The aim of this study was to determine whether delayed – gadolinium enhanced magnetic resonance imaging of the cartilage (dGEMRIC) and T2 mapping are accurate techniques for measuring cartilage thickness in the distal interphalangeal joint of Warmblood horses.
Twelve cadaver forelimbs were acquired from twelve horses with a mean age of 15 years showing no signs of lameness. Cartilage thickness was measured from dGEMRIC (T1) and T2 images in 9 regions of interest (ROIs) in the distal cartilage of the middle phalanx (P2) and in 9 ROIs in the proximal cartilage of the distal phalanx (P3). The measurements from the MRI were compared with the cartilage thicknesses measured in the corresponding histological images. The histological sections were classified into three groups of cartilage health.
The T1, T2 as well as the histological measurements showed that the site within the joint and the joint disease state have a significant effect on the cartilage thickness. An increasing degree of osteoarthritis leads to a decreasing cartilage thickness. The histological measurements significantly correlated with the T1 and T2 cartilage thickness measurements. The correlation between the T1 measurements and the histological measurements were always better than the T2 measurements compared to the histological measurements. Based on these results, the normal or degenerated equine articular cartilage can be evaluated by T1 or T2 maps at areas of opposing or non-opposing cartilage surfaces.