Myers S L, Dines K, Brandt D A, Brandt K D, Albrecht M E
Rheumatology Division, Indiana University School of Medicine, Indianapolis 46202-5103.
J Rheumatol. 1995 Jan;22(1):109-16.
Osteoarthritis (OA) is characterized by progressive loss of articular cartilage in the involved joint. Accurate, reproducible measurement of the thickness of the cartilage in vivo, however, is difficult. Because development of an ultrasonic imaging device for intraarticular use is feasible and would permit acquisition of information that could complement the assessment of articular cartilage made at arthroscopy, we evaluated the efficacy of high frequency ultrasound in assessing the thickness and subsurface characteristics of normal and OA cartilage.
Blocks of human femoral cartilage and subchondral bone and chips of cartilage alone were examined in vitro with an experimental 25 MHz pulse-echo ultrasound scanner that portrayed cross sections of the cartilage as B-mode images. The gross and histologic appearance of the articular surface was used to identify specimens of unblemished, normal cartilage and OA cartilage. The speed of sound in cartilage, determined from measurements of cartilage thickness and sound transmission, was related to its biochemical composition.
The speed of sound in normal cartilage (1658 +/- 185 m/s, n = 27) was greater than that in OA cartilage (1581 +/- 148 m/s, n = 40, p = 0.06), but was not related to the cartilage water content or the concentration of uronic acid or hydroxyproline. Images of normal cartilage showed a smooth echo band at the tissue surface with a hypoechoic matrix; in scans of fibrillated cartilage the width of this band was proportional to the depth of fibrillation (r = 0.78). Ultrasonic and histologic measurements of OA cartilage thickness were closely correlated (r = 0.87) and the mean coefficient of variation for repeated measurements was 2%.
High frequency ultrasonic images obtained in vitro provide highly accurate and reproducible measurements of the thickness and subsurface characteristics of normal and OA articular cartilage.
骨关节炎（OA）的特征是受累关节的关节软骨逐渐丧失。然而，在体内准确、可重复地测量软骨厚度是困难的。由于开发一种用于关节内使用的超声成像设备是可行的，并且可以获取能够补充关节镜检查时对关节软骨评估的信息，我们评估了高频超声在评估正常和OA软骨厚度及表面下特征方面的功效。
使用实验性的25兆赫脉冲回波超声扫描仪对人体股骨软骨和软骨下骨块以及单独的软骨碎片进行体外检查，该扫描仪将软骨的横截面描绘为B模式图像。关节表面的大体和组织学外观用于识别无瑕疵的正常软骨和OA软骨标本。通过测量软骨厚度和声传播来确定软骨中的声速，该声速与其生化组成有关。
正常软骨中的声速（1658±185米/秒，n = 27）高于OA软骨中的声速（1581±148米/秒，n = 40，p = 0.06），但与软骨含水量、糖醛酸或羟脯氨酸浓度无关。正常软骨的图像在组织表面显示出一条光滑的回声带，其基质为低回声；在纤维化软骨的扫描中，这条带的宽度与纤维化深度成正比（r = 0.78）。OA软骨厚度的超声测量和组织学测量密切相关（r = 0.87），重复测量的平均变异系数为2%。
体外获得的高频超声图像能提供正常和OA关节软骨厚度及表面下特征的高度准确且可重复的测量结果。
