Texas Equine Veterinary Association

www.texasequineva.com • 25 traditional radiograph practices, it is far more intuitive for the farrier to be able to look at the radiograph and relate it to the foot. 7. Primary Beam Aiming: Now that the feet are placed properly on the blocks, and the calibration object is in place, the generator aiming is next. This is where these views differ the most from traditional foot radiographs. While some foot views are taken to access the distal interphalangeal joint (Figure 5A, C), these farrier-views are more focused on the more distal coffin bone and therefore, use a lower beam height (Figure 5B, D). With proper height foot blocks that have perpendicular surface marker lines, the generator is simply placed on the ground with the crosshair of the generator aligned with the marker for proper orthogonal views (Figure 5E). The acquisition plate is placed with its edge on the ground and up against the radiograph block. With this orientation, the focal beam of the radiograph will orient at the distal margin of the coffin bone, and at approximately the widest point of the foot in each view. Additionally, this orientation will ensure that the beam is perpendicular to the plate and the subject of interest. Of note, this alignment and orientation works best on barefoot and feet shod with traditional shoe and/or pad setups. If the foot has a large package, such as some gaited horses or certain therapeutic packages, the generator beam may need to be elevated Figure 5. Diagram of beam positioning in a high beam lateral radiograph aimed at the distal interphalangeal joint (A), versus a low beam lateral radiograph aimed distal to the coffin bone (B), and the respective radiographs (C, D) in which the blue dot indicates targeted position of primary beam as diagramed by the light blue arrow. (E) Example of beam location and generator and plate positioning for an LM radiograph on an equine foot placed on a radiograph block. A B C D E to achieve proper beam orientation. This can be achieved by placing the generator on a book or board approximately the same thickness as the shoe package, or by simply lifting the generator up, but this latter option may introduce motion artifact. Generator distance from the acquisition plate should be kept consistent. Many of the modern generators have dual lasers to assist with this. In a proper farrier-view LM, both branches of the horseshoe should be superimposed over each other, rendering a more accurate radiograph with which to measure sole depth from the tip of the coffin bone. The difference can be noted in the radiographs of Figure 5. Precise and consistent foot radiographs are essential for farriers and veterinarians alike. Assessment of growth changes, palmar/ plantar angle of P3, the P3-pastern axis, shoe position as it relates to support and breakover as well as the relationship of the solar rim to the ground and pastern and the joint spacing of the coffin and pastern joints is critical for maintaining hoof balance, hoof mass and mechanics of the shoe and lower limb—all of which can be inferred from the precise radiograph. Informative, comparative, and accurate radiographs can only be achieved by employing uniform radiograph acquisition techniques.

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