Left Ventricular Mass Measurements in Patients using Real Time Echocardiography

左室肥厚是心脏病患者预后的重要指标。目前的技术定量左室质量，包括M型和二维超声心动图，只允许有限的评估左室肥大。实时三维超声心动图（RT 3D echo）是一种提供瞬时容积心脏图像的新技术。在图像欠佳的患者中，静脉注射造影剂可使左心室腔显影，并改善腔内清晰度。本研究旨在确定使用磁共振成像（MRI）作为参考标准的对比增强RT 3D回波测量LV质量的准确性。为此，43名患有不同心脏疾病的患者（年龄：56 ± 16岁; 26名男性和17名女性）在同一天随机接受了RT 3D回波和多相屏气电影GRE MRI检查。在外周静脉注射0.05 ml/kg EchoGen（一种基于十二碳戊烷的超声造影剂（Sonus Pharmaceuticals））后采集RT 3D回波图像。使用交互式辅助手动跟踪方法从RT 3D回波图像离线计算LV质量，以重建心内膜和心外膜表面。由对其他技术结果不知情的独立观察者分析图像。通过MRI测量的LV质量范围为105 - 373 g（平均值+/-SD：193+/-67）。左室质量的RT 3D回波测量与MRI获得的结果密切相关（r=0.93; y=13.7+0.89x; SEE=22.8; p<0.0001）。测量值之间的平均绝对差为19？16 g（10+/-8%的MRI衍生LV质量）。因此，对比增强的RT 3D回波准确地预测了人类的LV质量。因此，这种方法可能是有用的定量评估左心室肥大的心脏病人。- 三维超声心动图;左心室肥大;心肌-人类受试者

Left ventricular (LV) hypertrophy is an important prognostic indicator in patients with heart disease. Current techniques to quantitate LV mass, including M-mode and two-dimensional echocardiography, only allow a limited assessment of LV hypertrophy. Real-time three-dimensional echocardiography (RT3D echo) is a novel technique that provides instantaneous volumetric cardiac images. In patients with suboptimal images, intravenous contrast agents provide LV cavity opacification and improve endocardial definition. The present study aimed to determine the accuracy of LV mass measurements with contrast-enhanced RT3D echo using magnetic resonance imaging (MRI) as reference standard. To this purpose, 43 patients (age: 56+/-16 years; 26 men and 17 women) with different cardiac conditions underwent RT3D echo and multiphase breathhold cine GRE MRI examinations in random order on the same day. RT3D echo images were acquired after the peripheral intravenous injection of 0.05 ml/kg of EchoGen, a dodecafluoropentane-based ultrasound contrast agent (Sonus Pharmaceuticals). Off-line calculation of LV mass from RT3D echo images was performed using an interactive aided manual tracing method to reconstruct the endocardial and epicardial surfaces. Images were analyzed by independent observers blinded to the results of the other technique. LV mass measurements by MRI ranged from 105 to 373 g (mean+/-SD: 193+/-67). RT3D echo measurements of LV mass strongly correlated with those obtained by MRI (r=0.93; y=13.7+0.89x; SEE=22.8; p<0.0001). Mean absolute difference between measurements was 19?16 g (10+/-8% of MRI-derived LV mass). Thus, contrast-enhanced RT3D echo accurately predicts LV mass in humans. This method may therefore be useful for the quantitative assessment of LV hypertrophy in cardiac patients. - three-dimensional echocardiography; left ventricular hypertrophy; myocardium - Human Subjects