T2* and quantitative susceptibility mapping in an equine model of post-traumatic osteoarthritis: assessment of mechanical and structural properties of articular cartilage

O Nykänen; J K Sarin; J H Ketola; H Leskinen; N C R Te Moller; V Tiitu; I A D Mancini; J Visser; H Brommer; P R van Weeren; J Malda; J Töyräs; M J Nissi

doi:10.1016/j.joca.2019.06.009

T2* and quantitative susceptibility mapping in an equine model of post-traumatic osteoarthritis: assessment of mechanical and structural properties of articular cartilage

Osteoarthritis Cartilage. 2019 Oct;27(10):1481-1490. doi: 10.1016/j.joca.2019.06.009. Epub 2019 Jul 2.

Authors

O Nykänen¹, J K Sarin², J H Ketola³, H Leskinen⁴, N C R Te Moller⁵, V Tiitu⁶, I A D Mancini⁷, J Visser⁸, H Brommer⁹, P R van Weeren¹⁰, J Malda¹¹, J Töyräs¹², M J Nissi¹³

Affiliations

¹ Department of Applied Physics, University of Eastern Finland, Kuopio, Finland. Electronic address: olli.nykanen@uef.fi.
² Department of Applied Physics, University of Eastern Finland, Kuopio, Finland; Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland. Electronic address: jaakko.sarin@uef.fi.
³ Department of Applied Physics, University of Eastern Finland, Kuopio, Finland; Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland. Electronic address: juuso.ketola@oulu.fi.
⁴ Department of Applied Physics, University of Eastern Finland, Kuopio, Finland. Electronic address: henriles@uef.fi.
⁵ Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. Electronic address: N.C.R.teMoller@uu.nl.
⁶ Institute of Biomedicine, Anatomy, University of Eastern Finland, Kuopio, Finland. Electronic address: virpi.tiitu@uef.fi.
⁷ Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. Electronic address: I.A.D.Mancini@uu.nl.
⁸ Department of Orthopaedics, University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: jetzevisser.jv@gmail.com.
⁹ Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. Electronic address: H.Brommer@uu.nl.
¹⁰ Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. Electronic address: r.vanweeren@uu.nl.
¹¹ Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands; Department of Orthopaedics, University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: J.Malda@umcutrecht.nl.
¹² Department of Applied Physics, University of Eastern Finland, Kuopio, Finland; Diagnostic Imaging Center, Kuopio University Hospital, Kuopio, Finland; School of Information Technology and Electrical Engineering, The University of Queensland, Brisbane, Australia. Electronic address: j.toyras@uq.edu.au.
¹³ Department of Applied Physics, University of Eastern Finland, Kuopio, Finland; Research Unit of Medical Imaging, Physics and Technology, University of Oulu, Oulu, Finland. Electronic address: mikko.nissi@uef.fi.

PMID: 31276818
DOI: 10.1016/j.joca.2019.06.009

Abstract

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.

Keywords: Articular cartilage; Post-traumatic osteoarthritis; Quantitative susceptibility mapping; T2* relaxation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Biomechanical Phenomena
Cartilage, Articular / diagnostic imaging
Cartilage, Articular / injuries
Cartilage, Articular / pathology*
Cartilage, Articular / physiopathology*
Disease Models, Animal
Disease Susceptibility
Female
Horses
Magnetic Resonance Imaging
Male
Osteoarthritis / diagnostic imaging
Osteoarthritis / etiology
Osteoarthritis / pathology*
Osteoarthritis / physiopathology*