Advances in imaging of the equine distal limb: 2017–2022 EVJ, EVE and VRU updates

Abstract

Injuries and diseases of the distal limb constitute the commonest causes of lameness in horses, and diagnostic imaging plays a central role in their diagnosis. There have been tremendous advances in the development and application of diagnostic imaging techniques used to evaluate the distal limbs in the past 15–20 years, with advanced cross-sectional imaging modalities, such as magnetic resonance imaging (MRI) and computed tomography (CT), being increasingly utilised to provide diagnostic information, in combination with the more ‘traditional’ techniques of radiography and ultrasonography. These new imaging techniques do not replace radiography and ultrasonography but complement them – indeed each technique has its own advantages and limitations. Like many advances in veterinary medicine, these imaging modalities have transferred from their use in other areas, including human medicine, to use in animals. The initial reliance on MRI and CT scanners designed for use in people (which generally require the equine patient to be imaged whilst under general anaesthesia) has now evolved into scanners that can be used to image the distal limb in standing horses, thereby increasing their practicality and availability in equine practice. The advanced imaging ‘stable’ of MRI and CT has recently been strengthened by the introduction of positron emission tomography (PET), which will undoubtedly add to and further refine our diagnostic capabilities for conditions of the distal limb in the next 5 years. Equine Veterinary Education (EVJ), Equine Veterinary Journal (EVJ) and Veterinary Radiology and Ultrasound (VRU) have joined forces to publish a virtual issue on advances in diagnostic imaging of the distal limb, highlighting a selection of some of the more interesting and important article published in these three journals over the past 5 years. This is the second joint issue that we have published, following on from the issue that we published in 2016, which reviewed articles focused on imaging of the head and neck. The three guest editors for the current virtual issue were Mathieu Spriet (on behalf of EVJ), Ann Carstens (on behalf of VRU) and Tim Mair (on behalf of EVE). Their challenge was to select ‘articles that give novel important information that is clinically relevant and applicable to the limb of the horse from the metacarpo/tarso-phalangeal joint and distally’. We hope that this virtual issue will provide a useful and informative review of some of the exciting developments in diagnostic imaging of the distal limb that have occurred recently. With the ever-increasing technological improvements and availability of diagnostic imaging equipment, we can look forward to further advances in the coming years, which will continue to contribute to improved equine welfare by assisting in the prevention and treatment of diseases of the distal limbs.