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Abstract：
BACKGROUND: To compare the potential of various bone evaluations by considering photon-counting CT (PCCT) and multiple energy-integrating-detector CT (EIDCT), including three dual-energy CT (DECT) scanners with standardized various parameters in both standard resolution (STD) and ultra-high-resolution (UHR) modes.
METHODS: Four cadaveric forearms were scanned using PCCT and five EIDCTs, by applying STD and UHR modes. Visibility of bone architecture, image quality, and a non-displaced fracture were subjectively scored against a reference EIDCT image by using a five-point scale. Image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were also compared. To assess metal artifacts, a forearm with radial plate fixation was scanned by with and without Tin filter (Sn+ and Sn-), and virtual monoenergetic image (VMI) at 120 keV was created. Regarding Sn+ and VMI, images were only obtained from the technically available scanners. Subjective scores and the areas of streak artifacts were compared.
RESULTS: PCCT demonstrated significantly lower noise (p < 0.001) and higher bone SNR and CNR (p < 0.001) than all EIDCTs in both resolution modes. However, there was no significant difference between PCCT and EIDCTs in almost all subjective scores, regardless of scan modes, except for image quality where a significant difference was observed, compared to several EIDCTs. Metal artifact analysis revealed PCCT had larger artifact in Sn- and Sn+ (p < 0.001), but fewer in VMIs than three DECTs (p < 0.001 or 0.001).
CONCLUSIONS: Under standardized conditions, while PCCT had almost no subjective superiority in visualizing bone structures and fracture line when compared to EIDCTs, it outperformed in quantitative analysis related to image quality, especially in lower noise and higher tissue contrast. When using PCCT to assess cases with metal implants, it may be recommended to use VMIs to minimize the possible tendency for artifact to be pronounced.
METHODS: Four cadaveric forearms were scanned using PCCT and five EIDCTs, by applying STD and UHR modes. Visibility of bone architecture, image quality, and a non-displaced fracture were subjectively scored against a reference EIDCT image by using a five-point scale. Image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were also compared. To assess metal artifacts, a forearm with radial plate fixation was scanned by with and without Tin filter (Sn+ and Sn-), and virtual monoenergetic image (VMI) at 120 keV was created. Regarding Sn+ and VMI, images were only obtained from the technically available scanners. Subjective scores and the areas of streak artifacts were compared.
RESULTS: PCCT demonstrated significantly lower noise (p < 0.001) and higher bone SNR and CNR (p < 0.001) than all EIDCTs in both resolution modes. However, there was no significant difference between PCCT and EIDCTs in almost all subjective scores, regardless of scan modes, except for image quality where a significant difference was observed, compared to several EIDCTs. Metal artifact analysis revealed PCCT had larger artifact in Sn- and Sn+ (p < 0.001), but fewer in VMIs than three DECTs (p < 0.001 or 0.001).
CONCLUSIONS: Under standardized conditions, while PCCT had almost no subjective superiority in visualizing bone structures and fracture line when compared to EIDCTs, it outperformed in quantitative analysis related to image quality, especially in lower noise and higher tissue contrast. When using PCCT to assess cases with metal implants, it may be recommended to use VMIs to minimize the possible tendency for artifact to be pronounced.
摘要：
背景：通过考虑光子计数CT（PCCT）和多能量积分探测器CT（EIDCT）来比较各种骨骼评估的潜力，包括三个双能量CT（DECT）扫描仪，在标准分辨率（STD）和超高分辨率（UHR）模式下具有标准化的各种参数。
方法：使用PCCT和五个EIDCT扫描四个尸体前臂，通过应用STD和UHR模式。骨骼结构的能见度，图像质量，使用五点量表对参考EIDCT图像对未移位的骨折进行主观评分。图像噪声,还比较了信噪比（SNR）和对比度噪声比（CNR）。为了评估金属伪影，使用和不使用Tin过滤器（Sn和Sn-）扫描带有radial板固定的前臂，并创建了120keV的虚拟单能量图像(VMI)。关于Sn+和VMI，图像只能从技术上可用的扫描仪获得。比较了主观得分和条纹伪影的面积。
结果：在两种分辨率模式下，PCCT均显示出比所有EIDCT均显着更低的噪声（p<0.001）和更高的骨骼SNR和CNR（p<0.001）。然而,PCCT和EIDCT在几乎所有主观评分上都没有显着差异，无论何种扫描模式，除了观察到显著差异的图像质量，与几个EIDCT相比。金属伪影分析显示PCCT在Sn-和Sn+中有较大的伪影（p<0.001），但VMI低于3个DECT(p<0.001或0.001)。
结论：在标准化条件下，虽然与EIDCT相比，PCCT在可视化骨结构和骨折线方面几乎没有主观优势，它在与图像质量相关的定量分析中表现出色，特别是在较低的噪声和较高的组织对比度。当使用PCCT评估带有金属植入物的病例时，可以推荐使用VMI来最小化伪像被显著的可能趋势。
方法：使用PCCT和五个EIDCT扫描四个尸体前臂，通过应用STD和UHR模式。骨骼结构的能见度，图像质量，使用五点量表对参考EIDCT图像对未移位的骨折进行主观评分。图像噪声,还比较了信噪比（SNR）和对比度噪声比（CNR）。为了评估金属伪影，使用和不使用Tin过滤器（Sn和Sn-）扫描带有radial板固定的前臂，并创建了120keV的虚拟单能量图像(VMI)。关于Sn+和VMI，图像只能从技术上可用的扫描仪获得。比较了主观得分和条纹伪影的面积。
结果：在两种分辨率模式下，PCCT均显示出比所有EIDCT均显着更低的噪声（p<0.001）和更高的骨骼SNR和CNR（p<0.001）。然而,PCCT和EIDCT在几乎所有主观评分上都没有显着差异，无论何种扫描模式，除了观察到显著差异的图像质量，与几个EIDCT相比。金属伪影分析显示PCCT在Sn-和Sn+中有较大的伪影（p<0.001），但VMI低于3个DECT(p<0.001或0.001)。
结论：在标准化条件下，虽然与EIDCT相比，PCCT在可视化骨结构和骨折线方面几乎没有主观优势，它在与图像质量相关的定量分析中表现出色，特别是在较低的噪声和较高的组织对比度。当使用PCCT评估带有金属植入物的病例时，可以推荐使用VMI来最小化伪像被显著的可能趋势。
