Cationic agent contrast-enhanced computed tomography imaging of cartilage correlates with the compressive modulus and coefficient of friction
Cationic agent contrast-enhanced computed tomography imaging of cartilage correlates with the compressive modulus and coefficient of friction
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DOI：
10.1016/j.joca.2012.09.007
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发表时间：
2013-01-01
影响因子：
7
通讯作者：
Snyder, B. D.
中科院分区：
文献类型：
--
作者：
Lakin, B. A.;Grasso, D. J.;Snyder, B. D.
目的：探讨阳离子造影剂(Ca4+)增强CT(CECT)衰减与体外培养牛关节软骨平衡压缩模数(E)和摩擦系数(Mu)的相关性。方法：取6头新鲜屠宰的骨骼成熟奶牛，用直径7 mm的牛骨软骨塞，测定CECT衰减与E(组1，n=12)和Mu(组2，n=10)的相关性。通过四步无侧限压缩应力松弛试验测量了平衡压缩模数，并通过扭转摩擦试验确定了摩擦系数。结果：牛软骨CECT衰减与GAG含量呈正相关(第1组R2=0.87，P<0.0001；第2组R2=0.74，P=0.001)。E与GAG含量呈显著正相关(R2=0.9，P<；0.0001)，CECT衰减率与E呈显著正相关(R-2=0.9，P<；0.0001)。CECT衰减与静摩擦系数呈负相关(R2=0.71，P=0.002)，与静平衡摩擦系数呈负相关(R2=0.79，P&t；0.001)，与摩擦系数呈负相关(R2=0.69，P=0.003)。结论：含Ca~(4+)的CECT是测定软骨组织力学性能的有效工具。(C)2012年国际骨性关节炎研究会。爱思唯尔有限公司出版。保留所有权利。
Objective: The aim of this study is to evaluate whether contrast-enhanced computed tomography (CECT) attenuation, using a cationic contrast agent (CA4+), correlates with the equilibrium compressive modulus (E) and coefficient of friction (mu) of ex vivo bovine articular cartilage.Methods: Correlations between CECT attenuation and E (Group 1, n = 12) and mu (Group 2, n = 10) were determined using 7 mm diameter bovine osteochondral plugs from the stifle joints of six freshly slaughtered, skeletally mature cows. The equilibrium compressive modulus was measured using a four-step, unconfined, compressive stress-relaxation test, and the coefficients of friction were determined from a torsional friction test. Following mechanical testing, samples were immersed in CA4+, imaged using mu CT, rinsed, and analyzed for glycosaminoglycan (GAG) content using the 1,9-dimethylmethylene blue (DMMB) assay.Results: The CECT attenuation was positively correlated with the GAG content of bovine cartilage (R-2 = 0.87, P < 0.0001 for Group 1 and R-2 = 0.74, P = 0.001 for Group 2). Strong and significant positive correlations were observed between E and GAG content (R-2 = 0.90, P < 0.0001) as well as CECT attenuation and E (R-2 = 0.90, P < 0.0001). The CECT attenuation was negatively correlated with the three coefficients of friction: CECT vs mu(static) (R-2 = 0.71, P = 0.002), CECT vs mu(static_equilibrium) (R-2 = 0.79, P < 0.001), and CECT vs mu(kinetic) (R-2 = 0.69, P = 0.003).Conclusions: CECT with CA4+ is a useful tool for determining the mechanical properties of ex vivo cartilage tissue as the attenuation significantly correlates with the compressive modulus and coefficient of friction. (C) 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.