Comparison of cone‐beam and fan‐beam computed tomography and low‐field magnetic resonance imaging for detection of palmar/plantar osteochondral disease in Thoroughbred horses

Background Palmar/plantar osteochondral disease (POD) of the metacarpal/tarsal condyles is a common pathological finding in racehorses. Objective To compare diagnoses, imaging details, and measurements of POD lesions between cone‐beam computed tomography CT (CBCT), fan‐beam CT (FBCT), and low‐field magnetic resonance imaging (MRI) using macroscopic pathology as a gold standard. Study design Cross‐sectional study. Methods Thirty‐five cadaver limbs from 10 horses underwent CBCT, FBCT, MRI, and macroscopic examination. CT and MR images were examined for presence of POD, imaging details of POD, and measurements of POD dimensions and areas. Imaging diagnoses, details, and measurements were compared with macroscopic examination and between modalities. Results Forty‐eight POD lesions were seen over 70 condyles. Compared with macroscopic examination the sensitivity and specificity of diagnosis were 95.8% (CI95 = 88%–99%) and 63.6% (CI95 = 43%–81%) for FBCT, 85.4% (CI95 = 74%–94%) and 81.8% (CI95 = 63%–94%) for CBCT, and 69.0% (CI95 = 54%–82%) and 71.4% (CI95 = 46%–90%) for MRI. Inter‐modality agreement on diagnosis was moderate between CBCT and FBCT (κ = 0.56, p