Fu Hang, Yan Mei, Yang Xue, Xu Ke, Xu Ting, Liu Lini, Li Muhan, Zeng Jiangyao, Zhang Yunan, Zhang Yilin, Tian Wenjie, Lin Jing, Guo Yingkun, Zhang Hongding, Xu Huayan
Department of Radiology, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China.
Department of Pediatric Hematology, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China.
Quant Imaging Med Surg. 2025 Mar 3;15(3):1938-1949. doi: 10.21037/qims-24-1769. Epub 2025 Feb 26.
The cardiac magnetic resonance (CMR) T2* mapping technique is widely used to quantify myocardial iron and assess iron overload in patients with transfusion-dependent thalassemia (TDT). However, the value of T2 mapping in detecting iron overload and its consistency with T2* mapping in the myocardium of pediatric patients are unknown. Thus, this study sought to explore the utility and feasibility of using T2 mapping to assess iron overload, and to provide an alternative non-invasive method for the assessment of iron overload in clinical practice.
Vitro iron-water phantom models with different iron concentrations were used to analyze the correlation between the T2 and T2* values. In total, 113 TDT pediatric patients were prospectively enrolled in the study and underwent CMR examinations using a Philips 1.5T scanner, and T2 and T2* mapping of the short-axis of the left ventricle were performed. Pearson correlation analyses, Bland-Altman plots, the Student's -test or Mann-Whitney test, Receiver operating characteristic (ROC) curve analyses, and intraclass correlation coefficient (ICC) were applied to analyze the data.
Excellent negative correlations were found between the actual iron concentration and the measured T2* (r=-0.919, P=0.003) and T2 values (r=-0.888, P=0.008) of the vitro iron-water phantom models. Additionally, the measured T2* and T2 values of the phantom models were positively correlated (r=0.997, P<0.001). Bland-Altman plots revealed that the T2* and T2 values showed good agreement at the basal, middle, and apical levels of the left ventricle short-axis. The areas under the ROC curves for the diagnosis of myocardial iron overload by T2 mapping in the basal, middle, and apical segments were 0.78, 0.95, and 0.89, respectively.
The T2 mapping technique may serve as an alternative and complementary method to the T2* mapping technique in assessing iron overload in TDT patients, which provides a new use of routine T2 mapping.
心脏磁共振（CMR）T2* 成像技术被广泛用于量化输血依赖型地中海贫血（TDT）患者的心肌铁含量并评估铁过载情况。然而，T2 成像在检测铁过载方面的价值以及其与儿科患者心肌中 T2* 成像的一致性尚不清楚。因此，本研究旨在探索使用 T2 成像评估铁过载的实用性和可行性，并为临床实践中评估铁过载提供一种替代性的非侵入性方法。
使用具有不同铁浓度的体外铁水模型分析 T2 和 T2* 值之间的相关性。总共 113 名 TDT 儿科患者前瞻性纳入本研究，并使用飞利浦 1.5T 扫描仪进行 CMR 检查，同时对左心室短轴进行 T2 和 T2* 成像。应用 Pearson 相关性分析、Bland - Altman 图、Student's t 检验或 Mann - Whitney 检验、受试者操作特征（ROC）曲线分析以及组内相关系数（ICC）来分析数据。
体外铁水模型的实际铁浓度与测量的 T2* 值（r = -0.919，P = 0.003）和 T2 值（r = -0.888，P = 0.008）之间存在极好的负相关性。此外，模型的测量 T2* 值和 T2 值呈正相关（r = 0.997，P < 0.001）。Bland - Altman 图显示，T2* 值和 T2 值在左心室短轴的基底、中间和心尖水平具有良好的一致性。在基底、中间和心尖节段通过 T2 成像诊断心肌铁过载的 ROC 曲线下面积分别为 0.78、0.95 和 0.89。
T2 成像技术可作为 T2* 成像技术在评估 TDT 患者铁过载方面的一种替代和补充方法，这为常规 T2 成像提供了新的用途。
