Abstract：
To evaluate the image quality and diagnostic performance for pancreatic lesion between true non-contrast (TNC) and virtual non-contrast (VNC) images obtained from the dual-energy computed tomography (DECT).
One hundred six patients with pancreatic mass underwent contrast-enhanced DECT examinations were retrospectively included in this study. VNC images of the abdomen were generated from late arterial (aVNC) and portal (pVNC) phases. For quantitative analysis, the attenuation differences and reproducibility of abdominal organs were compared between TNC and aVNC/pVNC measurements. Qualitatively image quality was assessed by two radiologists using a five-point scale, and they independently compared the detection accuracy of pancreatic lesions between TNC and aVNC/pVNC images. The volume CT dose index (CTDIvol) and size-specific dose estimates (SSDE) were recorded to evaluate the potential dose reduction when using VNC reconstruction to replace the unenhanced phase.
A total of 78.38% (765/976) of the attenuation measurement pairs were reproducible between TNC and aVNC images, and 71.0% (693/976) between TNC and pVNC images. In triphasic examinations, a total of 108 pancreatic lesions were found in 106 patients, and no significant difference in detection accuracy was found between TNC and VNC images (p = 0.587-0.957). Qualitatively, image quality was rated diagnostic (score ≥ 3) in all the VNC images. Calculated CTDIvol and SSDE reduction of about 34% could be achieved by omitting the non-contrast phase.
VNC images of DECT provide diagnostic image quality and accurate pancreatic lesions detection, which are a promising alternative to unenhanced phase with a substantial reduction of radiation exposure in clinical routine.
One hundred six patients with pancreatic mass underwent contrast-enhanced DECT examinations were retrospectively included in this study. VNC images of the abdomen were generated from late arterial (aVNC) and portal (pVNC) phases. For quantitative analysis, the attenuation differences and reproducibility of abdominal organs were compared between TNC and aVNC/pVNC measurements. Qualitatively image quality was assessed by two radiologists using a five-point scale, and they independently compared the detection accuracy of pancreatic lesions between TNC and aVNC/pVNC images. The volume CT dose index (CTDIvol) and size-specific dose estimates (SSDE) were recorded to evaluate the potential dose reduction when using VNC reconstruction to replace the unenhanced phase.
A total of 78.38% (765/976) of the attenuation measurement pairs were reproducible between TNC and aVNC images, and 71.0% (693/976) between TNC and pVNC images. In triphasic examinations, a total of 108 pancreatic lesions were found in 106 patients, and no significant difference in detection accuracy was found between TNC and VNC images (p = 0.587-0.957). Qualitatively, image quality was rated diagnostic (score ≥ 3) in all the VNC images. Calculated CTDIvol and SSDE reduction of about 34% could be achieved by omitting the non-contrast phase.
VNC images of DECT provide diagnostic image quality and accurate pancreatic lesions detection, which are a promising alternative to unenhanced phase with a substantial reduction of radiation exposure in clinical routine.
摘要：
目的：评估从双能计算机断层扫描（DECT）获得的真实非对比（TNC）和虚拟非对比（VNC）图像之间的图像质量和胰腺病变的诊断性能。
方法：本研究回顾性纳入了106例接受对比增强DECT检查的胰腺肿块患者。从晚期动脉（aVNC）和门静脉（pVNC）阶段生成腹部的VNC图像。为了进行定量分析，比较了TNC和aVNC/pVNC测量结果的腹部器官衰减差异和可重复性.定性图像质量由两名放射科医生使用五点量表进行评估，他们独立比较了TNC和aVNC/pVNC图像对胰腺病变的检测准确性。记录体积CT剂量指数（CTDIvol）和特定尺寸剂量估计值（SSDE），以评估使用VNC重建代替未增强阶段时的潜在剂量减少。
结果：在TNC和aVNC图像之间，总共78.38％（765/976）的衰减测量对是可重复的，TNC和pVNC图像之间的71.0%(693/976)。在三相检查中，106例患者共发现108例胰腺病变,TNC和VNC图像之间的检测准确性没有发现显着差异（p=0.587-0.957）。定性,所有VNC图像的图像质量均为诊断性(评分≥3分).通过省略非对比阶段,可以实现约34%的计算的CTDIvol和SSDE减少。
结论：DECT的VNC图像提供诊断图像质量和准确的胰腺病变检测，这是一个有希望的替代未增强阶段，并在临床常规中大幅减少辐射暴露。
方法：本研究回顾性纳入了106例接受对比增强DECT检查的胰腺肿块患者。从晚期动脉（aVNC）和门静脉（pVNC）阶段生成腹部的VNC图像。为了进行定量分析，比较了TNC和aVNC/pVNC测量结果的腹部器官衰减差异和可重复性.定性图像质量由两名放射科医生使用五点量表进行评估，他们独立比较了TNC和aVNC/pVNC图像对胰腺病变的检测准确性。记录体积CT剂量指数（CTDIvol）和特定尺寸剂量估计值（SSDE），以评估使用VNC重建代替未增强阶段时的潜在剂量减少。
结果：在TNC和aVNC图像之间，总共78.38％（765/976）的衰减测量对是可重复的，TNC和pVNC图像之间的71.0%(693/976)。在三相检查中，106例患者共发现108例胰腺病变,TNC和VNC图像之间的检测准确性没有发现显着差异（p=0.587-0.957）。定性,所有VNC图像的图像质量均为诊断性(评分≥3分).通过省略非对比阶段,可以实现约34%的计算的CTDIvol和SSDE减少。
结论：DECT的VNC图像提供诊断图像质量和准确的胰腺病变检测，这是一个有希望的替代未增强阶段，并在临床常规中大幅减少辐射暴露。
