双层光谱探测器CT虚拟单能成像降低婴幼儿复杂先心病对比剂剂量的可行性
前瞻性纳入80例复杂先天性心脏病婴幼儿，随机分为标准剂量组（1.5-2 ml/kg，n=36）和低剂量组（1 ml/kg，n=44），低剂量组重建40-85 keV虚拟单能图像。低剂量组对比剂用量减少24%，40 keV虚拟单能图像客观质量优于标准剂量组常规图像，40-50 keV主观评分更高，诊断准确率97.7%优于标准剂量组的93.4%。
要点
- 低剂量组对比剂用量较标准剂量组减少24%，40 keV虚拟单能图像可补偿图像质量。
- 40 keV虚拟单能图像在肺动脉和升主动脉的CT值、SNR、CNR最高，优于标准剂量组常规图像。
- 40-50 keV虚拟单能图像主观评分及诊断准确率（97.7%）均优于标准剂量组常规图像（93.4%）。
关键影像表现/征象
- 低剂量组对比剂用量8.0（5.0; 11.0）ml，标准剂量组10.5（8.0; 21.0）ml，低剂量组减少24%（P<0.05）。
- 40 keV虚拟单能图像在肺动脉和升主动脉的CT值、SNR、CNR最高，显著优于标准剂量组常规图像（P<0.05）。
- 低剂量组40-50 keV虚拟单能图像主观评分显著高于标准剂量组常规图像（P<0.05）。
诊断标准与关键数值
- 低剂量组40-50 keV虚拟单能图像诊断复杂先心病的准确率为97.7%，显著高于标准剂量组常规图像的93.4%（P<0.05）。
- 两组间诊断敏感度和特异度无显著差异。
临床应用与阅片要点
- 对婴幼儿复杂先心病术前CT，可采用1 ml/kg对比剂并结合40 keV虚拟单能图像重建，以降低对比剂负担。
- 40-50 keV虚拟单能图像可提供优于常规图像的客观和主观图像质量，推荐用于肺动脉和升主动脉评估。
- 低剂量方案不影响诊断敏感度和特异度，但需注意keV优化对图像噪声和对比度的平衡。
以上解读依据论文摘要（全文未开放获取或许可不允许翻译转载）。
英文原文（摘要）· 点击展开
BACKGROUND: Virtual monoenergetic imaging (VMI) with dual-layer spectral detector computed tomography (CT) enables keV optimization, offering the potential for contrast dose reduction, particularly beneficial in pediatric imaging. However, its clinical utility in infants and children with complex congenital heart disease (CHD) remains underexplored.
OBJECTIVE: To investigate the feasibility of reducing the contrast dose and the optimal keV of virtual monoenergetic images (VMIs) on dual-layer spectral detector CT in infants and children with complex CHD.
MATERIALS AND METHODS: Prospectively enrolled 80 infants and children with complex CHD and underwent preoperative dual-layer spectral detector CT. Patients were randomly divided into two groups: group A (n=36, standard dose, 1.5-2 ml/kg) and group B (n=44, low dose, 1 ml/kg). Conventional image and VMIs in range of 40-85 keV were reconstructed in group B while only conventional image was reconstructed in group A. Image quality was evaluated using qualitative scores and objective metrics including CT-value, standard deviation (SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) for the pulmonary artery and ascending aorta.
RESULTS: Group B received 24% less contrast than group A [8.0 (5.0; 11.0) ml vs. 10.5 (8.0; 21.0) ml, P<0.05]. VMI 40 keV in group B yielded the highest CT-value, SNR, CNR of pulmonary artery, and ascending aorta among different VMIs, and significantly outperformed conventional image in group A (P<0.05). Subjective evaluation score on VMI 40-50 keV of group B was significantly higher than conventional image of group A (P<0.05). Diagnostic accuracy for CHD at 40-50 keV in group B was 97.7%, significantly higher than group A (93.4%, P<0.05), while no significant difference in sensitivity and specificity.
CONCLUSION: VMI 40 keV in dual-layer spectral detector CT can significantly improve image quality, allowing contrast dose reduction in infants and children with complex CHD without compromising diagnostic performance.
引用
- Cao X, Hu W, Li J, et al. Feasibility of reducing the contrast dose in infants and children with complex congenital heart disease using virtual monoenergetic images on dual-layer spectral detector computed tomography. Pediatr Radiol. 2026. PMID: 41984156. doi:10.1007/s00247-026-06599-x
供执业医师工作参考，不替代临床判断；数值与分级以指南原文为准。