Department of Cardiovascular Sciences, University of Leicester and Cardiovascular Theme, NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom; John Walls Renal Unit, University Hospitals of Leicester, UK.
Department of Cardiovascular Sciences, University of Leicester and Cardiovascular Theme, NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom.
Eur J Radiol. 2021 Jul;140:109748. doi: 10.1016/j.ejrad.2021.109748. Epub 2021 May 1.
Myocardial native T1 is a potential measure of myocardial fibrosis, but concerns remain over the potential influence of myocardial edema to increased native T1 signal in subjects prone to fluid overload. This study describes differences in native T2 (typically raised in states of myocardial edema) and native T1 times in patients on hemodialysis by comparing native T1 and native T2 times between subjects on hemodialysis to an asymptomatic control group. Reproducibility of these sequences was tested.
Subjects were recruited prospectively and underwent 3 T-cardiac MRI with acquisition of native T1 and native T2 maps. Between group differences in native T1 and T2 maps were assessed using one-way ANOVAs. 30 subjects underwent test-retest scans within a week of their original scan to define sequence reproducibility.
261 subjects completed the study (hemodialysis n = 124, control n = 137). Native T1 times were significantly increased in subjects on hemodialysis compared to control subjects (1259 ms ± 51 vs 1212 ms ± 37, p < 0.01). There was no difference in native T2 times between subjects on hemodialysis and control subjects (39.5 ms ± 2.5 vs 39.5 ms ± 2.3, p = 0.9). These differences were unchanged after adjustment for relevant baseline differences (age, sex and hemoglobin). Inter-study reproducibility for native T1 and T2 mapping was excellent (coefficient of variability 0.9 % and 2.6 % respectively).
The increased native T1 signal demonstrated in subjects on hemodialysis occurs independently of differences in native T2 and the two parameters are not orthogonal. Elevated native T1 in patients on hemodialysis may be driven by water related to myocardial fibrosis rather than edema from volume overload.
心肌固有 T1 是心肌纤维化的潜在测量指标，但对于易发生液体超负荷的患者中，心肌水肿对固有 T1 信号的潜在影响仍存在担忧。本研究通过比较血液透析患者与无症状对照组之间的固有 T1 和固有 T2 时间，描述了血液透析患者的固有 T2（通常在心肌水肿状态下升高）和固有 T1 时间的差异。测试了这些序列的重现性。
前瞻性招募受试者，并进行 3T 心脏 MRI 检查，获取固有 T1 和固有 T2 图谱。使用单向方差分析评估组间固有 T1 和 T2 图谱的差异。30 名受试者在其原始扫描后一周内进行了测试-复测扫描，以确定序列的可重复性。
261 名受试者完成了研究（血液透析组 n=124，对照组 n=137）。与对照组相比，血液透析患者的固有 T1 时间明显增加（1259ms±51 vs 1212ms±37，p<0.01）。血液透析患者和对照组之间的固有 T2 时间没有差异（39.5ms±2.5 vs 39.5ms±2.3，p=0.9）。调整相关基线差异（年龄、性别和血红蛋白）后，这些差异仍然不变。固有 T1 和 T2 图谱的组内研究可重复性非常好（变异性系数分别为 0.9%和 2.6%）。
在血液透析患者中观察到的固有 T1 信号增加独立于固有 T2 的差异，并且这两个参数不是正交的。血液透析患者中升高的固有 T1 可能是由与心肌纤维化相关的水驱动的，而不是由容量超负荷引起的水肿。
