Department of Radiology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea.
Department of Radiology, Gyeongsang National University Changwon Hospital, 555 Samjeongja-dong, Seongsan-gu, Changwon, Korea.
Abdom Radiol (NY). 2021 Oct;46(10):5037-5046. doi: 10.1007/s00261-021-03195-5. Epub 2021 Jul 2.
To evaluate effect of virtual monoenergetic reconstruction on contrast-enhanced abdominal CT obtained using a dual-layer detector CT (DLCT) in patients with arms-down positioning, in comparison with conventional 120-kVp image.
A total of 162 consecutive patients who underwent abdominal CT scans using a DLCT with arms-down positioning were retrospectively enrolled. 120-kVp image and virtual monoenergetic images (VMIs) at 40-100 keV were compared for arm-induced artifact reduction capability and image quality through objective and subjective assessments. Diagnostic performance was compared between VMI with the best quality and 120-kVp image.
VMIs at 60-100 keV showed significantly lower (p < 0.001) artifact index than 120-kVp image. Subjective severity of arm-induced streak artifacts was significantly (p < 0.001) lower in VMIs at 70-100 keV than in 120-kVp image. CNRs measured in artifact and reference areas were superior (p < 0.05) in 40-70 keV to those in 120 kVp. Overall image quality was superior (p < 0.05) in 60-90 keV to 120 kVp. 70-keV VMI was chosen as the best image by two independent readers. In ROC analysis of lesion detection in the liver, spleen, and kidneys, the AUC was significantly higher for 70-keV VMI (reader 1, 0.962; p = 0.011; reader 2, 0.981; p = 0.012) than that for 120-kVp image (reader 1, 0.891; reader 2, 0.922).
The70-keV VMI from DLCT could improve abdominal CT images by reducing streak artifacts and increasing image contrast in patients who could not elevated their arms. The 70-keV VMI showed better diagnostic performance than the conventional 120 kVp image.
评估在双臂下垂体位行双层探测器 CT（DLCT）腹部增强 CT 时，虚拟单能量重建对常规 120kVp 图像的影响。
回顾性纳入 162 例行双臂下垂体位腹部 CT 检查的患者，比较 120kVp 图像和 40-100keV 的虚拟单能量图像（VMI）在减少手臂伪影和图像质量方面的客观和主观评估。比较 VMI 与最佳质量图像和 120kVp 图像的诊断性能。
60-100keV 的 VMI 比 120kVp 图像的伪影指数显著降低（p<0.001）。70-100keV 的 VMI 比 120kVp 图像的手臂伪影严重程度显著降低（p<0.001）。在伪影和参考区域中，40-70keV 的 CNR 优于 120kVp（p<0.05）。60-90keV 的整体图像质量优于 120kVp（p<0.05）。两位独立读者均选择 70keV VMI 作为最佳图像。在肝脏、脾脏和肾脏病变检测的 ROC 分析中，70keV VMI 的 AUC 显著高于 120kVp 图像（读者 1，0.962；p=0.011；读者 2，0.981；p=0.012）。
DLCT 的 70keV VMI 可减少条纹伪影并提高不能抬高手臂患者的图像对比度，从而改善腹部 CT 图像。70keV VMI 的诊断性能优于常规 120kVp 图像。
