Department of Sensory and Motor System Medicine, Faculty of Medicine, University of Tokyo, Tokyo, Japan.
Ultrasound Med Biol. 2012 Feb;38(2):324-34. doi: 10.1016/j.ultrasmedbio.2011.11.012.
The present study aimed to quantify the thickness of articular cartilage (Tc) in vitro using both conventional and real-time spatial compound B-mode ultrasonography (US) with a clinically used transducer and to evaluate the accuracy of measurement by comparing the results with values obtained microscopically. Femoral condyle samples were obtained from a 6-month-old pig and a 3-year-old pig. B-mode US images with conventional imaging and real-time spatial compound imaging (RTSCI) of osteochondral blocks were acquired. Tc determined using US (Tc-US) was measured from line data parallel to US beam direction acquired from B-mode images with an objective method for determining cartilage surface and bone-cartilage interfaces at the peak brightness values. Tc was also determined under microscopy (Tc-optical) using the corresponding points from US measurement. Tc-US was compared with Tc-optical to assess accuracy. Tc-US correlated significantly with Tc in both conventional imaging and RTSCI (r = 0.961, 0.976, respectively). Bland-Altman plots showed mean differences between Tc-optical and Tc-US were -0.0073 mm and 0.0139 mm with standard deviations of 0.171 mm and 0.131 mm for conventional imaging and RTSCI, respectively. Our results show that Tc-US measurement using B-mode US allows accurate measurement of Tc. Considering correlation coefficients between Tc-US and Tc-optical, RTSCI US may offer higher accuracy for measuring Tc than conventional methods when an objective tissue border determination algorithm is used, even though both showed good accuracy in our study.
本研究旨在使用临床使用的换能器通过常规和实时空间复合 B 型超声（US）来量化关节软骨（Tc）的体外厚度，并通过将结果与显微镜下获得的值进行比较来评估测量的准确性。从 6 个月大的猪和 3 岁大的猪获得股骨髁样本。采集骨软骨块的常规成像和实时空间复合成像（RTSCI）的 B 型 US 图像。使用客观方法从 B 型图像中获取与 US 光束方向平行的线数据来确定 US （Tc-US），以确定软骨表面和骨软骨界面的峰值亮度值。还使用来自 US 测量的对应点在显微镜下（Tc-光学）确定 Tc。将 Tc-US 与 Tc-光学进行比较以评估准确性。Tc-US 与传统成像和 RTSCI 中的 Tc 均呈显著相关（r = 0.961、0.976）。Bland-Altman 图显示 Tc-光学和 Tc-US 之间的平均差异分别为 -0.0073mm 和 0.0139mm，其标准偏差分别为 0.171mm 和 0.131mm。我们的结果表明，使用 B 型 US 的 Tc-US 测量可准确测量 Tc。考虑到 Tc-US 和 Tc-光学之间的相关系数，当使用客观的组织边界确定算法时，RTSCI US 可能比传统方法具有更高的 Tc 测量精度，尽管在我们的研究中这两种方法都具有很好的精度。
