Saïed A, Chérin E, Gaucher H, Laugier P, Gillet P, Floquet J, Netter P, Berger G
Laboratoire d'Imagerie Paramétrique CNRS URA, Broussais Hôtel-Dieu, Paris, France.
J Bone Miner Res. 1997 Sep;12(9):1378-86. doi: 10.1359/jbmr.1997.12.9.1378.
The main objectives of this work were to demonstrate the potential of 50 MHz echography for assessing initial and progressive morphological and structural changes of articular cartilage and bone developed in an experimental model of osteoarthritis (OA). Degenerative lesions were induced in rat knees by the unilateral intra-articular injection of a 3 mg dose of mono-iodo-acetic acid. To assess the lesion progression, the animals (n = 30) were sacrificed at different time intervals up to 8 weeks after the injection. Three-dimensional echographic data were acquired in vitro on patellar cartilage and bone at various stages of the remodeling process using a scanning ultrasound microscope. Changes involving the OA cartilage characteristics are discussed relative to those of the contralateral control joint which received a placebo. Images of control cartilage showed a smooth hyperechoic articular surface and an echoic matrix. The cartilage thickness was 266 +/- 44 microns (mean +/- SD) in the central region of the tissue. The precision of ultrasonic thickness measurements was better than 1.3%. First changes in cartilage internal structure and subchondral bone appeared on ultrasound images 3 days after the injection and were even more evident by day 7. They resulted in a slight thinning of the cartilage, a 30% increase of its internal structure echogenicity, and the appearance of echoic zones in subchondral bone. Histologic findings confirmed chondrocyte depletion and degeneration, decrease of matrix proteoglycans, and fibrovascular connective tissue proliferation at the subchondral plate. Progressive and severe lesions at both bone and cartilage surface and internal structure were assessed and correlated to histologic features. These results show that high resolution echography is sensitive to subtle and progressive osteochondral remodeling. This technique has the potential to be used for intra-articular quantitative imaging and assessment of early changes in bone and cartilage structure associated with natural human disease.
本研究的主要目的是证明50兆赫超声检查在评估骨关节炎（OA）实验模型中关节软骨和骨骼的初始及渐进性形态和结构变化方面的潜力。通过单侧关节内注射3毫克单碘乙酸诱导大鼠膝关节出现退行性病变。为评估病变进展，在注射后长达8周的不同时间间隔处死动物（n = 30）。使用扫描超声显微镜在体外获取重塑过程不同阶段髌软骨和骨骼的三维超声数据。相对于接受安慰剂的对侧对照关节，讨论了涉及OA软骨特征的变化。对照软骨图像显示关节表面光滑且呈高回声，基质呈回声。组织中央区域软骨厚度为266 +/- 44微米（平均值 +/- 标准差）。超声厚度测量的精度优于1.3%。注射后3天，软骨内部结构和软骨下骨的最初变化出现在超声图像上，到第7天更加明显。这些变化导致软骨略有变薄，其内部结构回声增强30%，软骨下骨出现回声区。组织学结果证实软骨细胞减少和退变、基质蛋白聚糖减少以及软骨下板处纤维血管结缔组织增生。评估了骨骼和软骨表面及内部结构的渐进性和严重病变，并将其与组织学特征相关联。这些结果表明，高分辨率超声检查对细微和渐进性骨软骨重塑敏感。该技术有潜力用于关节内定量成像以及评估与人类自然疾病相关的骨骼和软骨结构早期变化。
