Woisetschläger Mischa, Henriksson Lilian, Bartholomae Wolf, Gasslander Thomas, Björnsson Bergthor, Sandström Per
Department of Radiology in Linköping, and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.
Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
Eur J Radiol Open. 2020 Jul 3;7:100243. doi: 10.1016/j.ejro.2020.100243. eCollection 2020.
To investigate differences between reconstruction algorithms in quantitative perfusion values and time-attenuation curves in computed tomography perfusion (CTP) examinations of the upper abdomen.
Twenty-six CTP examinations were reconstructed with filtered back projection and an iterative reconstruction algorithm, advanced modeled iterative reconstruction (ADMIRE), with different levels of noise-reduction strength. Using the maximum-slope model, quantitative measurements were obtained: blood flow (mL/min/100 mL), blood volume (mL/100 mL), time to peak (s), arterial liver perfusion (mL/100 mL/min), portal venous liver perfusion (mL/100 mL/min), hepatic perfusion index (%), temporal maximum intensity projection (Hounsfield units (HU)) and temporal average HU. Time-attenuation curves for seven sites (left liver lobe, right liver lobe, hepatocellular carcinoma, spleen, gastric wall, pancreas, portal vein) were obtained. Mixed-model analysis was used for statistical evaluation. Image noise and the signal:noise ratio (SNR) were compared between four reconstructions, and statistical analysis of these reconstructions was made with a related-samples Friedman's two-way analysis of variance by ranks test.
There were no significant differences for quantitative measurements between the four reconstructions for all tissues. There were no significant differences between the AUC values of the time-attenuation curves between the four reconstructions for all tissues, including three automatic measurements (portal vein, aorta, spleen). There was a significant difference in image noise and SNR between the four reconstructions.
ADMIRE did not affect the quantitative measurements or time-attenuation curves of tissues in the upper abdomen. The image noise was lower, and the SNR higher, for iterative reconstructions with higher noise-reduction strengths.
探讨在上腹部计算机断层扫描灌注（CTP）检查中，重建算法在定量灌注值和时间-衰减曲线方面的差异。
对26例CTP检查采用滤波反投影和迭代重建算法（先进的模型迭代重建，ADMIRE）进行重建，且具有不同水平的降噪强度。使用最大斜率模型进行定量测量：血流量（毫升/分钟/100毫升）、血容量（毫升/100毫升）、达峰时间（秒）、肝动脉灌注（毫升/100毫升/分钟）、肝门静脉灌注（毫升/100毫升/分钟）、肝灌注指数（%）、时间最大密度投影（亨氏单位（HU））和时间平均HU。获取七个部位（肝左叶、肝右叶、肝细胞癌、脾脏、胃壁、胰腺、门静脉）的时间-衰减曲线。采用混合模型分析进行统计学评估。比较四种重建图像的噪声和信噪比（SNR），并使用相关样本弗里德曼双向秩次方差分析对这些重建进行统计学分析。
所有组织的四种重建在定量测量方面无显著差异。所有组织的四种重建在时间-衰减曲线的AUC值之间无显著差异，包括三项自动测量（门静脉、主动脉、脾脏）。四种重建在图像噪声和SNR方面存在显著差异。
ADMIRE不影响上腹部组织的定量测量或时间-衰减曲线。对于具有较高降噪强度的迭代重建，图像噪声较低，SNR较高。
