MRI assessment of cartilage ultrastructure

Abstract

In T 2 -weighted MRI images joint cartilage can appear laminated. The multilaminar appearance is visualized as zones of different intensity. This appearance is based on the dipolar interaction of water molecules within cartilage zones of different collageneous network structures. Therefore, the MR visualization of zones of anisotropic arrangement of the collagen fibers depends upon their orientation to the static magnetic field (magic-angle effect). The aim of this article is to demonstrate the potential of high-resolution MRI for characterizing cartilage network structuring and biomechanical properties. Information equivalent to that from polarization light microscopy can be derived noninvasively. Based on NMR microscopic (mMRI) data, potential new possibilities of MRI for quantitative assessment of collagen structuring and intracartilagenous load distribution are presented. These methods use MR intensity angle dependence and load influence on cartilage visualization. Alternatively to the determination of mechanical parameters from cartilage deformation, it is demonstrated that stress distribution and biomechanical properties can be derived in principle from the local intensity variation of anisotropic fiber orientation zones. The limitations with respect to a clinical application of the proposed methods are discussed.

Foetal and postnatal equine articular cartilage development: magnetic resonance imaging and polarised light microscopy

“…In contrast to the adult cartilage appearance on MRI, with three zones, up to seven zones of different intensity have already been observed in juvenile femoral cartilage on MRI in various species (Grunder, 2006;Grunder et al, 2000;Grunder et al, 1998;Nieminen et al, 2000;Nissi et al, 2006;Xia et al, 2003). Fig.…”

“…These differences reflect site and joint maturational differences (Lecocq et al, 2008), also observed by others (Brama et al, 2000;Julkunen et al, 2010). Grunder (2006) postulates that the site-related variation of cartilage laminae on MRI is an adaptation of the collagenous network to the regional different "biochemical requirements". Variations in collagen network organisation are also observed in young animals at different sites within the joint (Hyttinen et al, 2009) and also between different articular surfaces (Julkunen et al, 2010).…”

The development of the collagen fibre network in tissue-engineered cartilage constructs in vivo. Engineered cartilage reorganises fibre network

“…These patterns have been confi rmed using polarised light microscopy (Hughes et al, 2005;Julkunen et al, 2009;Rieppo et al, 2009) and -MRI (Alhadlaq et al, 2004;Gründer, 2006;Nissi et al, 2006;Seidel et al, 2005;Xia et al, 2003). None of these studies has investigated the development of the fi bre orientation within in vivo implanted tissue-engineered cartilage over time.…”

Review on Patents for Mechanical Stimulation of Articular Cartilage Tissue Engineering

“…However, the use of such probes is limited to in vitro cultures and cannot be used in implants. A second and probably more versatile example is the use of other measure-ment systems such as MRI or ultrasound elastomicrography imaging to follow tissue development [99][100][101]. Although, these techniques may provide ample information of the development of matrix throughout the construct, it has obvious drawbacks related to usability and cost-effectiveness.…”