Today, equine veterinarians can diagnose and treat disease with more speed and certainty than ever thanks to an array of increasingly sophisticated technologies. The digitization of clinical information has had a profound impact on the quality of veterinary care and how veterinarians consult with one another and communicate information to clients. In today's blog post I will be reviewing some of these technologies in use today.
Anaesthesia: However, for some joints some clinicians prefer to use general anaesthesia. The Hallmarq MRI magnet can be rotated to facilitate this procedure and is especially useful for hock joints. Hallmarq manufactures the only MRI system that allows scans of the equine foot and lower limb in a standing position without requiring general anaesthesia. This unique ability has come about as the result of years of research and development.
Computed Tomography (CT) Computed tomography uses radiographs (X rays) and image processing software to generate three-dimensional images of body structures. "CT allows us to really evaluate bone, because it is still X ray technology," says Pease. Unlike a radiograph, which provides a two-dimensional image, CT displays structures in three dimensions by taking pictures in "slices and CT is very good for visualizing head trauma, dental disease, and nasal problems, which are common in horses " according to Pease. "The structures of the head are difficult to see in two dimensions because there is so much superimposition (anatomical structures located above and beneath each other)."
Magnetic Resonance Imaging (MRI) Magnetic resonance refers to the movement of water molecules in the body (much of the body is water) when they are pulled by an electromagnetic field. An MRI machine consists of a radio frequency transmitter, a magnet, a computer to process images, and a computer monitor on which to view the images. A radio frequency is applied to the magnetic field, which temporarily pushes hydrogen atoms in one direction. When the molecules revert back to their original position, a special antenna (called a coil) detects and records the "spin" of the hydrogen atoms (resonance). Software transforms the resonance data into a digital image that is saved on disk or displayed on a computer screen. Different MRI pictures (called sequences) can be captured to help veterinarians fine-tune their view of anatomical structures; these sequences provide exquisite detail of water and soft tissue.
"MRI has made the most impact on diagnosing problems in the hoof and lower leg," says Pease. "Whenever you have disease or trauma, edema (fluid swelling) is one of the first things that happens. Water is detected as a bright area on an MRI. We can see the soft tissue damage where there might not necessarily be a bone lesion. This helps us diagnose navicular disease and suspensory ligament tears.Scintigraphy With scintigraphy the veterinarian injects a specialized agent into the horse that has small amounts of radioactive material. This agent selectively binds to or is eliminated from specific structures. A special gamma camera detects gamma radiation emissions from the radioactive material and records the images on a computer display or film. Scintigraphy not only helps reveal disease processes but also shows functional information that cannot be detected using other imaging techniques.
"Nuclear medicine is helpful when animals have a low-grade nondescript lameness that is hard to localize," says "For example, when bone is injured, it will heal. But this process may not be severe enough to see on an X ray, though it is still causing pain and lameness. On scintigraphy we can see bone damage and healing, but we don't know exactly how bad it is or why it is damaged--we just know it is a site where bone is undergoing remodeling. We can follow up with radiographs, ultrasound, CT, or MRI depending on how bad the lameness is, to further characterize the problem. Cited on March 20/2012
