Ex vivo comparison of 3 Tesla magnetic resonance imaging and multidetector computed tomography arthrography to identify artificial soft tissue lesions in equine stifles.
Authors: Aßmann Anton D, Ohlerth Stefanie, Suárez Sánchez-Andráde José, Torgerson Paul R, Bischofberger Andrea S
Journal: Veterinary surgery : VS
Summary
# Editorial Summary Diagnosing soft tissue injuries within the equine stifle—particularly meniscal tears, meniscotibial ligament (MTL) damage, and cruciate ligament (CL) lesions—remains clinically challenging, prompting Aßmann and colleagues to compare the diagnostic utility of 3 Tesla MRI and contrast-enhanced computed tomography arthrography (CTA) in a controlled ex vivo setting using 19 equine stifles with artificially created stablike defects (16 mm long, 10 mm deep). Two independent radiologists, blinded to lesion locations, reviewed both imaging modalities; whilst MRI demonstrated 41% sensitivity and 86% specificity compared to CTA's 32% sensitivity and 90% specificity, these differences were not statistically significant (P = .65), with sensitivity ranging broadly between modalities depending on tissue type (MRI achieved 50% sensitivity for MTL lesions and both techniques reached 40% for CL injuries). Both imaging methods proved disappointing for meniscal detection (24–40% sensitivity across both modalities) but showed consistently high specificity (75–100%), suggesting that when lesions are identified on either modality, they are likely genuine, though absence of imaging findings cannot exclude pathology. For practitioners, CTA emerges as a viable alternative to MRI—particularly valuable given that cruciate ligament injuries cannot be adequately visualised on routine radiography—though the moderate sensitivity of both techniques underscores the continued importance of arthroscopy as the gold standard for definitive diagnosis of stifle soft tissue injuries.
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Practical Takeaways
- •CTA can be used as an alternative to MRI for evaluating cruciate ligament injuries when MRI is unavailable, as basic imaging cannot adequately visualize CL injuries preoperatively
- •Neither MRI nor CTA is highly sensitive (41% and 32% respectively) for detecting stifle soft tissue lesions, so negative findings should not exclude these injuries—arthroscopy remains the gold standard for diagnosis
- •When evaluating meniscotibial ligaments, MRI shows slightly better sensitivity (50% vs 40%) than CTA, which may guide modality selection in clinical practice
Key Findings
- •MRI sensitivity 41% and specificity 86%; CTA sensitivity 32% and specificity 90% with no significant difference between modalities (P=0.65)
- •MTL evaluation with MRI achieved highest sensitivity (50%) while both modalities achieved 40% sensitivity for CL lesions
- •Both imaging modalities demonstrated low to moderate sensitivity but high specificity for detecting artificial soft tissue lesions in equine stifles
- •CTA diagnostic performance was comparable to 3T MRI for detecting meniscal, MTL, and CL lesions in this ex vivo study