Influence of the cardiac cycle on velocity selective and acceleration selective arterial spin labeling
Influence of the cardiac cycle on velocity selective and acceleration selective arterial spin labeling
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DOI：
10.1002/mrm.27973
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发表时间：
2020-03-01
影响因子：
3.3
通讯作者：
van Osch, Matthias J. P.
中科院分区：
文献类型：
--
作者：
Franklin, Suzanne L.;Schmid, Sophie;van Osch, Matthias J. P.
目的：在本研究中，研究了心动周期对速度选择性 (VSASL) 和加速度选择性动脉自旋标记 (AccASL) 模块产生的标记量的影响。方法：开发了一个短 PLD 序列，其中单个 VSASL 或 AccASL 模块之前有 pCASL 标记以分离动脉血池。使用具有相似心脏相位和测量时间的标签/控制图像执行 ASL 减法，然后在 10 个心脏相位箱中进行回顾性分组。使用置换检验评估心动周期中的 ASL 信号变化并测试显着性。结果：VSASL 和 AccASL 显示心动周期中的显着动脉信号波动分别高达 36% 和 64%，主要发生在含有大动脉的区域。 pCASL 还显示出显着的信号波动，动脉信号波动高达 25%。原始标签/对照图像证实观察到的信号波动是由心动周期期间产生的标签量引起的，而不是流入效应，因为原始图像并不都显示出相同的心脏相位依赖性。没有发现心动周期对灰质 ASL 信号有显着影响。结论：对于空间非选择性 ASL 序列，发现心动周期对生成的标签有显着影响。因此，为了独立于心动周期，需要获取足够的平均值。或者，这些发现对于量化血管树更远端的搏动来说可能非常有趣。
Purpose: In this study, the influence of the cardiac cycle on the amount of label produced by a velocity-selective (VSASL) and acceleration-selective arterial spin labeling (AccASL) module was investigated.Methods: A short-PLD sequence was developed where a single VSASL- or AccASL-module was preceded by pCASL labeling to isolate the arterial blood pool. ASL subtraction was performed with label/control images with similar cardiac phase and time-of-measurement, followed by retrospective binning in 10 cardiac phase bins. ASL signal variation over the heart cycle was evaluated and tested for significance using a permutation test.Results: VSASL and AccASL showed significant arterial signal fluctuations over the cardiac cycle of up to similar to 36% and similar to 64%, respectively, mainly in areas containing large arteries. pCASL also showed significant signal fluctuations, of up to similar to 25% in arteries. Raw label/control images confirmed that the observed signal fluctuations were caused by the amount of label produced during the cardiac cycle, rather than inflow-effects, because the raw images did not all show equal cardiac phase dependence. No significant effects of the cardiac cycle were found on the gray matter ASL-signal.Conclusion: Significant influence of the cardiac cycle on the generated label was found for spatially nonselective ASL-sequences. Hence, to become independent of the cardiac cycle, sufficient averages need to be taken. Alternatively, these findings could be highly interesting for the purpose of quantifying pulsatility more distally in the vascular tree.