Comparison of high-field and low-field magnetic resonance images of cadaver limbs of horses.

The research studied the effectiveness of high-field and low-field magnetic resonance imaging (MRI) in examining the limbs of deceased horses. It found that while both types of MRI can detect abnormalities in tissues, high-field MRI revealed finer details, particularly in the articular cartilage.

Study Design and Methodology

• The researchers used eleven limbs from ten different horses that were suffering from lameness. The postmortem examination was done using MRI.
• For the imaging tests, a low-field 0.27T system was used which is normally used for standing horses. On the other hand, a high-field 1.5T system, which is typically used for anaesthetised horses, was also utilized.
• The foot/pastern region was examined in nine limbs while the fetlock region was observed in two limbs.
• The results of these MRIs were then compared with the gross pathological examinations and histological examinations done on selected tissues from the same limbs.

Findings of the Study

• The normal tissues appeared similar in both the low-field and high-field MRI systems. Differences in the anatomical arrangement of the structures were attributed to diffferent positions in the MRI machines.
• A phenomenon known as ‘magic angle artefact’ was seen at different sites in some imaging sequences.
• High-field MRI allowed differentiation of articular cartilage into two articular surfaces in most joints. In contrast, low-field MRI images generally only separated these surfaces at the joints’ margins.
• Abnormalities in tendon, ligament, and bone detected in the gross examination were also detected in both MRI systems. High-field images, however, provided clearer detail on such abnormalities.
• Lesions found in the articular cartilage during pathological examinations were only recognized via high-field MRI.
• All limbs with abnormal pathology in the navicular flexor fibrocartilage were also identified as having abnormalities through MRI.

Conclusion and Implications

• The research indicates that while both forms of MRI – high-field and low-field – can detect abnormalities in the limbs of horses, high-field MRI tends to provide more detailed information.
• This can be particularly crucial for diagnosing lesions in the articular cartilage, thereby aiding more effective treatments for lameness in horses.
• The findings suggest an advantage in using high-field MRI systems when examining horses, especially if cartilage issues are suspected.