Simultaneous fat suppression and band reduction with large-angle multiple-acquisition balanced steady-state free precession.
Simultaneous fat suppression and band reduction with large-angle multiple-acquisition balanced steady-state free precession.
复制标题
DOI：
10.1002/mrm.23076
复制
发表时间：
2012-04
影响因子：
3.3
通讯作者：
Bangerter, Neal K.
中科院分区：
文献类型：
--
作者：
Quist, Brady;Hargreaves, Brian A.;Cukur, Tolga;Morrell, Glen R.;Gold, Garry E.;Bangerter, Neal K.
平衡稳态自由旋进（bSSFP）MRI是一种快速且SNR有效的成像方法，但是在大的场不均匀性的区域中遭受信号损失的特征频带。已经开发了几种方法来降低这些条带伪影的严重性，通常涉及多个bSSFP数据集的采集（以及伴随的扫描时间增加）。使用bSSFP进行脂肪抑制也具有挑战性;大多数现有方法需要额外增加扫描时间，并且一些方法与bSSFP频带缩减技术不兼容。这项工作的动机是，当使用bSSFP进行非血流依赖性外周血管造影时，需要在存在场不均匀性的情况下进行稳健的脂肪抑制和频带减少。本应用中用于改善血管显著性和对比度的大翻转角导致SAR考虑、TR延长和条带伪影严重程度增加。在这项工作中，提出了一种新的方法，同时抑制脂肪和减少bSSFP带伪影的收购只有两个相位循环的bSSFP数据集。两个bSSFP采集的加权和是在逐体素的基础上进行的，有效地合成了每个体素处的非共振轮廓，将脂肪置于阻带中，同时将水保持在通带中。该技术在大（>50度）翻转角下针对许多组织利用bSSFP非共振谱的近正弦形状。
Balanced steady-state free precession (bSSFP) MRI is a rapid and SNR-efficient imaging method, but suffers from characteristic bands of signal loss in regions of large field inhomogeneity. Several methods have been developed to reduce the severity of these banding artifacts, typically involving the acquisition of multiple bSSFP data sets (and the accompanying increase in scan time). Fat suppression with bSSFP is also challenging; most existing methods require an additional increase in scan time, and some are incompatible with bSSFP band-reduction techniques. This work was motivated by the need for both robust fat suppression and band reduction in the presence of field inhomogeneity when using bSSFP for flow-independent peripheral angiography. The large flip angles used in this application to improve vessel conspicuity and contrast lead to SAR considerations, longer TR, and increased severity of banding artifacts. In this work, a novel method that simultaneously suppresses fat and reduces bSSFP banding artifact with the acquisition of only two phase-cycled bSSFP data sets is presented. A weighted sum of the two bSSFP acquisitions is taken on a voxel-by-voxel basis, effectively synthesizing an off-resonance profile at each voxel that puts fat in the stop band while keeping water in the pass band. The technique exploits the near-sinusoidal shape of the bSSFP off-resonance spectrum for many tissues at large (>50 degrees) flip angles.
登录
查看更多内容
影响因子：
3.3
作者：
Foxall, DL
通讯作者：
Foxall, DL
影响因子：
3.3
作者：
Hennig, J;Speck, O;Scheffler, K
通讯作者：
Scheffler, K
影响因子：
3.3
作者：
Nayak, Krishna S.;Lee, Hsu-Lei;Hu, Bob S.
通讯作者：
Hu, Bob S.
影响因子：
3.3
作者：
Bangerter, NK;Hargreaves, BA;Nishimura, DG
通讯作者：
Nishimura, DG
DOI：
10.1002/jmri.1880070405
发表时间：
1997-07-01
期刊：
JMRI-JOURNAL OF MAGNETIC RESONANCE IMAGING
影响因子：
--
作者：
Gronas, R;Kalman, PG;Wright, GA
通讯作者：
Wright, GA