Ling Wen, Regatte Ravinder R, Schweitzer Mark E, Jerschow Alexej
Chemistry Department, New York University, New York, New York, USA.
Magn Reson Med. 2006 Nov;56(5):1151-5. doi: 10.1002/mrm.21062.
The onset of cartilage tissue disorders can be characterized by a loss of proteoglycans (PGs) and diagnosed by contrast-enhanced proton ((1)H) MRI techniques, as well as sodium MRI. The behavior of sodium located in anisotropic environments, is examined as a function of cartilage degeneration. PGs are proteolytically depleted from the cartilage samples, which gives rise to a decrease of the ordered sodium content. More surprisingly, however, the residual quadrupolar couplings are shown to increase with increasing depletion levels. Since the residual quadrupolar couplings are intimately related to local order and anisotropic motion, measuring their distribution in cartilage may provide insight into the structural changes that occur within the tissue upon degradation. In this study relatively mild orientational dependence of the couplings was found. Little or no free sodium was observed in the cartilage specimens under study.
软骨组织疾病的发作可表现为蛋白聚糖（PGs）的流失，并可通过对比增强质子（(1)H）MRI技术以及钠MRI进行诊断。研究了处于各向异性环境中的钠的行为与软骨退变的关系。PGs从软骨样本中被蛋白水解消耗，这导致有序钠含量降低。然而，更令人惊讶的是，残余四极耦合显示随着消耗水平的增加而增加。由于残余四极耦合与局部有序性和各向异性运动密切相关，测量它们在软骨中的分布可能有助于深入了解组织退变时发生的结构变化。在本研究中，发现耦合具有相对较弱的取向依赖性。在所研究的软骨标本中几乎没有观察到游离钠。
