Sensitive and automated detection of iron-oxide-labeled cells using phase image cross-correlation analysis
Sensitive and automated detection of iron-oxide-labeled cells using phase image cross-correlation analysis
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DOI：
10.1016/j.mri.2008.01.007
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发表时间：
2008-06-01
影响因子：
2.5
通讯作者：
Ahrens, Eric T.
中科院分区：
文献类型：
--
作者：
Mills, Parker H.;Wu, Yi-Jen L.;Ahrens, Eric T.
超顺磁性氧化铁(SPIO)纳米粒子越来越多地被用于非侵入性追踪细胞、靶向特定分子和监测体内基因表达。相对于内在对比度来源而言，微妙的对比度变化是一个重大的检测挑战。在这里，我们描述了一个后处理算法，称为相位图互相关检测和量化(PDQ)，目的是自动识别和量化SPIO试剂的局部积累。该方法的设计牺牲了很小的灵活性-它处理以前采集的数据，并允许使用传统的高信噪比脉冲序列，而不需要额外的扫描时间。我们首先利用模拟的偶极场研究了PDQ的理论探测极限。然后将该方法应用于含有分离偶极的琼脂糖凝胶和由于器官排斥反应而被大量氧化铁标记的巨噬细胞渗透的体外移植大鼠心脏的三维(3D)MRI数据集。一个模拟的偶极子场表明，该方法在非常低信噪比的图像中具有很好的鲁棒性。对琼脂糖凝胶和同种异体大鼠心脏的分析表明，该方法可以自动识别和计数偶极子，同时在3D渲染中可视化它们的生物分布。在心脏，这些信息被用来计算一个量化指数，该指数可能表明心脏的细胞渗透程度。(C)2008 Elsevier Inc.保留所有权利。
Super-paramagnetic iron oxide (SPIO) narroparticles are increasingly being used to noninvasively track cells, target specific molecules and monitor gene expression in vivo. Contrast changes that are subtle relative to intrinsic sources of contrast present a significant detection challenge. Here, we describe a postprocessing algorithm, called Phase map cross-correlation Detection and Quantification (PDQ), with the purpose of automating identification and quantification of localized accumulations of SPIO agents. The method is designed to sacrifice little flexibility - it works on previously acquired data and allows the use of conventional high-SNR pulse sequences with no extra scan time. We first investigated the theoretical detection limits of PDQ using a simulated dipole field. This method was then applied to three-dimensional (3D) MRI data sets of agarose gel containing isolated dipoles and ex vivo transplanted allogenic rat hearts infiltrated by numerous iron-oxide-labeled macrophages as a result of organ rejection. A simulated dipole field showed this method to be robust in very low signal-to-noise ratio images. Analysis of agarose gel and allogenic rat heart shows that this method can automatically identify and count dipoles while visualizing their biodistribution in 3D renderings. In the heart, this information was used to calculate a quantitative index that may indicate its degree of cellular infiltration. (C) 2008 Elsevier Inc. All rights reserved.