POsitive contrast magnetic resonance imaging of cells labeled with magnetic nanoparticles
POsitive contrast magnetic resonance imaging of cells labeled with magnetic nanoparticles
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DOI：
10.1002/mrm.20477
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发表时间：
2005-05-01
影响因子：
3.3
通讯作者：
Conolly, SM
中科院分区：
文献类型：
--
作者：
Cunningham, CH;Arai, T;Conolly, SM
含有超顺磁性氧化铁纳米颗粒的造影剂已显示出有望作为一种利用磁共振成像（MRI）可视化标记细胞的手段。由于在细胞附近的水分子中诱导出的磁场不均匀性，标记细胞会导致显著的信号失相。以产生的信号缺失作为检测手段，这些颗粒表现为一种阴性造影剂，可能会受到部分容积效应的影响。在本文中，描述了一种对标记细胞进行正性造影成像的新方法。频谱选择性射频脉冲被用于激发和重聚焦标记细胞周围的非共振水，使得只有紧邻标记细胞的液体和组织在图像中可见。体模、体外和体内实验表明了这种新方法的可行性。在估计的细胞数量和信号之间观察到了显著的线性相关性（r = 0.87，P < 0.005）。（c）2005威利 - 利斯公司
Contrast agents incorporating superparamagnetic iron-oxide nanoparticles have shown promise as a means to visualize labeled cells using MRI. Labeled cells cause significant signal dephasing due to the magnetic field inhomogeneity induced in water molecules near the cell. With the resulting signal void as the means for detection, the particles behave as a negative contrast agent, which can suffer from partial-volume effects. In this paper, a new method is described for imaging labeled cells with positive contrast. Spectrally selective RF pulses are used to excite and refocus the off-resonance water surrounding the labeled cells so that only the fluid and tissue immediately adjacent to the labeled cells are visible in the image. Phantom, in vitro, and in vivo experiments show the feasibility of the new method. A significant linear correlation (r = 0.87, P < 0.005) between the estimated number of cells and the signal was observed. (c) 2005 Wiley-Liss, Inc.