T2 and T1rho MRI in articular cartilage systems.
T2 and T1rho MRI in articular cartilage systems.
复制标题
DOI：
--
复制
发表时间：
2004
影响因子：
3.3
通讯作者：
N. Menezes;M. Gray;J. Hartke;D. Burstein
中科院分区：
文献类型：
--
作者：
N. Menezes;M. Gray;J. Hartke;D. Burstein
T2 和 T1rho 具有无损检测软骨退化的潜力。然而，文献中关于其诊断解释的报告是相互矛盾的。在本研究中，T2 和 T1rho 在多个系统中在 8.5 T 下测量： 1) 胶原蛋白和 GAG 的分子悬浮液（纯浓度效应）：T2 和 T1rho 表现出随着 [胶原蛋白] 和 [GAG] 的增加呈指数下降，其中 [胶原蛋白] 占主导地位。在 15-20% [胶原蛋白] 范围内，T2 从 90 到 35 ms 变化，T1rho 从 125 到 55 ms 变化，表明水合作用对这些参数的影响可能比之前认识到的更重要。 2) 非定向基质（幼牛软骨）中的大分子：在胶原基质（胰蛋白酶化软骨）中，T2 和 T1rho 值与预期的[胶原]一致，表明基质本身并不主导松弛效应。胶原蛋白/GAG 基质（天然软骨）的 T2 比胶原基质低 13%，T1rho 比胶原基质低 17%，与其较高的大分子浓度一致。复杂基质降解（白细胞介素 1 处理）显示相对于天然组织较低的 T2 和不变的 T1rho，这与浓度和分子水平变化的竞争效应一致。此外，这些样品中的异质 GAG 谱并未反映在 T2 或 T1rho 中。 3) 定向基质（成熟人体组织）中的大分子：定向胶原基质（GAG 耗尽的人体软骨）显示出 T2 和 T(1rho) 随深度的变化，与偏光显微镜下观察到的 16-21% [胶原] 和/或原纤维定向（魔角效应）一致，表明水合和结构都是重要因素。在其他人类软骨区域，观察到 T2 和 T1rho 异常与 GAG 或胶原蛋白方向差异无关，这表明水合和/或分子水平的变化很重要。总体而言，这些研究表明 T2 和 T1rho 对软骨中具有生物学意义的变化敏感。然而，与之前的一些报告相反，它们并不特定于任何一种固有的组织参数。
T2 and T1rho have potential to nondestructively detect cartilage degeneration. However, reports in the literature regarding their diagnostic interpretation are conflicting. In this study, T2 and T1rho were measured at 8.5 T in several systems: 1) Molecular suspensions of collagen and GAG (pure concentration effects): T2 and T1rho demonstrated an exponential decrease with increasing [collagen] and [GAG], with [collagen] dominating. T2 varied from 90 to 35 ms and T1rho from 125 to 55 ms in the range of 15-20% [collagen], indicating that hydration may be a more important contributor to these parameters than previously appreciated. 2) Macromolecules in an unoriented matrix (young bovine cartilage): In collagen matrices (trypsinized cartilage) T2 and T1rho values were consistent with the expected [collagen], suggesting that the matrix per se does not dominate relaxation effects. Collagen/GAG matrices (native cartilage) had 13% lower T2 and 17% lower T1rho than collagen matrices, consistent with their higher macromolecular concentration. Complex matrix degradation (interleukin-1 treatment) showed lower T2 and unchanged T1rho relative to native tissue, consistent with competing effects of concentration and molecular-level changes. In addition, the heterogeneous GAG profile in these samples was not reflected in T2 or T1rho. 3) Macromolecules in an oriented matrix (mature human tissue): An oriented collagen matrix (GAG-depleted human cartilage) showed T2 and T(1rho) variation with depth consistent with 16-21% [collagen] and/or fibril orientation (magic angle effects) seen on polarized light microscopy, suggesting that both hydration and structure comprise important factors. In other human cartilage regions, T2 and T1rho abnormalities were observed unrelated to GAG or collagen orientation differences, demonstrating that hydration and/or molecular-level changes are important. Overall, these studies illustrate that T2 and T1rho are sensitive to biologically meaningful changes in cartilage. However, contrary to some previous reports, they are not specific to any one inherent tissue parameter.