应用对比增强 T1 测量法评估心肌细胞外容积时，换水对其测量值的影响：严重主动脉瓣狭窄患者的初步分析。

The impact of water exchange on estimates of myocardial extracellular volume calculated using contrast enhanced T measurements: A preliminary analysis in patients with severe aortic stenosis.

机构信息

Biomedical Imaging, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK.

Department of Medical Physics & Engineering, Leeds Teaching Hospitals NHS Trust, Leeds, UK.

出版信息

Magn Reson Med. 2024 Apr;91(4):1637-1644. doi: 10.1002/mrm.29956. Epub 2023 Dec 1.

DOI:10.1002/mrm.29956

PMID:38041477

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10872615/

Abstract

PURPOSE

Guidelines recommend measuring myocardial extracellular volume (ECV) using T -mapping before and 10-30 min after contrast agent administration. Data are then analyzed using a linear model (LM), which assumes fast water exchange (WX) between the ECV and cardiomyocytes. We investigated whether limited WX influences ECV measurements in patients with severe aortic stenosis (AS).

METHODS

Twenty-five patients with severe AS and 5 healthy controls were recruited. T measurements were made on a 3 T Siemens system using a multiparametric saturation-recovery single-shot acquisition (a) before contrast; (b) 4 min post 0.05 mmol/kg gadobutrol; and (c) 4 min, (d) 10 min, and (e) 30 min after an additional gadobutrol dose (0.1 mmol/kg). Three LM-based ECV estimates, made using paired T measurements (a and b), (a and d), and (a and e), were compared to ECV estimates made using all 5 T measurements and a two-site exchange model (2SXM) accounting for WX.

RESULTS

Median (range) ECV estimated using the 2SXM model was 25% (21%-39%) for patients and 26% (22%-29%) for controls. ECV estimated in patients using the LM at 10 min following a cumulative contrast dose of 0.15 mmol/kg was 21% (17%-32%) and increased significantly to 22% (19%-35%) at 30 min (p = 0.0001). ECV estimated using the LM was highest following low dose gadobutrol, 25% (19%-38%).

CONCLUSION

Current guidelines on contrast agent dose for ECV measurements may lead to underestimated ECV in patients with severe AS because of limited WX. Use of a lower contrast agent dose may mitigate this effect.

摘要

目的

指南建议在对比剂给药前和给药后 10-30 分钟使用 T 映射测量心肌细胞外容积（ECV）。然后使用线性模型（LM）分析数据，该模型假设 ECV 和心肌细胞之间的水交换速度很快（WX）。我们研究了严重主动脉瓣狭窄（AS）患者中有限的 WX 是否会影响 ECV 测量。

方法

招募了 25 名严重 AS 患者和 5 名健康对照者。在 3 T Siemens 系统上使用多参数饱和恢复单次采集（a）在对比前；（b）在 0.05 mmol/kg 钆布醇后 4 分钟；（c）在 4 分钟、（d）在 10 分钟和（e）在 30 分钟后使用额外的钆布醇剂量（0.1 mmol/kg）进行 T 测量。比较了使用配对 T 测量（a 和 b）、（a 和 d）和（a 和 e）进行的三种基于 LM 的 ECV 估计与使用所有 5 个 T 测量值和考虑 WX 的两部位交换模型（2SXM）进行的 ECV 估计。

结果

使用 2SXM 模型估计的中位数（范围）ECV 患者为 25%（21%-39%），对照组为 26%（22%-29%）。在累积剂量为 0.15 mmol/kg 的对比剂后 10 分钟，使用 LM 在患者中估计的 ECV 为 21%（17%-32%），并在 30 分钟时显著增加至 22%（19%-35%）（p=0.0001）。在低剂量钆布醇后，使用 LM 估计的 ECV 最高，为 25%（19%-38%）。