Department of Radiology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, PR China.
GE Healthcare, Computed Tomography Research Center, Beijing, 100176, PR China.
Eur J Radiol. 2020 Jul;128:109061. doi: 10.1016/j.ejrad.2020.109061. Epub 2020 May 12.
Investigate the clinical value of improving diagnostic accuracy for arteries of lower extremities with low energy images in dual-energy spectral CT (DEsCT) imaging.
110 (mean age, 67 ± 10 years) and 72 (mean age, 65 ± 13 years) patients underwent CT angiography (CTA) in the lower extremities using dual-energy and conventional (100kVp) imaging mode, retrospectively. The 50 keV monochromatic images were reconstructed in the DEsCT group for analysis. The quantitative and qualitative image quality of the two groups were compared using various statistical analysis methods and the diagnostic accuracy for the degree of vessel stenosis was compared using DSA as the gold standard. Consistency test was used for intra-group evaluation. A P < 0.05 was considered statistically significant.
The use of 50 keV images in DEsCT significantly increased the enhancement in arteries of LKS (544.91 ± 106.37HU vs. 339.65 ± 83.74HU, P < 0.001) and provided higher SNR (19.92±9.39 vs. 17.39±4.99, P = 0.04) and CNR (45.60±16.61 vs. 38.70±18.17, P < 0.01) compared with conventional 100kVp images. Mann-Whitney test showed that the subjective image quality of the arteries of lower knee segment (LKS) in the DEsCT group was higher than in the conventional group (P = 0.01). The diagnostic efficiency of DEsCT group was better than that of conventional group, mainly in arteries of LKS (95.91 % vs. 87.85 %, for 50 % stenosis, P<0.001; 94.32 % vs. 89.58 % for occlusion, P = 0.02).
The use of 50 keV DEsCT images enhances the contrast in the lower extremity arteries and improves the diagnostic accuracy for the arteries of LKS, compared with the conventional CTA protocols.
探讨双能光谱 CT（DEsCT）成像中低能图像提高下肢动脉诊断准确性的临床价值。
回顾性分析 110 例（平均年龄 67±10 岁）和 72 例（平均年龄 65±13 岁）患者行下肢 CT 血管造影（CTA）检查，采用双能和常规（100kVp）两种成像模式。DEsCT 组对 50keV 单能图像进行重建并进行分析。使用各种统计分析方法比较两组的定量和定性图像质量，并以 DSA 为金标准比较两种方法对血管狭窄程度的诊断准确性。采用一致性检验对内组进行评价。P<0.05 为差异有统计学意义。
DEsCT 组使用 50keV 图像可显著提高 LKS 动脉强化程度（544.91±106.37HU 比 339.65±83.74HU，P<0.001），并提供更高的信噪比（19.92±9.39 比 17.39±4.99，P=0.04）和对比噪声比（45.60±16.61 比 38.70±18.17，P<0.01），与常规 100kVp 图像相比。Mann-Whitney 检验显示，DEsCT 组膝关节下段动脉（LKS）的主观图像质量高于常规组（P=0.01）。DEsCT 组的诊断效率优于常规组，主要在 LKS 动脉（50%狭窄时 95.91%比 87.85%，P<0.001；闭塞时 94.32%比 89.58%，P=0.02）。
与常规 CTA 方案相比，使用 50keV DEsCT 图像可增强下肢动脉对比度，提高 LKS 动脉的诊断准确性。
