Cerebral multifrequency MR elastography by remote excitation of intracranial shear waves.
Cerebral multifrequency MR elastography by remote excitation of intracranial shear waves.
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DOI：
10.1002/nbm.3388
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发表时间：
2015-11
影响因子：
2.9
通讯作者：
Sack I
中科院分区：
文献类型：
--
作者：
Fehlner A;Papazoglou S;McGarry MD;Paulsen KD;Guo J;Streitberger KJ;Hirsch S;Braun J;Sack I
本研究的目的是引入远程波激励的高分辨率脑多频MR弹性成像（mMRE）。在12名健康志愿者中，将头部摇杆刺激的25-45-Hz驱动频率的mMRE与基于胸垫的远程波激发的mMRE进行比较。星等图|G*| 采用多频双弹粘（MDEV）反演方法重建了复剪切模量的相位φ和相位φ。扫描后，受试者和三名操作员使用两种刺激大脑的方法评估大脑mMRE的舒适性和便利性。在冠状位采集图像，以识别沿脊髓丘脑通路的沿着解剖区域。在通过远程驱动的mMRE中，所有受试者和操作者都赞赏增加的舒适度和简化的程序设置。大脑中产生的应变幅度足够大，可以使用MDEV反演进行分析，并产生高分辨率粘弹性图，揭示了大脑机械特性的特定解剖学细节：|G*| 在皮质脊髓束内，从大脑半球（1.64 ± 0.26 kPa）至内囊（1.29 ± 0.14 kPa）呈下降趋势。通过避免对头部的繁重的机械刺激，可以使用颅内剪切波的远程激励来以高空间分辨率测量大脑的粘弹性参数。因此，新的mMRE方法适用于临床神经放射学检查。
The aim of this study was to introduce remote wave excitation for high-resolution cerebral multifrequency MR elastography (mMRE). mMRE of 25–45-Hz drive frequencies by head rocker stimulation was compared with mMRE by remote wave excitation based on a thorax mat in 12 healthy volunteers. Maps of the magnitude |G*| and phase φ of the complex shear modulus were reconstructed using multifrequency dual elasto-visco (MDEV) inversion. After the scan, the subjects and three operators assessed the comfort and convenience of cerebral mMRE using two methods of stimulating the brain. Images were acquired in a coronal view in order to identify anatomical regions along the spinothalamic pathway. In mMRE by remote actuation, all subjects and operators appreciated an increased comfort and simplified procedural set-up. The resulting strain amplitudes in the brain were sufficiently large to analyze using MDEV inversion, and yielded high-resolution viscoelasticity maps which revealed specific anatomical details of brain mechanical properties: |G*| was lowest in the pons (0.97 ± 0.08 kPa) and decreased within the corticospinal tract in the caudal–cranial direction from the crus cerebri (1.64 ± 0.26 kPa) to the capsula interna (1.29 ± 0.14 kPa). By avoiding onerous mechanical stimulation of the head, remote excitation of intracranial shear waves can be used to measure viscoelastic parameters of the brain with high spatial resolution. Therewith, the new mMRE method is suitable for neuroradiological examinations in the clinic.