Department of Physics, University of Kuopio, P.O. Box 1627, FI-70211, Kuopio, Finland.
Osteoarthritis Cartilage. 2009 Dec;17(12):1583-8. doi: 10.1016/j.joca.2009.06.010. Epub 2009 Jul 8.
Contrast agent enhanced computed tomography (CECT) may be used to detect depletion of superficial proteoglycans in articular cartilage. In principle, computed tomography can also be used to diagnose the state of subchondral bone. Because osteoarthritis affects both cartilage and bone, we aimed to evaluate the feasibility of the CECT to simultaneously assess the state of these tissues. Further, we studied the spatial variation of contrast agent content in the CECT, properties of subchondral bone and the mechanical stiffness of articular cartilage across the bovine medial tibial plateau.
Osteochondral samples (n=10) were prepared from fresh and visually intact bovine medial tibial plateaus. The dynamic mechanical modulus of the samples was measured using an arthroscopic indentation device. Subsequently, the samples were scanned with a peripheral quantitative computed tomography (pQCT) device prior to and after 35.5h of immersion in an anionic iodinated contrast agent, (ioxaglate) solution. The thickness of the cartilage was measured with ultrasound and pQCT.
In the medial tibial plateau, the site-dependent variation in the dynamic modulus, thickness of the cartilage, thickness of the subchondral plate and contrast agent content in the superficial cartilage was statistically significant (P<0.01). The linear correlation between the superficial contrast agent content and the dynamic modulus was rho=-0.80 (P<0.01).
The CECT enabled simultaneous analysis of the contrast agent penetration into cartilage, cartilage thickness and subchondral bone density and thickness. The contrast agent content in cartilage depends on the composition and structure of the tissue. Thereby the CECT also provided indirect information on the mechanical properties of the tissue, analogously to the dGEMRIC. Thus, the CECT may provide means to diagnose simultaneously the integrity of cartilage and subchondral bone in vivo.
对比增强计算机断层扫描（CECT）可用于检测关节软骨表面蛋白聚糖的耗竭。原则上，计算机断层扫描也可用于诊断骨软骨下骨的状态。由于骨关节炎同时影响软骨和骨骼，我们旨在评估 CECT 同时评估这些组织状态的可行性。此外，我们研究了 CECT 中对比剂含量的空间变化、软骨下骨的特性以及牛内侧胫骨平台关节软骨的机械硬度。
从新鲜且肉眼完整的牛内侧胫骨平台制备骨软骨样本（n=10）。使用关节镜压痕装置测量样品的动态力学模量。随后，在将样品浸入阴离子碘造影剂（ioxaglate）溶液中 35.5 小时之前和之后，使用外周定量计算机断层扫描（pQCT）设备对样品进行扫描。使用超声和 pQCT 测量软骨的厚度。
在胫骨内侧平台上，动态模量、软骨厚度、软骨下板厚度和浅层软骨中对比剂含量的位置依赖性变化具有统计学意义（P<0.01）。浅层对比剂含量与动态模量之间存在线性相关性，相关系数为 rho=-0.80（P<0.01）。
CECT 能够同时分析对比剂渗透到软骨、软骨厚度和软骨下骨密度和厚度。软骨中的对比剂含量取决于组织的组成和结构。因此，CECT 还提供了关于组织机械性能的间接信息，类似于 dGEMRIC。因此，CECT 可能为体内同时诊断软骨和软骨下骨的完整性提供了手段。
