Improved identification of the palmar fibrocartilage of the navicular bone with saline magnetic resonance bursography.

The research conducted in this paper evaluates if injecting the navicular bursa in a horse’s foot with saline can improve the accuracy of Magnetic Resonance (MR) imaging in detecting degeneration of the palmar fibrocartilage, a common early symptom of navicular disease. The findings show that this method significantly improves both the sensitivity and specificity of MR imaging for this use.

Background

• Navicular disease is a common condition in horses that often presents through degeneration of the palmar fibrocartilage. It is difficult to detect this initial pathological sign with regular MR Imaging.
• The researchers hypothesized that injecting saline into the navicular bursa, a small sac located in the foot of the horse, could enhance the accuracy of MR imaging of this fibrocartilage.

Methodology

• Thoracic limbs were collected from 11 horses within 6 hours of their death. The limbs were then imaged with a 1.5 T magnet using sagittal 2D proton, density, and transverse 3D FLASH sequences.
• Data about the fibrocartilage’s condition was categorized as either normal or abnormal from both a microscopic pathology and a macroscopic examination.
• Fibrocartilage thickness was measured from both histologic sections and their corresponding MR images, both before and after saline injection.
• A paired Student’s t-test was applied to compare the measurements.

Results

• The analysis revealed partial thickness fibrocartilage loss in six of the 22 limbs studied. The sensitivity of pre-contrast MR images for lesion detection was 100%, while specificity was only 6%.
• After injecting saline into the navicular bursa (conducting a saline MR arthrography), both sensitivity and specificity improved to 100%.
• Moreover, the measured fibrocartilage thickness on presaline transverse FLASH images was notably different from that on the histologic sections, but there was no significant difference between the histologic sections and images captured after saline injection.

Conclusion

• The research indicates that injecting saline into the navicular bursa enhances the performance of MR imaging in identifying partial thickness lesions in the palmar fibrocartilage, a common pathological sign of navicular disease.
• This experiment has potential implications for improving early detection and treatment of navicular disease in horses.