34th Annual Scientific Meeting proceedings

Objectives:

The use of CT arthrography (CTA) for evaluating cartilage lesions would be beneficial in clinical practice. Since the contrast medium volume used is often driven by operator experience, the aim was to evaluate the minimum volume of iodinated contrast medium for CTA sufficient to identify iatrogenic cartilage lesions in horse fetlock.

Methods:

The study was conducted on ex-vivo 10 distal limbs from adult horses collected at slaughter. Iatrogenic cartilage lesions were arthroscopically made on fetlock, at 5 predetermined locations. Subsequently, CT scans were performed, according to the following protocol: precontrast scan, followed by subsequent scans with incremental volumes of contrast medium, ranging from 5-40 ml (total of 10 scans per fetlock). Then, the cartilage defects were measured during macroscopic examination using a caliper. CTA scans were evaluated by a single operator, and lesions were assessed for presence/absence and volume measures. Data were expressed as median and interquartile values. The association between CT scan assessments and different contrast volumes was examined using the chi-square test. The correlation between CT scans and macroscopic assessments was evaluated using Spearman's coefficient. Significance was set at a p-value < 0.05.

Results:

Twenty milliliters were required to visualize 100% of the lesions, regardless of the location. No correlation was found between the lesions’ volume on macroscopic and CT scan assessment.

Conclusions:

Twenty milliliters of contrast medium was sufficient to correctly identify cartilage lesions on the fetlock articular surface, supporting the conscious use of contrast medium adequate for specific diagnostic purposes.