative reconstruction
Thorax
Lung diseases
Image enhancement
Iterative reconstruction algorithm
Image processing
computer-assisted
Quality control
Radiation dosage
