Dhenain Marc, Delatour Benoît, Walczak Christine, Volk Andreas
Integrative Imaging Unit, Curie Institute-INSERM, Centre Universitaire. Laboratoire 112, France.
Magn Reson Med. 2006 Mar;55(3):687-93. doi: 10.1002/mrm.20810.
Amyloid plaques are one of the hallmarks of Alzheimer's disease (AD). This study evaluated a novel microMRI strategy based on "passive staining" of brain samples by gadoteric acid. The protocol was tested at 4.7 T on control animals and APP/PS1 mice modeling AD lesions. T(1) was strongly decreased in passively stained brains. On high-resolution 3D gradient echo images, the contrast between the cortex and subcortical structures was highly improved due to a T2* effect. The brains of APP/PS1 mice revealed plaques as hypo-intense spots. They appeared larger in long compared to short TE images. This suggests that, after passive staining, plaques caused a susceptibility effect. This easily performed protocol is a complementary method to classic histology to detect the 3D location of plaques. It may also be used for the validation of in vivo MRI protocols for plaque detection by facilitating registration with histology via post mortem MRI.
淀粉样斑块是阿尔茨海默病（AD）的标志性特征之一。本研究评估了一种基于钆特酸对脑样本进行“被动染色”的新型显微磁共振成像（microMRI）策略。该方案在4.7 T条件下对对照动物和模拟AD损伤的APP/PS1小鼠进行了测试。被动染色的大脑中T(1)显著降低。在高分辨率三维梯度回波图像上，由于T2*效应，皮质与皮质下结构之间的对比度得到了显著改善。APP/PS1小鼠的大脑中，斑块表现为低信号斑点。与短回波时间（TE）图像相比，在长TE图像中它们显得更大。这表明，被动染色后，斑块产生了磁化率效应。这种易于实施的方案是一种用于检测斑块三维位置的经典组织学的补充方法。它还可通过尸检MRI促进与组织学的配准，用于体内MRI斑块检测方案的验证。
