Gastl Mareike, Gotschy Alexander, von Spiczak Jochen, Polacin Malgorzata, Bönner Florian, Gruner Christiane, Kelm Malte, Ruschitzka Frank, Alkadhi Hatem, Kozerke Sebastian, Manka Robert
Department of Cardiology, University Heart Center, University Hospital Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
Institute for Biomedical Engineering, University and ETH Zurich Gloriastrasse 35, 8092 Zurich, Switzerland.
Eur J Radiol Open. 2019 Feb 4;6:78-84. doi: 10.1016/j.ejro.2019.01.007. eCollection 2019.
Hypertrophic cardiomyopathy (HCM) is characterized by a heterogeneous morphology and variable prognosis. A mismatch between left ventricular mass (LVM) and microvascular circulation with corresponding relative ischemia has been implicated to cause myocardial replacement fibrosis that deteriorates prognosis. Besides parametric T1 mapping, Cardiovascular Magnetic Resonance (CMR) T2* mapping is able to identify ischemia as well as fibrosis in cardiac and extracardiac diseases. Therefore, we aimed to investigate the value of T2* mapping to characterize structural alterations in patients with HCM.
CMR was performed on a 1.5 T MR imaging system (Achieva, Philips, Best, Netherlands) using a 5-channel coil in patients with HCM (n = 103, 50.6 ± 16.4 years) and in age- and gender-matched controls (n = 20, 44.8 ± 16.9 years). T2* mapping (1 midventricular short axis slice) was acquired in addition to late gadolinium enhancement (LGE). T2* values were compared between patients with HCM and controls as well as between HCM patients with- and without fibrosis.
HCM patients showed significantly decreased T2* values compared to controls (26.2 ± 4.6 vs. 31.3 ± 4.3 ms, p < 0.001). Especially patients with myocardial fibrosis presented with decreased T2* values in comparison to those without fibrosis (25.2 ± 4.0 vs. 28.7 ± 5.3 ms, p = 0.003). A regression model including maximum wall thickness, LVM and T2* values provided good overall diagnostic accuracy of 80% to diagnose HCM with and without fibrosis.
In this study, parametric mapping identified lower T2* values in HCM patients compared to controls, especially in a sub-group of patients with myocardial fibrosis. As myocardial fibrosis has been suggested to influence prognosis of patients with HCM, T2* mapping may add information for identifying a higher risk sub-group of HCM patients.
肥厚型心肌病（HCM）具有形态异质性和预后多变的特点。左心室质量（LVM）与微血管循环不匹配并伴有相应的相对缺血，被认为会导致心肌替代性纤维化，从而使预后恶化。除了参数化T1成像，心血管磁共振（CMR）T2成像还能够识别心脏和心脏外疾病中的缺血以及纤维化。因此，我们旨在研究T2成像在表征HCM患者结构改变方面的价值。
在1.5T磁共振成像系统（Achieva，飞利浦，贝斯特，荷兰）上，使用5通道线圈对HCM患者（n = 103，50.6±16.4岁）以及年龄和性别匹配的对照组（n = 20，44.8±16.9岁）进行CMR检查。除了延迟钆增强（LGE）外，还采集了T2成像（1个心室中部短轴切片）。比较了HCM患者与对照组之间以及有和没有纤维化的HCM患者之间的T2值。
与对照组相比，HCM患者的T2值显著降低（26.2±4.6 vs. 31.3±4.3 ms，p <0.001）。特别是与没有纤维化的患者相比，有心肌纤维化的患者T2值降低（25.2±4.0 vs. 28.7±5.3 ms，p = 0.003）。一个包括最大壁厚、LVM和T2*值的回归模型对诊断有无纤维化的HCM具有80%的良好总体诊断准确性。
在本研究中，参数化成像显示HCM患者的T2值低于对照组，尤其是在有心肌纤维化的患者亚组中。由于心肌纤维化被认为会影响HCM患者的预后，T2成像可能会为识别HCM患者的高风险亚组提供更多信息。
