While radiographs are like snapshots, ultrasound is like a real-time motion picture. Because it can show internal structures over time and during movement, it is a versatile tool.
In an ultrasound, the veterinarian holds a transducer against your horse's body. The transducer emits high-frequency sound waves. The veterinarian slowly moves the transducer over the area being examined. The sound waves bounce off internal tissues and organs. Tissues of different densities reflect sound waves differently. The transducer separates and identifies the sound waves, 'echoes'. The echoes are then converted into electrical energy. Complex equipment uses them to produce video images - sonograms - on a computer monitor. Sonograms are recorded and can be transmitted much like digital radiographs.
An ultrasound of a mare's reproductive organs can show an embryo at just 12 to 14 days. In contrast, rectal palpation usually cannot detect pregnancy until 30 to 35 days. By day 25, ultrasound can reveal a heartbeat to verify the presence of a viable fetus.
Therefore, while radiographs give us information about bone, ultrasound can answer questions about soft tissue injuries. Ultrasound can also be used to image the heart, lungs, kidneys, liver, spleen, and even the intestines during colic episodes.
Digital radiography is one of several valuable diagnostic tools that allow an equine veterinarian to see inside your horse. Traditional radiography uses film that needs chemical processing. Digital radiography, in contrast, instantly converts x-ray images into digital signals. They can then be displayed on a computer screen.
The digital process results in fewer retakes, meaning less radiation exposure to your horse and to veterinary personnel. Digital radiography's immediate results make for rapid interpretation and action. Your veterinarian can also quickly send the images to other veterinarians anywhere in the world for review via the Internet