Department of Radiology, Tokyo Women's Medical University Medical Center East, Tokyo, Japan.
J Magn Reson Imaging. 2011 Feb;33(2):432-40. doi: 10.1002/jmri.22465.
To elucidate the causes of aliasing artifacts with the BLADE technique and clarify the effective suppression methods.
We separately observed the aliasing artifacts of BLADE from features inside and then outside the defined field-of-view (FOV) using phantom studies. The effectiveness of suppressing them with phase oversampling (POS) and presaturation pulses (SAT) was evaluated. Finally, our observations were confirmed for a healthy volunteer.
Characteristic aliasing artifacts were observed from both inside and outside the FOV. Those from inside the FOV were sufficiently suppressed by using a POS of 25%, considering the acquisition time prolongation. Those from outside the FOV were nearly suppressed using SAT outside the FOV without selecting needless receiver coils. Aliasing artifacts on the coronal images of the head and neck with a healthy volunteer were completely suppressed by a combination of using a POS of 25% and using SAT on all four sides outside the FOV.
The characteristic aliasing artifacts of BLADE are caused from both inside and outside the defined FOV. They can be effectively suppressed by a combination of using a POS of 25% and using SAT on all four sides outside the FOV.
阐明 BLADE 技术中出现的混叠伪影的原因,并阐明有效的抑制方法。
我们通过体模研究分别观察了在定义的视野(FOV)内外使用 BLADE 时的混叠伪影。评估了相位过采样(POS)和预饱和脉冲(SAT)抑制它们的有效性。最后,我们对一名健康志愿者进行了观察。
在 FOV 内外都观察到了特征性的混叠伪影。在考虑到采集时间延长的情况下,使用 25%的 POS 可以充分抑制 FOV 内的混叠伪影。在不选择不必要的接收线圈的情况下,在 FOV 外使用 SAT 可以几乎抑制 FOV 外的混叠伪影。使用 25%的 POS 和在 FOV 外的所有四个侧面使用 SAT 的组合可以完全抑制健康志愿者的头部和颈部冠状图像上的混叠伪影。
BLADE 的特征性混叠伪影是由 FOV 内外共同引起的。通过使用 25%的 POS 和在 FOV 外的所有四个侧面使用 SAT 的组合可以有效地抑制它们。