Ultrasonography as a method to determine tendon cross-sectional area

Area of Science:

• Veterinary Medicine
• Equine Science
• Diagnostic Imaging

Background:

• Accurate measurement of equine superficial digital flexor tendon (SDFT) cross-sectional area (CSA) is crucial for diagnosing and managing tendon injuries.
• Traditional methods like ink-blot analysis are invasive and may not reflect in vivo conditions.

Purpose of the Study:

• To determine the feasibility of ultrasonography for measuring SDFT CSA in live horses (in vivo) and post-mortem (in vitro).
• To compare ultrasonographic CSA measurements with a traditional ink-blot analysis method.
• To evaluate SDFT mean echogenicity using ultrasonography in vivo and in vitro.

Main Methods:

• Ultrasonographic cross-sectional images of SDFTs from 23 horses were acquired at standardized locations.
• Measurements were taken while horses were standing (in vivo) and after euthanasia under tension (in vitro) using a materials testing system (MTS).
• Ultrasonographic images were compared with morphologic CSA derived from ink-blot analysis of tendon sections.

Main Results:

• Ultrasonographic CSA measurements showed strong positive linear correlations with ink-blot analysis (R2 = 0.64–0.72, P = 0.001).
• Standing ultrasonographic CSA was consistently smaller than MTS or ink-blot measurements.
• Mean echogenicity values were slightly higher in vivo compared to in vitro, with insignificant differences.

Conclusions:

• Ultrasonography is a feasible and reliable noninvasive technique for assessing SDFT CSA in horses.
• The method demonstrates strong correlation with traditional morphologic measurements, validating its use in both live and post-mortem evaluations.
• Ultrasonography offers a valuable tool for in vivo assessment of equine tendon structures.