Comparison of cone beam CT and low-field MRI for diagnosing equine foot and pastern lesions

Background: While standing magnetic resonance imaging (sMRI) of the foot has been extensively studied, descriptions of cone beam computed tomography (CBCT) abnormalities in this region are sparse. Objective: This study compares CBCT and sMRI for diagnosing lesions in the equine foot and pastern, aiming to assess the complementarity of these imaging modalities. Study Design: This is a retrospective, descriptive, comparative study. Methods: CBCT and sMRI images of horses that underwent dual imaging between September 2023 and September 2024 were reviewed to evaluate the complementarity of both techniques. Results: Seventy-five feet of 59 horses were included. CBCT and sMRI provided complementary diagnostic information. CBCT was particularly effective in identifying changes in bone structure, soft tissue mineralisation and hoof wall abnormalities. In contrast, sMRI was superior in detecting soft tissue injuries and bone marrow oedema-like signals. Compared with sMRI used alone, CBCT provided additional diagnostic information that enhanced diagnostic accuracy in 71% of cases. Main limitations: No gold standard (i.e., post-mortem findings) was available as the horses were client owned. Conclusions: This study highlights the strengths and limitations of CBCT and sMRI in diagnosing equine foot and pastern pathologies. In most cases, CBCT provided additional information on conditions already visible on sMRI; however, it also detected abnormalities unidentified by sMRI in horses with osteoarthritis, subchondral bone lesions or hoof wall abnormalities.