Evaluation of Digital Tomosynthesis for Detecting Articular Cartilage Lesions in Equine Distal Interphalangeal and Metacarpophalangeal Joints: Comparison with Computed Tomography Arthrography

Conventional radiography has limited sensitivity for detecting equine cartilage lesions. This prospective ex vivo study compared digital tomosynthesis (DT), computed tomography (CT), digital tomosynthesis arthrography (DTA), and computed tomography arthrography (CTA) for detecting artificial and naturally occurring partial- and full-thickness cartilage lesions in distal interphalangeal and metacarpophalangeal joints. Sixteen distal forelimbs from nine horses were examined under simulated weight-bearing (SWB) and non-weight-bearing (NWB) conditions. Three blinded observers evaluated 24 regions per limb, using gross examination as the reference standard. Sensitivity, specificity, and agreement were calculated, and mixed-effects logistic regression was performed. Gross examination identified lesions in 141 of 384 regions. Mean sensitivities (95% confidence intervals), reported for SWB and NWB, respectively, were highest for CTA [60.8% (56.7–64.9); 57.0% (53.4–60.5)], followed by DTA [14.7% (10.6–18.7); 29.1% (24.5–33.9)], CT [13.0% (9.3–16.7); 15.4% (12.0–18.8)], and DT [0.5% (0.0–1.0); 1.7% (0.9–2.4)]. Mean specificities ranged from 96.8% (95.3–98.4) to 99.7% (99.3–100.0). For agreement with gross examination, CTA had the highest pooled Cohen’s κ. Contrast medium administration was associated with higher odds of true-positive and lower odds of true-negative classification. Weight-bearing did not consistently improve lesion detection. Clinical performance requires evaluation in living horses.