Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu, Japan.
Department of Cardiology and Nephrology, Mie University Graduate School of Medicine, Tsu, Japan.
JACC Cardiovasc Imaging. 2018 Jan;11(1):48-59. doi: 10.1016/j.jcmg.2017.04.006. Epub 2017 Jun 14.
The purpose of this study was to examine the histological correlation of native myocardial T1 and extracellular volume fraction (ECV) measurement at 3-T for the assessment of diffuse pathological changes in the myocardial tissue, including myocardial fibrosis and extracellular space in dilated cardiomyopathy (DCM).
Cardiac magnetic resonance T1 techniques allow the quantification of diffuse myocardial fibrosis. However, there are no definitive head-to-head studies of native T1 versus ECV for the detection, quantification, and characterization of pathological changes in the myocardial tissue in DCM by using histological samples for confirmation.
A total of 36 subjects with DCM (31 men, mean age 56 ± 16 years) underwent pre- and post-contrast T1 mapping as well as late gadolinium enhancement (LGE) cardiac magnetic resonance at 3-T. Biopsy samples were used for the quantification of collagen volume fraction using picrosirius red staining and an extracellular space component from hematoxylin and eosin-stained myocardium.
Nonischemic LGE was observed in 14 of 36 patients. Although patients with LGE had significantly greater biopsy-proven collagen volume fraction than those without LGE (21 ± 12% vs. 11 ± 8%; p < 0.01), there was substantial overlap of collagen volume fraction values between patients with and without LGE. Both native T1 value and ECV were similarly and significantly associated with biopsy-proven collagen volume fraction (r = 0.77 and r = 0.66, respectively; p < 0.05). Furthermore, ECV had a strong correlation with the biopsy-proven extracellular space component (r = 0.86), whereas native T1 had only a moderate correlation (r = 0.55). Interobserver and intraobserver reproducibility for native T1 and ECV were 0.89, 0.95, 0.96, and 0.98, respectively.
Native T1 exhibited comparable ability as ECV measurement in the detection and quantification of histological collagen volume fraction, with high reproducibility, and therefore diffuse myocardial fibrosis in DCM may be reliably assessed by native T1 mapping without the administration of gadolinium contrast agent. In addition, cardiac magnetic resonance-derived ECV showed excellent agreement with histological extracellular space.
本研究旨在探讨 3T 时心肌的 T1 值和细胞外容积分数（ECV）与原发性心肌组织病变的组织学相关性，包括扩张型心肌病（DCM）中的心肌纤维化和细胞外间隙。
心脏磁共振 T1 技术可定量评估弥漫性心肌纤维化。然而，尚无关于 T1 值与 ECV 在使用组织学样本进行确认的情况下，用于检测、量化和描述 DCM 心肌组织病理性改变的头对头研究。
共 36 例 DCM 患者（31 名男性，平均年龄 56±16 岁）在 3T 上进行了对比前和对比后的 T1 映射以及钆延迟增强（LGE）心脏磁共振检查。使用天狼星红染色对活检样本进行胶原容积分数的定量，并使用苏木精和伊红染色的心肌对细胞外空间成分进行定量。
14 例患者存在非缺血性 LGE。尽管 LGE 患者的活检证实胶原容积分数明显高于无 LGE 患者（21±12%比 11±8%；p<0.01），但 LGE 患者和无 LGE 患者的胶原容积分数值存在显著重叠。心肌 T1 值和 ECV 均与活检证实的胶原容积分数显著相关（r=0.77 和 r=0.66；p<0.05）。此外，ECV 与活检证实的细胞外空间成分具有很强的相关性（r=0.86），而心肌 T1 值仅具有中度相关性（r=0.55）。心肌 T1 值和 ECV 的观察者内和观察者间重复性分别为 0.89、0.95、0.96 和 0.98。
心肌 T1 值与 ECV 测量在检测和量化组织学胶原容积分数方面具有相当的能力，具有较高的可重复性，因此无需使用钆对比剂即可通过心肌 T1 映射可靠地评估 DCM 中的弥漫性心肌纤维化。此外，心脏磁共振衍生的 ECV 与组织学细胞外空间具有极好的一致性。
