Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
J Magn Reson Imaging. 2011 Sep;34(3):494-8. doi: 10.1002/jmri.22707. Epub 2011 Jul 12.
To test patient acceptance and reproducibility of the 3D magnetic resonance elastography (MRE) brain exam using a soft vibration source, and to determine if MRE could noninvasively measure a change in the elastic properties of the brain parenchyma due to Alzheimer's disease (AD).
MRE exams were performed using an accelerated spin-echo echo planar imaging (EPI) pulse sequence and stiffness was calculated with a 3D direct inversion algorithm. Reproducibility of the technique was assessed in 10 male volunteers, who each underwent four MRE exams separated into two imaging sessions. The effect of AD on brain stiffness was assessed in 28 volunteers, 7 with probable AD, 14 age- and gender-matched PIB-negative (Pittsburgh Compound B, a PET amyloid imaging ligand) cognitively normal controls (CN-), and 7 age- and gender-matched PIB-positive cognitively normal controls (CN+).
The median stiffness of the 10 volunteers was 3.07 kPa with a range of 0.40 kPa. The median and maximum coefficients of variation for these volunteers were 1.71% and 3.07%. The median stiffness of the 14 CN- subjects was 2.37 kPa (0.44 kPa range) compared to 2.32 kPa (0.49 kPa range) within the CN+ group and 2.20 kPa (0.33 kPa range) within the AD group. A significant difference was found between the three groups (P = 0.0055, Kruskal-Wallis one-way analysis of variance). Both the CN+ and CN- groups were significantly different from the AD group.
3D MRE of the brain can be performed reproducibly and demonstrates significantly reduced brain tissue stiffness in patients with AD.
使用软振动源测试 3D 磁共振弹性成像 (MRE) 脑部检查的患者接受度和可重复性，并确定 MRE 是否可以无创测量由于阿尔茨海默病 (AD) 而导致的脑实质弹性特性的变化。
使用加速自旋回波回波平面成像 (EPI) 脉冲序列进行 MRE 检查，并使用 3D 直接反转算法计算刚度。在 10 名男性志愿者中评估了该技术的可重复性，每位志愿者在两次成像过程中进行了四次 MRE 检查。在 28 名志愿者中评估了 AD 对脑硬度的影响，其中 7 名患有可能的 AD，14 名年龄和性别匹配的 PIB-阴性（匹兹堡化合物 B，一种 PET 淀粉样蛋白成像配体）认知正常对照 (CN-)，和 7 名年龄和性别匹配的 PIB-阳性认知正常对照 (CN+)。
10 名志愿者的中位数刚度为 3.07 kPa，范围为 0.40 kPa。这些志愿者的中位数和最大变异系数分别为 1.71%和 3.07%。14 名 CN- 受试者的中位数刚度为 2.37 kPa（范围为 0.44 kPa），而 CN+ 组的中位数刚度为 2.32 kPa（范围为 0.49 kPa），AD 组的中位数刚度为 2.20 kPa（范围为 0.33 kPa）。三组之间存在显著差异（P = 0.0055，Kruskal-Wallis 单向方差分析）。CN+和 CN- 组与 AD 组均有显著差异。
脑的 3D MRE 可以重复进行，并显示出 AD 患者的脑组织刚度明显降低。
