Yin Ziying
Department of Bioengineering, University of Illinois at Chicago, Department of Bioengineering (MC 563), Clinical Sciences North (CSN) W103, 820 S Wood St., Chicago, IL, 60612 USA.
Crit Rev Biomed Eng. 2014;42(2):137-91. doi: 10.1615/critrevbiomedeng.2014011843.
The primary goal of this paper is to describe a combined MR relaxation (T(2) and T(1ρ)), diffusion (apparent diffusion coefficient [ADC]), and elastography (shear stiffness) method of fully characterizing the development of tissue-engineered cartilage in terms of the changes in its composition, structure, and mechanical properties during tissue growth. Then, we may better use MR-based methodologies to noninvasively monitor and optimize the cartilage tissue engineering process without sacrificing the constructs. This process begins by demonstrating the potential capability of T(2), T(1ρ), ADC, and shear stiffness in characterizing a scaffold-free engineered cartilage. The results show that, in addition to the conventional T(2) and ADC, T(1ρ) and MRE can be used as potential biomarkers to assess the specific changes in proteoglycan content and mechanical properties of engineered cartilage during culture. Moreover, to increase the efficiency of MR characterization, two new methodologies for simultaneous acquisition of diffusion and MRE (dMRE), and T(1ρ) and MRE (T(1ρ)-MRE) are introduced that allow the simultaneous characterization of both biochemical and mechanical properties of engineered cartilage tissue. The feasibilities of dMRE and T(1ρ)-MRE approaches are validated on tissue-mimicking phantoms. The results show good correspondence between simultaneous acquisitions and conventional separate acquisition methods.
本文的主要目标是描述一种结合磁共振弛豫（T(2)和T(1ρ)）、扩散（表观扩散系数[ADC]）和弹性成像（剪切刚度）的方法，以便根据组织生长过程中组织工程软骨的组成、结构和力学性能变化，全面表征其发育情况。这样，我们就能更好地利用基于磁共振的方法，在不牺牲构建物的前提下，对软骨组织工程过程进行无创监测和优化。这个过程首先要展示T(2)、T(1ρ)、ADC和剪切刚度在表征无支架工程软骨方面的潜在能力。结果表明，除了传统的T(2)和ADC外，T(1ρ)和磁共振弹性成像（MRE）可作为潜在的生物标志物，用于评估培养过程中工程软骨蛋白聚糖含量和力学性能的具体变化。此外，为提高磁共振表征的效率，还引入了两种同时采集扩散和MRE（dMRE）以及T(1ρ)和MRE（T(1ρ)-MRE）的新方法，这两种方法能够同时表征工程软骨组织的生化和力学性能。dMRE和T(1ρ)-MRE方法的可行性在仿组织体模上得到了验证。结果表明，同时采集与传统的单独采集方法之间具有良好的一致性。
