Proteoglycan depletion-induced changes in transverse relaxation maps of cartilage:: Comparison of T2 and T1ρ
Proteoglycan depletion-induced changes in transverse relaxation maps of cartilage:: Comparison of T2 and T1ρ
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DOI：
10.1016/s1076-6332(03)80666-9
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发表时间：
2002-12-01
影响因子：
4.8
通讯作者：
Reddy, R
中科院分区：
文献类型：
--
作者：
Regatte, RR;Akella, SVS;Reddy, R
理由和目标。作者进行这项研究是为了（a）测量T2弛豫速率、信噪比（SNR）的变化，并与软骨中蛋白聚糖的连续消耗进行对比;（B）确定T2弛豫速率和软骨中蛋白聚糖之间是否存在关系;和（c）比较T2映射方法与旋转坐标系中的自旋-晶格弛豫时间（T1 rho）映射方法在蛋白聚糖定量中的作用。材料与方法。T2和T1 rho加权磁共振（MR）图像获得了5，牛髌骨。所有图像均使用4 T全身MR装置和10 cm直径的发射-接收正交鸟笼线圈（调谐至170 MHz）获得。计算T2和T1 rho图。T2加权图像的信噪比和对比度平均比相应的T1 rho加权图像低约43%。T2弛豫率随机变化，没有任何特定的趋势，这与蛋白聚糖的连续消耗相关性较差（R2 = 0.008，P <0.70）。组织中蛋白多糖含量与T1 rho舒张率呈良好的线性相关（RI = 0.85，P <0.0001）。T2加权成像既不能产生软骨中蛋白多糖分布变化的定量信息，也不能用于纵向研究以量化蛋白多糖诱导的变化。然而，T1 rho加权成像对牛软骨中蛋白多糖的连续消耗敏感，可用于量化蛋白多糖诱导的变化。
Rationale and Objectives. The authors performed this study to (a) measure changes in T2 relaxation rates, signal-to-noise ratio (SNR), and contrast with sequential depletion of proteoglycan in cartilage; (b) determine whether there is a relationship between the T2 relaxation rate and proteoglycan in cartilage; and (c) compare the T2 mapping method with the spin-lattice relaxation time in the rotating frame (T1rho) mapping method in the quantification of proteoglycan-induced changes.Materials and Methods. T2- and T1rho-weighted magnetic resonance (MR) images were obtained in five, bovine patellae. All images were obtained with a 4-T whole-body MR unit and a 10-cm-diameter transmit-receive quadrature birdcage coil tuned to 170 MHz. T2 and T1rho maps were computed.Results. The SNR and contrast on the T2-weighted images were, on average, about 43% lower than those on the corresponding T1rho-weighted images. The T2 relaxation rates varied randomly without any particular trend, which yielded a poor correlation with sequential depletion of proteoglycan (R2 = 0.008, P < .70). There was excellent linear correlation between the percentage of proteoglycan in the tissue and the T1rho relaxation rate (RI = 0.85, P < .0001).Conclusion. T2-weighted imaging neither yields quantitative information about the changes in proteoglycan distribution in cartilage nor can be used for longitudinal studies to quantify proteoglycan-induced changes. T1rho-weighted imaging, however, is sensitive to sequential depletion of proteoglycan in bovine cartilage and can be used to quantify proteoglycan-induced changes.