Ahrens E T, Rothbächer U, Jacobs R E, Fraser S E
Beckman Institute and Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA.
Proc Natl Acad Sci U S A. 1998 Jul 21;95(15):8443-8. doi: 10.1073/pnas.95.15.8443.
Contrast in MRI relies on differences in the local environment of water and is often enhanced by using contrast agents. We present a simple model for evaluating the minimal contrast agent concentration required to produce "satisfactory" contrast enhancement in magnetic resonance images. Previous strategies have been based largely on empirical results for specific systems. The present tissue contrast model (TCM) can be applied to "conventional," targeted, or biochemically responsive agents. The model results are formulated so that only a small number of parameters are required to analyze a given scenario. The TCM is a particularly useful tool in the development of new classes of magnetic resonance contrast media. These agents will have the ability to target specific cells or tissue, and perhaps be able to report on their physiological status. As an example of the applicability of the TCM, we test it against in vivo magnetic resonance microscopy results in frog embryos that have focal cell populations labeled with contrast agent by using calibrated single-cell microinjection techniques.
磁共振成像（MRI）中的对比度依赖于水的局部环境差异，并且通常通过使用造影剂来增强。我们提出了一个简单的模型，用于评估在磁共振图像中产生“满意”对比度增强所需的最小造影剂浓度。以前的策略很大程度上基于特定系统的经验结果。当前的组织对比度模型（TCM）可应用于“传统”、靶向或生化响应性造影剂。该模型结果的制定方式使得分析给定场景仅需要少量参数。TCM是开发新型磁共振造影剂的特别有用的工具。这些造影剂将能够靶向特定细胞或组织，并且或许能够报告它们的生理状态。作为TCM适用性的一个例子，我们通过使用校准的单细胞显微注射技术，将其与对青蛙胚胎进行的体内磁共振显微镜检查结果进行对比测试，这些青蛙胚胎中有局部细胞群体用造影剂标记。
