TY - JOUR
T1 - T2* and quantitative susceptibility mapping in an equine model of post-traumatic osteoarthritis
T2 - assessment of mechanical and structural properties of articular cartilage
AU - Nykänen, Olli
AU - Sarin, Jaakko K
AU - Ketola, Juuso H
AU - Leskinen, Henri
AU - Te Moller, Nikae C R
AU - Tiitu, Virpi
AU - Mancini, Irina A D
AU - Visser, Jetze
AU - Brommer, Harold
AU - René van Weeren, P
AU - Malda, Jos
AU - Töyräs, Juha
AU - Nissi, Mikko J
N1 - Funding Information:
Support from the Academy of Finland (grants #285909 , #293970 , and #319440 ), The Northern Savo Regional Fund of the Finnish Cultural Foundation (grant #65161539 ), the Finnish Cultural Foundation (grant #00180787 ) and the Dutch Arthritis Foundation, the Netherlands (grants LLP-12 and LLP-22 ) are gratefully acknowledged. Help from Mr. Abdul Wahed Kajabi in PLM-imaging is gratefully acknowledged.
Publisher Copyright:
© 2019 The Author(s)
PY - 2019/10/1
Y1 - 2019/10/1
N2 - Objective: To investigate the potential of quantitative susceptibility mapping (QSM) and T2* relaxation time mapping to determine mechanical and structural properties of articular cartilage via univariate and multivariate analysis. Methods: Samples were obtained from a cartilage repair study, in which surgically induced full-thickness chondral defects in the stifle joints of seven Shetland ponies caused post-traumatic osteoarthritis (14 samples). Control samples were collected from non-operated joints of three animals (6 samples). Magnetic resonance imaging (MRI) was performed at 9.4 T, using a 3-D multi-echo gradient echo sequence. Biomechanical testing, digital densitometry (DD) and polarized light microscopy (PLM) were utilized as reference methods. To compare MRI parameters with reference parameters (equilibrium and dynamic moduli, proteoglycan content, collagen fiber angle and -anisotropy), depth-wise profiles of MRI parameters were acquired at the biomechanical testing locations. Partial least squares regression (PLSR) and Spearman's rank correlation were utilized in data analysis. Results: PLSR indicated a moderate-to-strong correlation (ρ = 0.49–0.66) and a moderate correlation (ρ = 0.41–0.55) between the reference values and T2* relaxation time and QSM profiles, respectively (excluding superficial-only results). PLSR correlations were noticeably higher than direct correlations between bulk MRI and reference parameters. 3-D parametric surface maps revealed spatial variations in the MRI parameters between experimental and control groups. Conclusion: Quantitative parameters from 3-D multi-echo gradient echo MRI can be utilized to predict the properties of articular cartilage. With PLSR, especially the T2* relaxation time profile appeared to correlate with the properties of cartilage. Furthermore, the results suggest that degeneration affects the QSM-contrast in the cartilage. However, this change in contrast is not easy to quantify.
AB - Objective: To investigate the potential of quantitative susceptibility mapping (QSM) and T2* relaxation time mapping to determine mechanical and structural properties of articular cartilage via univariate and multivariate analysis. Methods: Samples were obtained from a cartilage repair study, in which surgically induced full-thickness chondral defects in the stifle joints of seven Shetland ponies caused post-traumatic osteoarthritis (14 samples). Control samples were collected from non-operated joints of three animals (6 samples). Magnetic resonance imaging (MRI) was performed at 9.4 T, using a 3-D multi-echo gradient echo sequence. Biomechanical testing, digital densitometry (DD) and polarized light microscopy (PLM) were utilized as reference methods. To compare MRI parameters with reference parameters (equilibrium and dynamic moduli, proteoglycan content, collagen fiber angle and -anisotropy), depth-wise profiles of MRI parameters were acquired at the biomechanical testing locations. Partial least squares regression (PLSR) and Spearman's rank correlation were utilized in data analysis. Results: PLSR indicated a moderate-to-strong correlation (ρ = 0.49–0.66) and a moderate correlation (ρ = 0.41–0.55) between the reference values and T2* relaxation time and QSM profiles, respectively (excluding superficial-only results). PLSR correlations were noticeably higher than direct correlations between bulk MRI and reference parameters. 3-D parametric surface maps revealed spatial variations in the MRI parameters between experimental and control groups. Conclusion: Quantitative parameters from 3-D multi-echo gradient echo MRI can be utilized to predict the properties of articular cartilage. With PLSR, especially the T2* relaxation time profile appeared to correlate with the properties of cartilage. Furthermore, the results suggest that degeneration affects the QSM-contrast in the cartilage. However, this change in contrast is not easy to quantify.
KW - Articular cartilage
KW - Post-traumatic osteoarthritis
KW - Quantitative susceptibility mapping
KW - T2 relaxation
KW - T2relaxation
UR - http://www.scopus.com/inward/record.url?scp=85069553367&partnerID=8YFLogxK
U2 - 10.1016/j.joca.2019.06.009
DO - 10.1016/j.joca.2019.06.009
M3 - Article
C2 - 31276818
SN - 1063-4584
VL - 27
SP - 1481
EP - 1490
JO - Osteoarthritis and Cartilage
JF - Osteoarthritis and Cartilage
IS - 10
ER -