3D volume-selective turbo spin echo for carotid artery wall imaging with navigator detection of swallowing
3D volume-selective turbo spin echo for carotid artery wall imaging with navigator detection of swallowing
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DOI：
10.1002/jmri.20424
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发表时间：
2005-10-01
影响因子：
4.4
通讯作者：
Firmin, DN
中科院分区：
文献类型：
--
作者：
Crowe, LA;Keegan, J;Firmin, DN
目的：通过引入导航仪改善颈动脉壁三维容积选择性涡轮自旋回波(TSE)成像，减少吞咽伪影。材料与方法：图像采集采用西门子Magnetom Sonata 1.5T扫描仪。对6名健康志愿者进行了颈动脉三维容积选择性TSE扫描。放置在舌头后部的交叉对导航仪被用来检测吞咽和移动。测试了两种吞咽模式：1)在扫描时间的大约一半处，在k(Z)的中心处，单次吞咽；以及2)在整个扫描周期中尽可能频繁地重复吞咽。图像是在有导航器和没有导航器的情况下采集的，用于比较。4名独立盲观者对颈总动脉管壁的清晰度进行分级。结果：总体上，管腔内的信号强度较低，在导航控制的扫描上，模糊和重影减少。这种管腔信号强度的降低标志着黑血成像技术的进步。这些差异可能反映了由于当心率在吞咽时改变时被拒绝的循环，或者当使用导航器时组织的运动模糊/重影减少，或者这两种影响的组合所导致的双反转/血液抑制效率的提高。对图像质量的统计分析表明，导航扫描和非导航扫描之间存在显著差异，这是由四名独立、盲目的观察者得出的。对于这两种吞咽模式，导航者图像的平均得分比非导航者图像的平均得分高0.6(在0-5的评分范围内，0=看不到血管，5=良好的描绘和血液抑制)，所有观察者的P值都小于0.01。总体而言，中央吞咽扫描的得分高于重复的吞咽扫描。其中一个原因可能是吞咽时心率加快，在导航员返回正常接受位置后，这种情况通常会持续一到两个心跳周期。吞咽后心率增加的影响可能对双倒置血液抑制效率有影响。因此，即使导航员在吞咽运动中拒绝数据视图，反复吞咽增加的心率变化量也可能产生更大的不良影响。结论：在采集过程中吞咽会降低血管壁描绘的清晰度和血液抑制的表观效率。运动模糊和血液抑制质量都是可以通过使用导航器接受/拒绝方法来改善的因素。
Purpose: To improve 3D volume-selective turbo spin echo (TSE) carotid artery wall imaging by incorporating navigators to reduce artifacts caused by swallowing.Materials and Methods: Images were acquired on a Siemens Magnetom Sonata 1.5T scanner. 3D volume-selective TSE scans of the carotid arteries were acquired in six healthy volunteers. A cross-pair navigator placed on the back of the tongue was used to detect swallowing and movement. Two swallowing patterns were tested: 1) a single swallow approximately halfway through the scan time, at the center of k(z) and 2) repeated swallowing as often as possible throughout the scan period. Images were acquired with and without navigators for comparison. Signal intensity in the lumen was quantified for the quality of blood suppression, and the clarity of the vessel wall in the common carotid was ranked by four independent blinded observers.Results: In general, lower signal intensity was recorded in the lumen, and decreased blurring and ghosting were observed on scans with navigator control. This reduction in lumen signal intensity signifies an improvement in the black-blood imaging technique. The differences likely reflect the improved double inversion/blood suppression efficiency due to cycles being rejected when the heart rate changed at the point of swallowing, or decreased motional blurring/ghosting of tissue when the navigator is used, or a combination of these two effects. A statistical analysis of image quality showed a significant difference between navigated and non-navigated scans as scored by four independent, blinded observers. For both swallowing patterns, the mean score for the navigator images was on average 0.6 greater than that of non-navigator images (on a scoring scale of 0-5, where 0 = no vessel visible, and 5 = good delineation and blood suppression) and P-values for all observers were less than 0.01. Overall, the central swallow scans were scored higher than the repeated swallow scans. One reason for this may be the fact that the heart rate increased on swallowing, and this often lasted for one or two cardiac cycles after the navigator returned to the normal acceptance position. The effect of the increased heart rate after swallowing is likely to have an effect on double inversion blood suppression efficiency. Therefore, the increased amount of heart rate changes with repeated swallowing may have a greater adverse effect, even if the navigator rejects data views during the swallowing motion.Conclusion: The clarity of vessel wall delineation and the apparent efficiency of blood suppression are reduced by swallowing during acquisition. Both motion blurring and quality of blood suppression are factors that can be improved with the use of a navigator accept/reject method.