Validation of magnetic resonance imaging for measurement of equine articular cartilage and subchondral bone thickness.

The research validates the use of magnetic resonance imaging (MRI) in accurately measuring the thickness of horses’ joint cartilage and underlying bone, aiding in the study and clinical diagnosis of joint conditions.

Research Methods

• The researchers pursued their goal by analyzing MRIs from 32 cadaveric carpal (wrist) joints. These were obtained from 16 horses.
• The MRI procedure used two types of pulse sequences, namely, 3D fast spoiled gradient echo (SPGR) and T2* 3D fast gradient echo (GRE), both with and without fat saturation.
• For both the articular cartilage and the subchondral bone thickness measurements, standard positions were used on the medial and lateral aspects of specific carpal bones.
• Using digital image analysis software, MRI measurements were taken 10 mm from the dorsal extent and perpendicular to the articular surface.
• Histomorphometric measurements, a technique for studying the microscopic structure of tissues, were used to measure the thickness of the hyaline, calcified cartilage and subchondral bone at selected sites.
• The measurements from the MRI and histomorphometric methods were compared, as well as the results from the different magnetic resonance pulse sequences.

Research Findings

• The researchers found noteworthy correlations between the GRE and SPGR sequences, and between SPGR and histologic measurements of articular cartilage.
• The MRIs did not show any significant difference from the histologic measurements, indicating good consistency between the two techniques. However, when calcified cartilage was excluded from the histologic measurement, MRI measurements showed significantly greater values.
• For the underlying bone thickness, there was a significant correlation between GRE and SPGR. But, GRE measurements were significantly higher than SPGR measurements.
• When comparing the MRI-based and histomorphometric measurements, the researchers found strong correlation and no significant discrepancy between the two methodologies.

Conclusion

• The study concluded that magnetic resonance imaging provides accurate and consistent measurements of cartilage and subchondral bone thickness in horses.
• The strong correlations and lack of significant differences between the MRI and traditional histomorphometric measurements confirm that MRI is a valid method for studying and diagnosing osteochondral structure and changes, thus advocating its use in both research and clinical settings.