Brad B Nelson1, Rachel C Stewart2, Chris E Kawcak1, Jonathan D Freedman3, Amit N Patwa4, Brian D Snyder5, Laurie R Goodrich1, Mark W Grinstaff6. 1. Colorado State University, Fort Collins, CO, USA. 2. Imaging Scientist, inviCRO, LLC, Boston, MA, USA. 3. Plastic and Reconstructive Surgery, School of Surgery, University of Colorado, Aurora, CO, USA. 4. Navrachana University, Vadodra, Gujarat, India. 5. Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. 6. Boston University, Boston, MA, USA.
Abstract
OBJECTIVE: To investigate the diffusion trajectory of a cationic contrast medium (CA4+) into equine articular cartilage, and to assess normal and degenerative equine articular cartilage using cationic contrast-enhanced computed tomography (CECT). DESIGN: In the first experiment (Exp1), equine osteochondral specimens were serially imaged with cationic CECT to establish the diffusion time constant and time to reach equilibrium in healthy articular cartilage. In a separate experiment (Exp2), articular cartilage defects were created on the femoral trochlea (defect joint) in a juvenile horse, while the opposite joint was a sham-operated control. After 7 weeks, osteochondral biopsies were collected throughout the articular surfaces of both joints. Biopsies were analyzed for cationic CECT attenuation, glycosaminoglycan (GAG) content, mechanical stiffness (Eeq), and histology. Imaging, biochemical and mechanical data were compared between defect and control joints. RESULTS: Exp1: The mean diffusion time constant was longer for medial condyle cartilage (3.05 ± 0.1 hours) than lateral condyle cartilage (1.54 ± 0.3 hours, P = 0.04). Exp2: Cationic CECT attenuation was lower in the defect joint than the control joint (P = 0.005) and also varied by anatomic location (P = 0.045). Mean cationic CECT attenuation from the lateral trochlear ridge was lower in the defect joint than in the control joint (2223 ± 329 HU and 2667 ± 540 HU, respectively; P = 0.02). Cationic CECT attenuation was strongly correlated with both GAG (ρ = 0.79, P < 0.0001) and Eeq (ρ = 0.61, P < 0.0001). CONCLUSIONS: The equilibration time of CA4+ into equine articular cartilage is affected by tissue volume. Quantitative cationic CECT imaging reflects the biochemical, biomechanical and histological state of normal and degenerative equine articular cartilage.
OBJECTIVE: To investigate the diffusion trajectory of a cationic contrast medium (CA4+) into equine articular cartilage, and to assess normal and degenerative equine articular cartilage using cationic contrast-enhanced computed tomography (CECT). DESIGN: In the first experiment (Exp1), equine osteochondral specimens were serially imaged with cationic CECT to establish the diffusion time constant and time to reach equilibrium in healthy articular cartilage. In a separate experiment (Exp2), articular cartilage defects were created on the femoral trochlea (defect joint) in a juvenile horse, while the opposite joint was a sham-operated control. After 7 weeks, osteochondral biopsies were collected throughout the articular surfaces of both joints. Biopsies were analyzed for cationic CECT attenuation, glycosaminoglycan (GAG) content, mechanical stiffness (Eeq), and histology. Imaging, biochemical and mechanical data were compared between defect and control joints. RESULTS: Exp1: The mean diffusion time constant was longer for medial condyle cartilage (3.05 ± 0.1 hours) than lateral condyle cartilage (1.54 ± 0.3 hours, P = 0.04). Exp2: Cationic CECT attenuation was lower in the defect joint than the control joint (P = 0.005) and also varied by anatomic location (P = 0.045). Mean cationic CECT attenuation from the lateral trochlear ridge was lower in the defect joint than in the control joint (2223 ± 329 HU and 2667 ± 540 HU, respectively; P = 0.02). Cationic CECT attenuation was strongly correlated with both GAG (ρ = 0.79, P < 0.0001) and Eeq (ρ = 0.61, P < 0.0001). CONCLUSIONS: The equilibration time of CA4+ into equine articular cartilage is affected by tissue volume. Quantitative cationic CECT imaging reflects the biochemical, biomechanical and histological state of normal and degenerative equine articular cartilage.
Authors: Rachel C Stewart; Amit N Patwa; Hrvoje Lusic; Jonathan D Freedman; Michel Wathier; Brian D Snyder; Ali Guermazi; Mark W Grinstaff Journal: J Med Chem Date: 2017-06-27 Impact factor: 7.446
Authors: Amir Kol; Boaz Arzi; Kyriacos A Athanasiou; Diana L Farmer; Jan A Nolta; Robert B Rebhun; Xinbin Chen; Leigh G Griffiths; Frank J M Verstraete; Christopher J Murphy; Dori L Borjesson Journal: Sci Transl Med Date: 2015-10-07 Impact factor: 17.956