动态增强MRI与MAG-3肾闪烁显像评估儿童分肾功能对比
回顾性纳入23例患儿，比较动态增强MRI与MAG-3肾闪烁显像测得的分肾功能（DRF）。两种方法高度线性相关、一致性良好且无系统性偏倚，但测量变异度提示在手术决策阈值附近需谨慎解读。建议肾积水肾脏的MAG-3分析采用C形本底校正以优化方法间一致性。
要点
- DCE-MRI与MAG-3测得的DRF高度相关（r=0.872），一致性相关系数0.870
- 78.3%（18/23）病例的DRF差异在预设临床可接受范围±10%内
- 手术决策阈值附近的DRF值需谨慎解读，因测量变异度较大
核心结论
- DCE-MRI与MAG-3闪烁显像在儿童分肾功能评估中呈强线性相关和良好一致性，未检测到有临床意义的系统性或比例偏倚。
- 观察到的测量变异度提示：当DRF值接近手术决策阈值时，比较两种方法的结果需谨慎。
- 对于肾积水肾脏，推荐MAG-3分析采用C形本底校正，以优化方法间的一致性。
研究设计与样本
- 回顾性研究，纳入23例患儿（年龄3个月至20岁，平均8.3±7.4岁），在6个月内完成MR尿路造影协议中的DCE-MRI和MAG-3检查。
- DCE-MRI采用黄金角径向动态堆叠星采集与GRASP重建，并用双室示踪动力学模型分析肾滤过率。
- 以MAG-3闪烁显像为参考，分别采用默认本底（n=23）和C形本底（n=16，有原始数据者）分析DRF，用Bland-Altman分析、Pearson相关和一致性相关系数评估一致性。
诊断标准与关键数值
- 默认MAG-3本底分析（n=23）：平均DRF差异（MAG-3减DCE-MRI）为0.4%（95%CI -3.3%至4.2%），95%一致性界限为-16.7%至+17.5%，一致性相关系数0.870（95%CI 0.718-0.942）。
- 预设临床可接受范围±10%内，78.3%（18/23）病例的DRF差异落在此范围内，平均绝对差异为6.1%。
- C形本底校正亚组（n=16）：平均差异-2.3%（95%CI -6.7%至2.0%），一致性界限-18.3%至+13.6%，一致性相关系数0.845（95%CI 0.614-0.943）。
- Pearson相关在两种分析中均强：n=23时r=0.872（95%CI 0.719-0.945），n=16时r=0.866（95%CI 0.648-0.953），均P<0.001。
临床应用与阅片要点
- DCE-MRI可作为无辐射、高分辨率的替代方法评估儿童分肾功能，尤其适用于需多次随访的患儿。
- 阅片报告DRF时，应意识到DCE-MRI与MAG-3的测量差异可能达±10%以上，在手术决策阈值附近需结合临床和其他影像综合判断。
- 对肾积水肾脏，建议MAG-3分析采用C形本底校正，以提高与DCE-MRI的一致性。
局限性
- 回顾性研究，样本量较小（n=23），可能存在选择偏倚。
- C形本底校正亚组仅16例有原始数据，亚组分析效能有限。
- 未报告重复测量的一致性，测量变异度可能受操作者影响。
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: Measuring differential renal function (DRF) is critical for managing children with congenital and acquired urological diseases. MAG-3 renal scintigraphy is the most widely used clinical technique; dynamic contrast-enhanced MRI (DCE-MRI) provides a radiation-free and high-resolution alternative method for assessing DRF.
OBJECTIVE: To evaluate the agreement between DRF values derived from DCE-MRI and MAG-3 scintigraphy-derived DRF in pediatric patients.
MATERIALS AND METHODS: This retrospective study included 23 pediatric patients (age range, 3 months-20 years; mean±SD, 8.3±7.4 years) who underwent DCE-MRI embedded in MR urography (MRU) protocol and MAG-3 studies within 6 months. DCE-MRI was performed using a golden-angle radial dynamic stack-of-stars acquisition with golden-angle sparse parallel (GRASP) reconstruction, and analyzed the renal filtration rate with a two-compartment tracer kinetic model. DRF values from DCE-MRI were compared with those from MAG-3, using both default (n=23) and C-shaped background regions for MAG-3 analysis, where raw data were available (n=16). Agreement was evaluated using Bland-Altman analysis, Pearson and concordance correlations, and paired statistical tests.
RESULTS: With default MAG-3 background analysis (n=23), mean DRF difference (MAG-3 minus DCE-MRI) was 0.4% (95% CI, -3.3% to 4.2%), with 95% limits of agreement of -16.7% to +17.5%. Concordance correlation coefficient (CCC) was 0.870 (95% CI, 0.718-0.942). Within the pre-defined clinically acceptable margin of ±10%, 78.3% (18/23) of cases fell, with a mean absolute difference of 6.1%. With C-shaped background subtraction in the subset with available raw MAG-3 data (n=16), mean difference was -2.3% (95% CI, -6.7% to 2.0%), limits of agreement -18.3% to +13.6%, and CCC 0.845 (95% CI, 0.614-0.943). Pearson correlation was strong in both analyses (n=23: r=0.872, 95% CI, 0.719-0.945; n=16: r=0.866, 95% CI, 0.648-0.953; both P<0.001). No clinically significant systematic or proportional bias was detected in either analysis.
CONCLUSION: DCE-MRI demonstrates strong linear association and concordance with MAG-3 scintigraphy for pediatric differential renal function assessment with no clinically significant systematic bias, though the observed measurement variability indicates caution is warranted when comparing values near surgical decision thresholds. C-shaped background correction is recommended for MAG-3 in hydronephrotic kidneys to optimize inter-modality agreement.
引用
- Ariyurek C, Timms L, Cao X, et al. Comparison of dynamic contrast-enhanced MRI versus MAG-3 scintigraphy for differential renal function assessment in pediatric patients. Pediatr Radiol. 2026. PMID: 42053799. doi:10.1007/s00247-026-06624-z
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。