Magnetic resonance imaging of the equine digit with chronic laminitis.
Authors: Murray, Dyson, Schramme, Branch, Woods
Journal: Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association
Summary
# Editorial Summary Chronic laminitis remains one of the most challenging conditions to diagnose and monitor in equine practice, and whilst radiography has long been the gold standard for assessment, it provides limited visualisation of soft tissue pathology within the digit. Murray and colleagues used cadaver limbs from ten horses with chronic laminitis and ten controls to compare magnetic resonance (MR) imaging with conventional radiography, employing both sagittal and transverse MR sequences to characterise structural changes in the foot. MR imaging revealed numerous pathological findings invisible on radiographs—including laminar disruption, circumscribed areas of laminar gas and fluid accumulation, increased vascular channels, corium coronae alterations, and distal interphalangeal joint distension—whilst also providing superior definition of gas lines and P3 surface irregularities. Laminitic feet demonstrated significantly greater dorsal hoof wall thickness, increased distal phalanx rotation and displacement compared to normal feet, with forelimbs showing greater wall thickness than hindlimbs. For practitioners involved in chronic laminitis cases, these findings suggest that MR imaging could substantially enhance diagnostic capability and potentially guide more targeted therapeutic interventions, though the practical application in clinical settings will depend on accessibility and cost considerations.
Read the full abstract on PubMed
Practical Takeaways
- •MR imaging reveals soft tissue pathology in chronic laminitis (laminar damage, fluid, gas) that standard radiographs miss—consider MR when radiographs appear inconclusive or progression seems unexplained
- •Distal phalanx rotation, displacement distance, and hoof wall thickness are measurable biomarkers of chronic laminitis severity that can be quantified on MR images for monitoring disease progression
- •MR imaging should be used alongside radiography for comprehensive assessment of chronic laminitis cases, especially when planning farriery interventions or evaluating prognosis
Key Findings
- •MR imaging detected laminar disruption, circumscribed laminar gas, laminar fluid, and bone medullary fluid in chronic laminitis cases that were not visible on radiographs
- •Chronic laminitis group showed greater distal phalanx rotation angle, greater distal displacement, and greater dorsal hoof wall thickness compared to control group
- •MR imaging provided superior definition of laminar gas lines and P3 surface irregularity compared to radiography
- •Additional MR findings included increased vascular channels, corium coronae alterations, and distal interphalangeal joint distension not detected radiographically