Relaxation effects of clustered particles
Relaxation effects of clustered particles
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DOI：
10.1002/jmri.1153
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发表时间：
2001-07-01
影响因子：
4.4
通讯作者：
Stark, DD
中科院分区：
文献类型：
--
作者：
Tanimoto, A;Oshio, K;Stark, DD
研究了超顺磁性氧化铁（SPIO）粒子的空间分布与其引起的图像对比度之间的关系。使用活体激光共聚焦显微镜在动物的肝脏和脾脏中测量颗粒的实际聚集模式。SPIO掺杂phantomy与和没有葡聚糖凝胶珠模拟这些模式，和松弛参数测量使用1.5 T的临床扫描仪。最后，将这些结果与使用SPIO颗粒剂的临床图像数据进行比较。活体显微镜观察发现，肝枯否细胞内的乳胶珠聚集明显多于脾巨噬细胞（P < 0.001）。不含Sephadex珠的葡聚糖凝胶显示随着SPIO浓度的增加，1/T1（R1）、1/T2（R2）和1/T2*（R2*）值近似线性增加。然而，在Sephadex珠的情况下，RI和R2随着SPIO浓度的增加而几乎没有变化，而R2* 随着SPIO浓度的增加而显示出相同的线性增加。此外，R2* 值较高的Sephadex珠。这些结果与临床影像学数据一致，其中脾脏中的信号降低明显较小（-0.4% +/- 27.4%），高于肝脏（50.4% +/-16.8%，P < 0.00001）T2* 加权图像，但在T2加权图像上，脾脏（47.2% ± 16.1%）的减少与肝脏（38.8% ± 26.0%）相当。(C)2001 Wiley-Liss，Inc.
Relations between spatial distribution of superparamagnetic iron oxide (SPIO) particles and the image contrast caused by SPIO were investigated. Actual clustering pattern of particles was measured in the liver and spleen of animals using intravital laser confocal microscopy. SPIO-doped phantoms with and without Sephadex beads were made to simulate these patterns, and relaxation parameters were measured using a 1.5-T clinical scanner. Finally, these results were compared to clinical image data using SPIO particulate agent. Intravital microscopy indicated that the clustering of latex beads was more predominant in hepatic Kupffer cells than in splenic macrophages (P < 0.001). Phantoms without Sephadex beads showed an approximately linear increase of 1/T1 (R1), 1/T2 (R2) and 1/T2* (R2*) values with increasing SPIO concentration. However, with Sephadex beads, RI and R2 showed little change with increasing SPIO concentration, while R2* showed the same linear increase with SPIO. Also, the R2* values were higher with Sephadex beads. These results were consistent with the clinical imaging data, where signal reduction was significantly smaller in the spleen (-0.4% +/- 27.4%) than in the liver (50.4% +/- 16.8%, P < 0.00001) on T2*-weighted images, but the reduction in the spleen (47.2% +/- 16.1%) was equivalent to the liver (38.8% +/- 26.0%) on T2-weighted images. (C) 2001 Wiley-Liss, Inc.