Use of concurrent scintigraphic and magnetic resonance imaging evaluation to improve understanding of the pathogenesis of injury of the podotrochlear apparatus.

The researchers in this study used both scintigraphic (radioactive imaging) and magnetic resonance imaging (MRI) techniques to gain a clearer understanding of how foot pain in horses occurs. Examining a large number of horses, they derived important correlations between the imaging findings and the pain symptoms. The gathered data contribute to our understanding of equine podotrochlear disease, and could help in developing more targeted treatments.

Research methods

• Simultaneous scintigraphic and MRI images were taken from 264 horses presenting unilateral or bilateral foot pain.
• These images were then analysed and graded based on several criteria, like the radiopharmaceutical uptake (IRU) in the navicular bone (small bone in the hoof), and the distribution and changes in signal intensity observed in MRIs.
• Spearman rank correlation tests were conducted to find any potential relationships between the scintigraphic grading and the MRI scores for each section of the bone.
• Additional chi-square tests were conducted to look for associations between scintigraphy grade and increased signal intensities, as well as the presence of focal and diffuse IRU across different MRI grades.

Research findings

• It was found that there were significant positive correlations between the scintigraphy grade and both the maximum and total MRI grades for the navicular bone. The scintigraphy grade also showed a correlation with MRI grades for key areas of the bone like the flexor border, distal border, and medulla.
• Despite these correlations, the study observed no variation in the proportions of focal and diffuse IRU across different navicular bone MRI grades. The diffused IRU was notably less present in Grade 3 navicular bones.
• No clear association was established between increased IRU in the navicular bone and magnetic resonance lesions, whether at the DSIL origin or the CSL insertion. A correlation was identified, however, between IRU and combined lesions of the CSL, DSIL, and navicular bursa.
• For limbs with a specific type of lesion known as DDFT, navicular bone scintigraphic Grades 2 and 3 were more commonly observed.

Conclusions

• The study concluded that scintigraphy and MRI could complement each other in providing multiple sources of information about the development of lesions in the podotrochlear apparatus
• A greater understanding of these disease processes, accorded by the simultaneous use of these imaging methods, could eventually lead to more effective, customised treatments for foot pain in horses.