Relationship between motion of coronary arteries and diaphragm during free breathing: Lessons from real-time MR imaging
Relationship between motion of coronary arteries and diaphragm during free breathing: Lessons from real-time MR imaging
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DOI：
10.2214/ajr.172.4.10587147
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发表时间：
1999-04-01
影响因子：
5
通讯作者：
Manning, WJ
中科院分区：
文献类型：
--
作者：
Danias, PG;Stuber, M;Manning, WJ
OBJECTIVE.在自由呼吸冠状动脉MR血管造影术中经常使用横膈膜导航器，用于门控或前瞻性校正切片位置或两者。对于这样的方法，假设在整个呼吸周期中冠状动脉和动脉移位之间的恒定关系。本研究的目的是评价自由呼吸时冠状动脉运动与冠状动脉运动之间的关系。对12名健康志愿者进行了实时回波平面磁共振成像，每个序列获得30个连续图像（每个心动周期一次），包括左冠状动脉主干和两个半膈的圆顶，（相对于等中心点），并分析了3，5和7 mm的有效成像门控窗口（分别从呼气末位置的0-3、0-5和0-7 mm的呼吸偏移）。尽管对于所有脑门控窗，右膈和左冠状动脉主干位移相关的平均斜率约为0.6，但我们也发现个体志愿者之间存在很大的变异性。线性回归斜率为0.17 ~ 0.93，相关系数r（2）为0.04 ~ 0.87。在自由呼吸期间，冠状动脉和血管性呼吸运动之间的关系存在广泛的个体差异。因此，使用磁共振导航器位置进行前瞻性切片校正的冠状动脉MR血管造影方法可以受益于患者特定的校正因子。或者，冠状动脉MR血管造影术可能受益于使用左心室导航仪对心脏和冠状动脉的呼吸位移进行更直接的评估。
OBJECTIVE. Diaphragmatic navigators are frequently used in free-breathing coronary MR angiography, either to gate or prospectively correct slice position or both. For such approaches, a constant relationship between coronary and diaphragmatic displacement throughout the respiratory cycle is assumed. The purpose of this study was to evaluate the relationship between diaphragmatic and coronary artery motion during free breathing.SUBJECTS AND METHODS. A real-time echoplanar MR imaging sequence was used in 12 healthy volunteers to obtain 30 successive images each (one per cardiac cycle) that included the left main coronary artery and the domes of both hemidiaphragms, The coronary artery and diaphragm positions (relative to isocenter) were determined and analyzed for effective diaphragmatic gating windows of 3, 5, and 7 mm (diaphragmatic excursions of 0-3, 0-5, and 0-7 mm from the end-expiratory position, respectively).RESULTS. Although the mean slope correlating the displacement of the right diaphragm and the left main coronary artery was approximately 0.6 for all diaphragmatic gating windows, we also found great variability among individual volunteers. Linear regression slopes varied from 0.17 to 0.93, and r(2) values varied from .04 to .87.CONCLUSION. Wide individual variability exists in the relationship between coronary and diaphragmatic respiratory motion during free breathing. Accordingly, coronary MR angiographic approaches that use diaphragmatic navigator position for prospective slice correction may benefit from patient-specific correction factors. Alternatively, coronary MR angiography may benefit from a more direct assessment of the respiratory displacement of the heart and coronary arteries, using left ventricular navigators.