Do low field magnetic resonance imaging abnormalities correlate with macroscopical and histological changes within the equine deep digital flexor tendon?

The research investigated the relationship between low field magnetic resonance imaging (MRI) indications and macroscopic and histopathological changes in the deep digital flexor tendon (DDFT) of horses. The study found a strong correlation, supporting the use of low field MRI for diagnosing these conditions.

Study Objectives

• The research aimed to establish the effectiveness of low field magnetic resonance (MR) imaging when diagnosing lameness in horses.
• It sought to do this by comparing signal changes in the deep digital flexor tendon (DDFT) as observed on low field MR imaging with actual macroscopical (large-scale, observable) and histological (cellular level, under a microscope) findings.

Methods and Materials

• The study used cadaver limbs from lame horses known to have DDFT lesions.
• The team recorded DDFT MR imaging findings and histopathological results, assigning them grades for later comparison.
• They also noted down any visible macroscopical abnormalities.

Results

• The researchers identified a strong correlation between MR imaging and histopathology grades, with a Spearman’s rank-order correlation coefficients (rs) value of 0.76 (p < 0.001).
• They also noted a moderate agreement (measured by a Kappa statistic of 0.52) between the MR and histopathology grades, with this agreement being better higher in the foot.

Conclusion

• The study concluded that the presence and severity of pathology in the DDFT is adequately represented by the presence and severity of MR imaging signal changes.
• It thus supports the use of low field MR imaging in the diagnosis of equine distal limb DDFT lesions.