Department of Clinical Medicine, Jining Medical University, Jining 272000, Shandong, China.
Department of Radiology, Chenzhou First People's Hospital, Chenzhou 423000, Hunan, China.
Radiography (Lond). 2024 May;30(3):926-931. doi: 10.1016/j.radi.2024.04.005. Epub 2024 Apr 23.
Early diagnosis of patients with dilated cardiomyopathy (DCM) remains challenging. Cardiac MR can correlate myocardial changes with their pathological basis. There have been some previous studies on the effect of T1 mapping in DCM, but there is limited data on the incremental value of T2 mapping for DCM in routine clinical practice. This study will examine whether the combination of MRI T1 and T2 mapping offers greater advantages in the diagnosis of DCM.
The study included 28 patients with DCM and 21 healthy controls. CMR evaluation included late gadolinium enhancement (LGE), T1 mapping, extracellular volume (ECV) fraction and T2 mapping. The DCM group was divided into LGE (+) and LGE (-) subgroups. The main modes of LGE are subendocardial, midwall, subepicardial, or transmural. T1 values, T2 values, and ECV in the 16 segments myocardial levels were measured by post-processing software. Student's t-tests or Mann-Whitney U test was used to compare between two groups, and one-way ANOVA or Kruskal-Wallis H test was used to compare between multiple groups, with p values corrected by Bonferroni. The difference was considered statistically significant at P < 0.05. ROC curve analysis was used to compare the area under the curve (AUC) of each index and its combined value, and the cut-off value, sensitivity and specificity were determined by Jordan's index.
Mean native myocardial T1, ECV and T2 were significantly higher in the DCM group compared to controls (p ≤ 0.001, respectively). The best cut-off values for T1, T2 and ECV to discriminate DCM from controls were 1184 ms, 40.9 ms and 29.2%, respectively. The AUC of T1, ECV and T2 were 0.87, 0.89, and 0.83, respectively. The combined AUC of the three values was 0.96.
Native T1 value and ECV overcome some of the limitations of LGE, and the T2 helps to understand the extent of myocardial damage. The combination of T1 and T2 mapping techniques can reveal fibrotic and oedematous changes in the early stages of DCM, providing a more comprehensive assessment of DCM and better guidance for individualised clinical management of patients.
We suggest that the addition of T2 mapping to the routine CMR examination of patients with suspected DCM, and the combined assessment of T1mapping and T2 mapping can provide complementary information about the disease and improve the early diagnosis of DCM.
早期诊断扩张型心肌病（DCM）仍然具有挑战性。心脏磁共振（CMR）可以将心肌变化与其病理基础相关联。之前已经有一些关于 T1 映射在 DCM 中的作用的研究，但在常规临床实践中，关于 T2 映射对 DCM 的增量价值的数据有限。本研究将探讨 T1 和 T2 映射的组合是否在 DCM 的诊断中具有更大的优势。
该研究纳入 28 例 DCM 患者和 21 名健康对照者。CMR 评估包括晚期钆增强（LGE）、T1 映射、细胞外容积（ECV）分数和 T2 映射。DCM 组分为 LGE（+）和 LGE（-）亚组。LGE 的主要模式为心内膜下、中层、心外膜下或透壁。通过后处理软件测量 16 节段心肌水平的 T1 值、T2 值和 ECV。采用 Student's t 检验或 Mann-Whitney U 检验比较两组间差异，采用单因素方差分析或 Kruskal-Wallis H 检验比较多组间差异，P 值用 Bonferroni 校正。P<0.05 为差异有统计学意义。采用 ROC 曲线分析比较各指标及其联合值的曲线下面积（AUC），并通过 Jordan 指数确定最佳截断值、敏感性和特异性。
与对照组相比，DCM 组的心肌固有 T1、ECV 和 T2 值均显著升高（p≤0.001）。用于区分 DCM 与对照组的 T1、T2 和 ECV 的最佳截断值分别为 1184ms、40.9ms 和 29.2%。T1、ECV 和 T2 的 AUC 分别为 0.87、0.89 和 0.83，三者联合的 AUC 为 0.96。
固有 T1 值和 ECV 克服了 LGE 的一些局限性，而 T2 有助于了解心肌损伤的程度。T1 和 T2 映射技术的联合应用可以揭示 DCM 早期纤维化和水肿改变，为 DCM 提供更全面的评估，并为患者的个体化临床管理提供更好的指导。
我们建议在疑似 DCM 患者的常规 CMR 检查中增加 T2 映射，并对 T1 映射和 T2 映射进行联合评估，以提供有关疾病的互补信息，并提高 DCM 的早期诊断。
