Reliability of ultrasonography compared to radiography in revealing intestinal sand accumulations in horses.
Authors: Korolainen R, Ruohoniemi M
Journal: Equine veterinary journal
Summary
# Editorial Summary Korolainen and Ruohoniemi (2002) examined whether ultrasonography could reliably detect intestinal sand accumulations in 32 horses presenting with gastrointestinal signs, comparing ultrasound findings against radiographic grading and assessing sensitivity and specificity of each modality. Both techniques showed significant association, with ultrasonography demonstrating 87.5% sensitivity and specificity overall; notably, 13 of 14 horses (92.9%) with moderate-to-large ventral sand accumulations on radiographs were correctly identified ultrasonographically, though detection was compromised for small or dorsally-positioned collections. Ultrasonographic signs included hyperechoic sand at the ventral aspect with acoustic shadowing and reduced intestinal motility, reliably revealing accumulation length but providing limited information on depth. Whilst ultrasonography proved a practical bedside tool suitable for field assessment, the authors concluded it cannot fully replace radiography, particularly where small deposits or cranial/dorsal localisation is suspected—a finding emphasising the complementary value of these modalities in sand colic investigation and management.
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Practical Takeaways
- •Ultrasonography is a practical, reliable field-applicable alternative to radiography for detecting moderate to large ventral sand accumulations in horses with colic signs
- •Combine ultrasonography with radiography for complete assessment, as ultrasound cannot reliably detect small or dorsally located sand and provides limited height information
- •Use ultrasonographic findings of hyperechoic sand with acoustic shadowing and decreased intestinal motility as indicators of significant sand accumulation warranting treatment
Key Findings
- •Ultrasonography and radiography grades were significantly associated in detecting sand accumulations
- •Ultrasonography demonstrated 87.5% sensitivity (21/24) and 87.5% specificity (7/8) for sand detection
- •13 of 14 horses (92.9%) with moderate or large ventral sand accumulations on radiography were positive on ultrasonography
- •Small and dorsally located sand accumulations were more difficult to detect ultrasonographically, with only 70% detection rate in small ventral or partial accumulations