GRadient echo Acquisition for Superparamagnetic particles with positive contrast (GRASP): Sequence characterization in membrane and glass superparamagnetic iron oxide phantoms at 1.5T and 3T
GRadient echo Acquisition for Superparamagnetic particles with positive contrast (GRASP): Sequence characterization in membrane and glass superparamagnetic iron oxide phantoms at 1.5T and 3T
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DOI：
10.1002/mrm.20739
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发表时间：
2006-01-01
影响因子：
3.3
通讯作者：
Fayad, ZA
中科院分区：
文献类型：
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作者：
Mani, V;Briley-Saebo, KC;Fayad, ZA
氧化铁用于细胞运输和使用MRI识别斑块中的巨噬细胞。由于负对比度，区分由铁引起的信号损失和组织中的天然低信号可能是有问题的。因此，优选实现正对比度。本研究的目的是测试一种新的MRI序列GRASP（超顺磁性颗粒的GRe采集）在含铁体模中产生阳性信号的有效性。构建了含有7种浓度Ferumoxide的膜模型。使用用户控制的z梯度重定相（+/- 100%）修改标准GRE序列。CNR值被确定为回波时间（TE）和1.5T和3 T下的%重新定相的函数。使用多重双回波GRE确定T-2（星星）值。GRASP序列在含铁的体模中产生阳性信号增强。对于所有重定相值
Iron oxides are used for cell trafficking and identification of macrophages in plaque using MRI. Due to the negative contrast, differentiation between signal loss caused by iron and native low signal in tissue may be problematic. It is, therefore, preferable to achieve positive contrast. The purpose of this study was to test the efficacy of a new MRI sequence GRASP (GRe Acquisition for Superparamagnetic Particles) to generate a positive signal in phantoms containing iron. Membrane phantoms were constructed containing Ferumoxide at 7 concentrations. Standard GRE sequences were modified with user controlled z-gradient rephasing (+/- 100%). CNR values were determined as a function of echo time (TE) and % rephasing at 1.5T and 3T. T-2(star) values were determined using multiple double-echo GRE. The GRASP sequence generated positive signal enhancement in phantoms containing iron. For all rephasing values