...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Investigative radiology >NMRD investigation of DyDTPA- and GdDTPA-labeled starch particles. Selection of a suitable suspension medium and influence of the starch matrix on relaxivity.
【24h】

NMRD investigation of DyDTPA- and GdDTPA-labeled starch particles. Selection of a suitable suspension medium and influence of the starch matrix on relaxivity.

机译：DyDTPA和GdDTPA标记的淀粉颗粒的NMRD研究。合适的悬浮介质的选择以及淀粉基质对松弛度的影响。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

RATIONALE AND OBJECTIVES: The primary aim was to investigate the influence of the starch matrix on the T1 relaxivities of starch particles labeled with gadolinium and dysprosium diethylenetriamine pentaacetic acid (GdDTPA-SP and DyDTPA-SP). Achieving this required the selection of a medium that was suitable for suspending the particles and that had field-independent T1 relaxation rates, thereby eliminating errors in relaxivity determinations resulting from a field-dependent background. METHODS: GdDTPA-SP with low and high gadolinium content, DyDTPA-SP, and empty DTPA-SP were suspended in an aqueous medium containing 5% (w/w) of a polyethylene glycol-based block copolymer. 1/T1 NMRD profiles were obtained in the temperature range of 5 degrees to 35 degrees C. RESULTS: Using the block copolymer, particles did not settle, and samples could be prepared at a low temperature to avoid particle degradation, the intrinsic T1 relaxation rate of the suspension medium was field-independent and identical to that of water from 25 degrees to 35 degrees C. The T1 relaxivities of DyDTPA-SP were higher than those of dysprosium diethylenetriamine pentaacetate-bis(methylamide) (DyDTPA-BMA) and decreased with increasing magnetic field strength. The T1 relaxivity of GdDTPA-SP was higher than that of GdDTPA at all fields, and decreased with decreasing temperature and increasing gadolinium content. CONCLUSIONS: The GdDTPA-SP results showed that the particulate starch matrix served a dual role, with opposing influences on relaxivity. It provided a means for increasing the rotational correlation time (tau R), which resulted in higher relaxivities. However, it also retarded radial diffusion of water molecules within the particle interior, which significantly counteracted the enhancing effect of tau R. For DyDTPA-SP, the starch matrix provided an additional diamagnetic contribution, resulting in relaxivities higher than those of DyDTPA-BMA. The block copolymer was suitable as a suspension medium for DyDTPA-SP and GdDTPA-SP and should also be applicable for other particulates.
机译：理由和目的：主要目的是研究淀粉基质对用g和二乙三胺五乙酸（GdDTPA-SP和DyDTPA-SP）标记的淀粉颗粒的T1弛豫性的影响。为此，需要选择一种适合于悬浮颗粒并且具有与电场无关的T1弛豫速率的介质，从而消除由与电场有关的背景导致的弛豫度测定中的误差。方法：将low含量低和高的GdDTPA-SP，DyDTPA-SP和空的DTPA-SP悬浮在含有5％（w / w）聚乙二醇基嵌段共聚物的水性介质中。在5到35摄氏度的温度范围内获得了1 / T1 NMRD谱图。结果：使用嵌段共聚物，粒子没有沉降，可以在低温下制备样品以避免粒子降解，固有的T1弛豫率悬浮介质的电场独立性与25°C至35°C的水相同。DyDTPA-SP的T1弛豫率高于二亚乙基三胺五乙酸acet-双（甲基酰胺）D（DyDTPA-BMA）的T1弛豫率增加磁场强度。 GdDTPA-SP的T1弛豫率在所有领域均高于GdDTPA，但随温度降低和g含量增加而降低。结论：GdDTPA-SP结果表明，淀粉颗粒基质起到双重作用，对松弛度有相反的影响。它提供了增加旋转相关时间（tau R）的方法，这导致了更高的弛豫度。但是，它也阻碍了水分子在颗粒内部的径向扩散，这显着抵消了tau R的增强作用。对于DyDTPA-SP，淀粉基体提供了额外的抗磁作用，从而导致松弛度高于DyDTPA-BMA。嵌段共聚物适合作为DyDTPA-SP和GdDTPA-SP的悬浮介质，也应适用于其他颗粒。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号