儿童胸部CT剂量优化：70 kV与100 kV锡滤过下能量积分与光子计数CT的图像质量与剂量比较
本研究通过1岁儿童体模和121例儿童胸部CT回顾性数据，比较能量积分CT与光子计数CT在70 kV和100Sn协议下的辐射剂量与图像质量。体模显示100Sn协议下PCCT较EICT的CTDIvol和有效剂量降低约66%，但临床回顾中PCCT剂量显著高于EICT（0.23 vs 0.17 mGy），同时客观和主观图像质量均显著更优。结论认为PCCT在维持图像质量下可实现显著剂量降低，尤其100Sn协议，需转化至临床实践。
要点
- 100Sn协议下PCCT体模CTDIvol较EICT降低约66%，但临床回顾中PCCT剂量反而更高。
- PCCT临床图像质量（SNR和Likert评分）显著优于EICT，提示可在更低剂量下达到同等图像质量。
- 70 kV下两种扫描仪剂量相似，腹部屏蔽在70 kV更有效，100Sn野外散射更大。
核心结论
- 体模研究显示PCCT在儿童胸部CT中可实现显著剂量降低并维持图像质量，尤其使用100Sn协议。
- 临床回顾性数据显示PCCT剂量高于EICT但图像质量更优，提示存在临床剂量优化空间。
研究设计与样本
- 体模研究：使用1岁儿童拟人体模，在70 kV和100Sn协议下比较EICT与PCCT的CTDIvol、DLP、器官剂量系数和有效剂量（ICRP 103）。
- 临床回顾：121例儿童胸部CT（PCCT 66例，EICT 55例；年龄1-149月），均采用100Sn协议，回顾性评估图像质量、有效剂量和体型特异性剂量估计。
关键影像表现/征象
- 体模中100Sn协议CTDIvol较70 kV降低60-80%。
- 70 kV下EICT与PCCT剂量相似；100Sn下PCCT的CTDIvol和有效剂量较EICT低约66%。
- 器官剂量系数两者相当；腹部屏蔽在70 kV更有效，100Sn在野外散射更大。
- 临床数据中PCCT剂量显著高于EICT（0.23 mGy ± 0.07 mGy vs. 0.17 mGy ± 0.09 mGy，p=0.0002）。
- PCCT的SNR显著优于EICT（软组织1.02 vs. 0.35；肺6.97 vs. 4.30，p<0.0001），主观Likert评分也显著更优（软组织2.43 vs. 2.65；肺1.6 vs. 2.18）。
诊断标准与关键数值
- 体模研究以恒定图像质量为条件比较剂量。
- 临床图像质量采用SNR和Likert评分评估。
- 有效剂量基于ICRP 103计算。
临床应用与阅片要点
- 儿童胸部CT可优先考虑PCCT结合100Sn协议以降低剂量。
- 临床中需注意PCCT实际剂量可能高于EICT，应结合图像质量需求优化协议。
- 70 kV下注意腹部屏蔽的有效性，100Sn下注意野外散射防护。
局限性
- 临床部分为回顾性研究，非随机对照。
- 体模研究仅使用1岁儿童体模，结论外推需谨慎。
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
OBJECTIVE: Pediatric thoracic imaging requires radiation dose optimization. Common strategies include protocols with low (70 kV) or medium tube voltages (100 kV) with tin filtration (100Sn). Photon-Counting CT (PCCT) promises further dose reduction without compromising image quality. This study compares radiation dose and image quality between energy-integrating CT (EICT) and PCCT, using thermoluminescent dosimeter (TLD) measurements and clinical data.
MATERIALS AND METHODS: CTDIvol, DLP, organ dose coefficients, and effective doses (ICRP 103) were analyzed at constant image quality for 70 kV and 100Sn protocols on both CT systems using an anthropomorphic phantom of a one-year-old. Additionally, 121 pediatric chest CTs (PCCT: 66, EICT 55; ages 1 - 149 months) with 100Sn protocol were retrospectively evaluated for image quality, effective dose and size-specific dose estimates.
RESULTS: The phantom study demonstrates that CTDIvol values with 100Sn were 60-80% lower than with 70 kV for both scanners. At 70 kV, doses were similar between EICT and PCCT. For 100Sn, PCCT achieved ∼66% lower CTDIvol and effective doses than EICT. Organ dose coefficients were comparable. Abdominal shielding was more effective at 70 kV, while 100Sn exhibited greater scatter outside the field. The retrospective analysis of clinical data revealed that doses were significantly higher for PCCT than EICT (0.23 mGy ± 0.07 mGy vs. 0.17 mGy ± 0.09 mGy, p = 0.0002). At the same time both objective (SNR) and subjective (Likert score) image quality indicator were significantly better for PCCT (SNR 1.02 vs. 0.35 for soft tissue and 6.97 vs. 4.30, p < 0.0001 for lung; Likert score 2.43 vs. 2.65 for soft tissue, 1.6 vs. 2.18 for lung), demonstrating the potential for clinical dose optimization.
CONCLUSION: The phantom study showed that PCCT enables significant dose reduction in pediatric chest CT while maintaining image quality, especially with 100Sn protocols. This needs to be transferred to clinical practice to decrease pediatric radiation exposure.
引用
- Kunert P, Weis M, Schlattl H, et al. Dose optimization for pediatric chest CT: a comparative study of energy-integrating and photon-counting detector CT using 70 kV and 100 kV protocols with tin filtration regarding image quality and dose exposure. Eur J Radiol. 2026. PMID: 42107145. doi:10.1016/j.ejrad.2026.112900
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。