CT-Based Reference Ranges for Canine Pyloric Thickness: Influence of Body Size and Normalization With Aortic Diameter

Area of Science:

• Veterinary Radiology
• Comparative Pathology
• Diagnostic Imaging

Background:

• Pyloric wall thickness is a key indicator of pyloric pathology in dogs.
• Previous studies had limitations, including small sample sizes and inconsistent measurement techniques.
• Establishing reliable reference ranges for pyloric thickness is essential for accurate diagnosis.

Purpose of the Study:

• To establish body-weight (BW)-specific computed tomography (CT) reference ranges for pyloric thickness in clinically normal dogs.
• To evaluate the relationship between pyloric thickness and BW, age, breed, and sex.
• To assess the utility of the pyloric thickness-to-aortic diameter (P/Ao) ratio as a diagnostic tool.

Main Methods:

• A multicenter retrospective study analyzed CT images from 229 clinically normal dogs.
• Pyloric thickness was measured in both cross-sectional (using multiplanar reconstruction) and transverse planes.
• The P/Ao ratio was calculated, and statistical analyses were performed to assess correlations with various factors.

Main Results:

• Pyloric thickness showed a significant positive correlation with BW, with distinct differences across BW groups.
• No significant associations were found with age, neutering status, or breed (among similar BW).
• The P/Ao ratio was independent of BW, providing a consistent metric across different dog sizes.

Conclusions:

• BW-specific CT reference ranges for pyloric thickness are valuable for routine clinical assessment.
• The BW-independent P/Ao ratio is a practical tool for evaluating pyloric thickness, especially when BW is unknown.
• These findings improve the diagnostic accuracy for canine pyloric diseases.