Variable tip angle slab selection pulses for carotid and cerebral time-of-flight MR angiography
Variable tip angle slab selection pulses for carotid and cerebral time-of-flight MR angiography
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用于颈动脉和大脑飞行时间 MR 血管造影的可变尖端角度平板选择脉冲
DOI：
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
M. Takahashi
中科院分区：
文献类型：
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作者：
I. Ikushima;Y. Korogi;T. Hirai;M. Takahashi
目的：确定飞行时间 MR 血管造影中可变尖端角度平板选择（倾斜优化非饱和激励，TONE）脉冲的最佳参数，以便对入口分区远端的血管产生最佳可视化。材料和方法：通过血流信号幅度的数学模型评估三维 (3D) 飞行时间 MR 血管造影中 TONE 脉冲的平均翻转角 (MFA) 和轮廓倾斜的影响。我们将计算出的血流信号与血流模型的信号以及 6 名正常志愿者的信号进行了比较。 3D 梯度回波图像 (TR/TE/30/7) 是通过 MFA 和剖面倾斜的单个变量获取的。模型的流速保持在15cm/s。在源图像上测量感兴趣区域。我们还评估了其他 5 名健康志愿者在使用和不使用 TONE 脉冲时获得的最大强度投影图像上的脑血管可视化。结果：模型和志愿者体内的血流信号变化与计算机数学预测和绘制的信号变化非常一致，因为每个参数都是不同的。较小 MFA 时的外周饱和度比较大 MFA 时更弱。较大的轮廓倾斜比较小的轮廓倾斜产生更明显的音调效果。添加 TONE 脉冲后，周围脑血管的可视化得到显着改善。结论：计算机模拟对于检查最佳 TONE 参数很有用。 TONE 脉冲显着改善了脑血管远端分支的可视化。
Objective: to determine the optimal parameters of variable tip angle slab selection (tilted optimized nonsaturating excitation, TONE) pulses in time-of-flight MR angiography, in order to produce the best visualization of vessels distal to the entry partition. Material and Methods: the influences of the mean flip angle (MFA) and the profile tilt of the TONE pulse in three-dimensional (3D) time-of-flight MR angiography were evaluated with a mathematical modeling of the flow signal amplitude. We compared the calculated flow signals with the signals from flow-phantom models and with those from 6 normal volunteers. 3D gradient echo images (TR/TE/30/7) were acquired with a single variable of the MFA and the profile tilt. the flow velocity of the phantom was maintained at 15 cm/s. Regions of interest were measured on the source images. We also evaluated the visualization of the cerebral vessels on maximum intensity projection images obtained with and without TONE pulses in 5 other healthy volunteers. Results: the changes of flow signals in the phantom and in the volunteers were in good accord with those of the signals mathematically predicted and plotted by a computer, as each parameter was varied. the peripheral saturation was weaker at smaller MFA than at larger MFA. A greater profile tilt produced a more pronounced TONE effect than a lower one. the visualization of the peripheral cerebral vessels was markedly improved by the addition of the TONE pulse. Conclusion: Computer simulation is useful for examining the optimal TONE parameters. the TONE pulse markedly improves the visualization of the distal branches of the cerebral vessels.
颈动脉分叉处的 3DFT MR 血管造影：作为筛查检查的潜力和局限性。
影响因子：
19.7
作者：
Masaryk,AM;Ross,JS;DiCello,MC;Modic,MT;Paranandi,L;Masaryk,TJ
通讯作者：
Masaryk,TJ