Saremi Farhood, Grizzard John D, Kim Raymond J
Department of Radiological Sciences, Division of Cardiothoracic Imaging, University of California Irvine, UCI Medical Center, 101 City Dr S, Route 140, Orange, CA 92868, USA.
Radiographics. 2008 Jul-Aug;28(4):1161-87. doi: 10.1148/rg.284065718.
With ongoing technical advances in magnetic resonance (MR) imaging, the clinical demand for cardiac MR evaluations has been increasing. Cardiac MR imaging techniques have evolved from traditional spin-echo sequences to breath-hold spoiled gradient-echo and balanced steady-state free precession sequences. The most recently developed techniques allow evaluation of myocardial function, perfusion, and viability; coronary angiography; flow quantification; and standard morphologic assessments. However, even with the most sophisticated acquisition techniques, artifacts commonly occur at cardiac MR imaging. Knowledge of the origin, imaging appearance, and significance of these artifacts is essential to avoid misinterpreting them as true lesions. Some artifacts are caused by simple errors in positioning of the patient, coil, or electrocardiographic leads; radiofrequency interference from nearby electronic equipment; or metallic objects within the magnetic field. Others are directly related to a specific MR imaging sequence or technique. Accelerated imaging techniques such as parallel imaging, which are used to shorten acquisition and breath-hold times in cardiac evaluations, are particularly vulnerable to artifacts. If an artifact severely degrades image quality, the acquisition should be repeated with appropriate adjustments to decrease or eliminate the problem.
随着磁共振（MR）成像技术的不断进步，心脏MR评估的临床需求一直在增加。心脏MR成像技术已从传统的自旋回波序列发展到屏气扰相梯度回波和平衡稳态自由进动序列。最新开发的技术能够评估心肌功能、灌注和存活情况；进行冠状动脉造影；进行血流定量分析；以及进行标准的形态学评估。然而，即使采用最先进的采集技术，心脏MR成像时通常也会出现伪影。了解这些伪影的起源、成像表现及意义对于避免将其误判为真正的病变至关重要。一些伪影是由患者、线圈或心电图导联定位的简单错误、附近电子设备的射频干扰或磁场内的金属物体引起的。其他伪影则与特定的MR成像序列或技术直接相关。加速成像技术，如用于缩短心脏评估中采集和屏气时间的并行成像，特别容易出现伪影。如果伪影严重降低图像质量，应进行适当调整后重复采集，以减少或消除问题。
