Quantitative Ultrasound Assessment of Cartilage Degeneration in Ovariectomized Rats with Low Estrogen Levels.
The aim of this study was to assess quantitatively the site-specific degeneration of articular cartilage in ovariectomized rats with low estrogen levels using a high-frequency ultrasound system. Fourteen female Sprague-Dawley rats were randomly divided into two groups (n = 7 per group): a sham group in which only the peri-ovarian fatty tissue was exteriorized and an ovariectomized group that underwent bilateral ovariectomy to create a menopause model with low estrogen levels. All animals were sacrificed at the end of the third week after ovariectomy. Hindlimbs were harvested. The articular cartilage from five anatomic sites (i.e., femoral caput [FC], medial femoral condyle [MFC], lateral femoral condyle [LFC], medial tibial plateau [MTP] and lateral tibial plateau [LTP]) was examined with ultrasound. Four parameters were extracted from the ultrasound radiofrequency data: reflection coefficient of the cartilage surface (RC1), reflection coefficient of the cartilage-bone interface (RC2), ultrasound roughness index (URI) and thickness of the cartilage tissue. The results indicated significant (p < 0.05) site dependence for cartilage thickness, URI and RC1 in the sham group. The 3-wk post-menopause ovariectomized rats exhibited significant increases (p < 0.05) in the URI at the LFC, MTP and LTP; significant decreases (p < 0.05) in RC1 at the FC, LFC and MTP; and significant decreases (p < 0.05) in cartilage thickness at the MFC, LFC, MTP and LTP. These results of this study suggest that post-menopausal estrogen reduction induces morphologic and acoustic alterations in the articular cartilage of the hip and knee joints in ovariectomized rats.
Institute of Medical Information, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Medical Image Processing, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China. Electronic address: wq8740@smu.edu.cn.
Qing
Q
Wang
Institute of Medical Information, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China.
Zhiwei
Z
Liu
Institute of Medical Information, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China.
Yinong
Y
Wang
Institute of Medical Information, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China.
Qingya
Q
Pan
Institute of Medical Information, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Medical Image Processing, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China. Electronic address: qianjinfeng08@gmail.com.
Qianjin
Q
Feng
School of Electronic and Information Engineering, South China University of Technology, Guangzhou, Guangdong, China.
Qinghua
Q
Huang
Institute of Medical Information, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Medical Image Processing, School of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong, China.
Wufan
W
Chen
D000818:Animals; D002357:Cartilage Diseases / Q000000981:diagnostic imaging*; D002358:Cartilage, Articular / Q000000981:diagnostic imaging*; D004195:Disease Models, Animal; D004967:Estrogens; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging; D006614:Hindlimb / Q000000981:diagnostic imaging; D010003:Osteoarthritis / Q000000981:diagnostic imaging*; D017698:Postmenopause; D051381:Rats; D017207:Rats, Sprague-Dawley; D013977:Tibia / Q000000981:diagnostic imaging; D014463:Ultrasonography
D004967:Estrogens
Cartilage degradation; Estrogen; High-frequency ultrasound; Ovariectomized rat; Post-menopause