Non-contrast enhanced visualization of the equine foot vasculature in a cadaver model using time-of-flight sequence.
Authors: Underberg Bianca A, Kaessmeyer Sabine, Schweizer Daniela, Drews Barbara, Van der Vekens Elke
Journal: Frontiers in veterinary science
Summary
# Editorial Summary Researchers have developed a non-contrast enhanced MRI protocol capable of visualising the equine foot's fine vasculature without requiring contrast injection—a significant advance for diagnostic imaging that could eventually reduce the need for invasive angiography or experimental animal use. Working with cadaver feet perfused with paraffin oil, the team optimised three-dimensional time-of-flight (3D-TOF) sequences across multiple scanning planes, testing 74 different parameter combinations to identify the optimal settings. The refined protocol successfully imaged vessels as small as the sublamellar plexus (approximately 0.45 mm diameter), with dorsal plane acquisition offering a practical advantage by capturing nearly the entire foot within a single 22-minute scan whilst maintaining visualisation quality comparable to transverse imaging. For equine practitioners, this technique offers potential applications in investigating chronic laminitis, navicular disease, and other vascular-related foot pathologies without the radiation exposure, expense, or contrast agent risks associated with current imaging modalities. The establishment of this protocol using post-mortem tissue rather than live animal models also represents an ethical advancement in equine MRI methodology development.
Read the full abstract on PubMed
Practical Takeaways
- •Non-contrast TOF-MRA offers a safe alternative imaging method for detailed equine foot vascular anatomy without need for gadolinium contrast agents
- •The established sequence parameters can enable improved diagnostic visualization of foot vasculature in cases of navicular syndrome, laminitis, or other vascular-related lameness
- •Dorsal plane acquisition is clinically preferable as it visualizes the entire foot within a single protocol while maintaining sublamellar plexus detail
Key Findings
- •3D-TOF MR angiography successfully visualized vessels as small as the sublamellar plexus (0.45 mm diameter) without contrast enhancement
- •Optimal parameters for equine foot imaging: pixel size 0.34 × 0.48 mm, slice thickness 0.2 mm, TR/TE 21.2/4.7 ms, flip angle 16°, with 22.05 min acquisition time
- •Transverse orientation superior for sublamellar plexus visibility; dorsal orientation achieved equivalent visualization while including entire foot in field of view
- •Post-mortem cadaver model with paraffin oil perfusion enabled sequence development without requiring live experimental animals