Klatt Dieter, Johnson Curtis L, Magin Richard L
The Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA.
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
J Magn Reson Imaging. 2015 Aug;42(2):297-304. doi: 10.1002/jmri.24806. Epub 2014 Nov 26.
To implement a multidirectional motion encoding scheme for magnetic resonance elastography (MRE) of the human brain with reduced acquisition time, and investigate its performance relative to a conventional MRE scheme.
The sample interval modulation (SLIM) scheme was implemented in a multishot, variable density spiral MRE sequence. The brains of seven healthy volunteers were investigated with both SLIM-MRE and conventional MRE acquisitions in a single imaging session on a clinical 3 Tesla MRI scanner with 50 Hz vibration. Following extraction of displacement fields, complex shear modulus property maps were estimated for each encoding concept.
The SLIM-MRE and conventional MRE acquisitions produced deformation fields that were nearly identical and exhibited an average correlation coefficient of 0.95 (all p < 0.05). Average properties of white matter differed between the two acquisitions by less than 5% for all volunteers, which is better than reproducibility estimates for conventional MRE alone.
The use of SLIM provides very similar quantitative property estimates compared with the conventional MRE encoding scheme. The SLIM acquisition is 2.5 times faster than the conventional acquisition, and may speed the adoption of MRE in clinical settings.
为减少采集时间，实现用于人脑磁共振弹性成像（MRE）的多向运动编码方案，并研究其相对于传统MRE方案的性能。
在多激发、可变密度螺旋MRE序列中实施样本间隔调制（SLIM）方案。在配备50 Hz振动的临床3特斯拉MRI扫描仪上，在一次成像检查中，对7名健康志愿者的大脑进行了SLIM-MRE和传统MRE采集。提取位移场后，针对每个编码概念估计复剪切模量特性图。
SLIM-MRE和传统MRE采集产生的变形场几乎相同，平均相关系数为0.95（所有p<0.05）。所有志愿者的两次采集中白质的平均特性差异小于5%，这优于仅传统MRE的再现性估计。
与传统MRE编码方案相比，SLIM的使用提供了非常相似的定量特性估计。SLIM采集速度比传统采集快2.5倍，可能会加快MRE在临床环境中的应用。
