Zheng Shaokuan, Xia Yang
Department of Physics and Center for Biomedical Research, Oakland University, Rochester, Michigan 48309, USA.
Magn Reson Med. 2010 Jan;63(1):25-32. doi: 10.1002/mrm.22169.
The relaxivities (R-values) of the gadolinium diethylene triamine pentaacetic acid (Gd(DTPA)2-) ions in a series of skim-milk solutions at 0-40% milk concentrations were measured using NMR spectroscopy. The R-value was found to be approximately linearly proportional to the concentration of the solid component in the milk solution. Using the R-value at 20% solid component (approximately the solid concentration in bovine nasal cartilage), the glycosaminoglycan concentration in bovine nasal cartilage can be quantified using the MRI delayed gadolinium-enhanced MRI of cartilage method without the customary scaling factor of 2. This finding is also supported by the measurements using 23Na NMR spectroscopy, 23Na inductively coupled plasma analysis, and biochemical assay. The choice of the R-value definition in the MRI delayed gadolinium-enhanced MRI of cartilage method is discussed, and the definition of Gd(DTPA)2- ions as "millimole per volume of tissue (or milk solution for substitution)" should be used.
使用核磁共振光谱法测量了一系列脱脂乳溶液（牛奶浓度为0 - 40%）中钆二乙烯三胺五乙酸（Gd(DTPA)²⁻）离子的弛豫率（R值）。发现R值与乳溶液中固体成分的浓度大致呈线性比例关系。利用20%固体成分时的R值（近似于牛鼻软骨中的固体浓度），可以使用软骨MRI延迟钆增强MRI方法对牛鼻软骨中的糖胺聚糖浓度进行定量，而无需使用常规的2倍缩放因子。使用²³Na核磁共振光谱法、²³Na电感耦合等离子体分析和生化分析进行的测量也支持了这一发现。讨论了软骨MRI延迟钆增强MRI方法中R值定义的选择，应使用将Gd(DTPA)²⁻离子定义为“每单位体积组织（或用于替代的乳溶液）毫摩尔数”的定义。
