MAGNETIC-RESONANCE IMAGING WITH RESPIRATORY GATING - TECHNIQUES AND ADVANTAGES
MAGNETIC-RESONANCE IMAGING WITH RESPIRATORY GATING - TECHNIQUES AND ADVANTAGES
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DOI：
10.2214/ajr.143.6.1175
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发表时间：
1984-01-01
影响因子：
5
通讯作者：
HIGGINS, CB
中科院分区：
文献类型：
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作者：
EHMAN, RL;MCNAMARA, MT;HIGGINS, CB
呼吸运动是胸部和上腹部磁共振成像中的一个重要问题。这项研究评估了几种实用的呼吸门控方法。评价呼吸信号的获取方法、门控排序方法、检查持续时间、缩短检查时间的策略、门控图像的诊断质量以及呼吸门控对松弛时间测量的影响。在三种不同的呼吸信号采集装置中，上腹部周围放置的含有位移传感器的腰带被发现是最有效和实用的。实现了两种脉搏门控模式，以及一种心肺门控相结合的方法。门控方法是用幻影和人类志愿者测试的。呼吸门控的自旋条件模式优于更简单实现的触发模式，在该模式中自旋回波(SE)测序被中断。呼吸门控的时间惩罚取决于技术。无控制潮气呼吸的门控研究花费的时间是非门控研究的2-4倍。当自愿延长呼吸间隔时间时，门控研究可能只比不呼吸长30%-50%。呼吸门控显著降低了呼吸过程中移位器官的松弛时间测量的标准偏差。没有自旋条件的门控采集导致了T1弛豫时间的系统性误差，这是自旋条件门控所不存在的。呼吸门控是提高上腹部和胸部SE图像对比度和空间分辨率的一种实用有效的技术。呼吸门控对重复时间短的SE图像的改善尤为明显。
Respiratory motion is an important problem in magnetic resonance imaging (MRI) of the thorax and upper abdomen. This study assessed several approaches for practical respiratory gating. Methods of acquiring respiratory signals, gated sequencing methods, duration of examination, strategies for reducing examination time, diagnostic quality of gated images, and the influence of respiratory gating on relaxation time measurements were evaluated. Of 3 different devices for acquiring the respiratory signal, a belt containing a displacement transducer placed around the upper abdomen was found to be most effective and practical. Two pulse-gating modes were implemented, as well as a method for combining cardiac and respiratory gating. Gating methods were tested using phantoms and human volunteers. A spin-conditioned mode of respiratory gating was superior to a more simply implemented triggered mode in which spin-echo (SE) sequencing was interrupted. The time penalty for respiratory gating is technique-dependent. Gated studies with uncontrolled tidal breathing took 2-4 times longer than nongated studies. When the time between respirations was voluntarily prolonged, gated studies could be only 30%-50% longer than nongated. The standard deviation of relaxation-time measurements for organs that are displaced during respirations was substantially reduced by respiratory gating. Gating acquisition without spin-conditioning caused systematic errors in T1 relaxation times that were not present with spin-conditioned gating. Respiratory gating is a practical and useful technique for improving the contrast and spatial resolution of SE images of the upper abdomen and chest. SE images produced with short repetition times were particularly improved by respiratory gating.