优化增强CT主动脉钙化评估：探索心血管评分所需的HU阈值
本研究为单中心回顾性研究，纳入1125例行三期CT血管造影的患者，旨在确定增强CT上量化主动脉钙化的最佳HU阈值。结果显示，静脉期固定300 HU阈值与平扫Agatston评分相关性最强（胸主动脉ρ=0.93，腹主动脉ρ=0.92），预测准确性最高（R²=0.66和0.68）；动脉期需更高阈值（胸主动脉900 HU，腹主动脉800 HU）。静脉期300 HU阈值可作为无平扫图像时估算主动脉钙化的实用替代指标。
要点
- 静脉期300 HU阈值与Agatston评分相关性最强，胸主动脉ρ=0.93、腹主动脉ρ=0.92。
- 静脉期300 HU阈值预测准确性最高，胸主动脉R²=0.66、腹主动脉R²=0.68。
- 动脉期需更高阈值，胸主动脉900 HU（R²=0.51）、腹主动脉800 HU（R²=0.45）。
核心结论
- 静脉期固定300 HU阈值可作为无平扫图像时估算主动脉钙化的实用替代指标。
研究设计与样本
- 回顾性单中心研究，纳入1125例（女344例，男781例）行三期CT血管造影的患者。
- 以平扫Agatston评分为参考标准，比较固定阈值（100-900 HU）和动态阈值在动脉期和静脉期的表现。
- 采用相关性分析、线性回归和Bland-Altman分析评估一致性和预测性能。
诊断标准与关键数值
- 静脉期300 HU阈值与Agatston评分相关性最强：胸主动脉Spearman ρ=0.93，腹主动脉ρ=0.92（均p<0.001）。
- 静脉期300 HU阈值预测准确性最高：胸主动脉R²=0.66，腹主动脉R²=0.68。
- 动脉期最佳阈值：胸主动脉900 HU（R²=0.51，p<0.001），腹主动脉800 HU（R²=0.45，p<0.001）。
- 动态阈值法的R²值低于最佳固定阈值。
- Bland-Altman分析显示静脉期300 HU阈值在低钙负荷时偏倚小，但高Agatston评分时一致性界限增宽且低估程度增加。
临床应用与阅片要点
- 无平扫图像时，可考虑用静脉期300 HU阈值估算主动脉钙化负荷。
- 动脉期评估需采用更高阈值（胸主动脉900 HU、腹主动脉800 HU），否则相关性下降。
- 高钙负荷时静脉期300 HU阈值可能低估钙化程度，报告时应谨慎解读。
局限性
- 回顾性单中心研究设计。
- 高Agatston评分时静脉期300 HU阈值低估程度增加，一致性界限增宽。
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
PURPOSE: Cardiovascular disease is the leading global cause of death, and vascular calcification is a key marker of atherosclerotic burden. This study aimed to determine optimal Hounsfield Unit (HU) thresholds for quantifying aortic calcification on contrast-enhanced CT.
MATERIAL AND METHODS: This retrospective single-center study included 1125 patients (344 women, 781 men) who underwent triphasic CT angiography. Fixed (100-900 HU) and dynamic thresholds were applied to arterial and venous phases and compared with non-contrast Agatston scores. Correlation, linear regression and Bland-Altman analyses were used to assess agreement and predictive performance.
RESULTS: In the venous phase, the 300 HU threshold demonstrated the strongest correlation with the Agatston score (thoracic aorta Spearman's rank correlation coefficient ρ = 0.93; abdominal aorta: ρ = 0.92; all p < 0.001) and the highest predictive accuracy (R2 = 0.66 and 0.68). In the arterial phase, higher thresholds were required, with optimal performance at 900 HU for the thoracic aorta (R2 = 0.51, p < 0.001) and 800 HU for the abdominal aorta (R2 = 0.45, p < 0.001). Dynamic thresholding showed lower R2 values than optimal fixed thresholds. Bland-Altman analysis for the venous 300 HU threshold showed low bias at low calcium burden but widening limits of agreement and increasing underestimation at higher Agatston scores.
CONCLUSION: A fixed threshold of 300 HU in the venous phase may represent a pragmatic surrogate marker for estimating aortic calcification on contrast-enhanced CT when non-contrast imaging is unavailable.
引用
- Reschke P, Booz C, Wörtche K, et al. Improving aortic calcium assessment in contrast-enhanced CT: exploring Hounsfield Unit thresholds for cardiovascular scoring. Radiol Med. 2026. PMID: 42201642. doi:10.1007/s11547-026-02223-y
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。