Nondestructive assessment of sGAG content and distribution in normal and degraded rat articular cartilage via EPIC-mu CT

作者：Xie L; Lin A S P; Guldberg R E; Levenston M E^*

来源：Osteoarthritis and Cartilage, 2010, 18(1): 65-72.

DOI：10.1016/j.joca.2009.07.014

• EPIC-mu CT
• Microcomputed tomography
• Cartilage development
• Cartilage degradation
• Cartilage imaging

Objective: The objective of this study was to evaluate the feasibility of quantifying the Equilibrium Partitioning of an Ionic Contrast agent via Microcomputed Tomography (EPIC-mu CT) to nondestructively assess sulfated glycosaminoglycan (sGAG) content and distribution in rat articular cartilage ex vivo, and in doing so to establish a paradigm for extension of this technique to other small animal models.
Design: After determination of an appropriate incubation time for the anionic contrast agent, EPIC-mu CT was used to examine age-related differences in cartilage sGAG content between 4-, 8-, and 16-week old (n = 5 each) male Wistar rats and to evaluate sGAG depletion in the right femora of each age group after 60 min of digestion with chondroitinase ABC. The EPIC-mu CT measurements were validated by histological safranin-O staining, and reproducibility was evaluated by triplicate scans of six femora.
Results: Cartilage attenuation gradually increased with cumulative digestion time and reached a plateau at approximately 60 min with a 16.0% temporal increase (P < 0.01). Average femoral articular cartilage attenuation increased by 14.2% from 4- to 8-weeks of age (P < 0.01) and further increased by 2.5% from 8 to 16 weeks (P < 0.05). After 60 min of digestion, femoral articular cartilage attenuations increased by 15-17% in each age group (P < 0.01). Correspondingly, sGAG optical density decreased with age and digestion, and showed a linear correlation (r=-0.88, slope=-1.26, P<0.01, n=30) with EPIC-mu CT cartilage attenuation. High reproducibility was indicated by a low coefficient of variation (1.5%) in cartilage attenuation.
Conclusions: EPIC-mu CT imaging provides high spatial resolution and sensitivity to assess sGAG content and three-dimensional distribution in rat femoral articular cartilage.

• 出版日期2010-1