The History of Medical Imaging in Veterinary Medicine
At the beginning of the last century, x-ray technology helped bring medicine out of the Dark Ages. Instead of cutting into a body to visualize basic structure, x-rays could be shot through the body. Some of them would be absorbed by the bones and other tissue, and some would strike the film, creating an image called a radiograph. The first Nobel prize in physics was awarded to Konrad Roentgen for this discovery.
Radiographs are still very useful today in both human and veterinary medicine. In a CT scan, thousands of x-rays are shot through the body at different angles, and a computer calculates and triangulates an image using that data. For some things, like checking the lungs for spreading cancers, CT scans remain the imaging method of choice. Fluoroscopy also uses x-rays, but uses a computer sensor that gives real-time, moving data, instead of film. It is the silent film version of the radiograph’s black & white photo.
In the 1970s, advances in computers (finally calculating fast enough to create a useful image) and superconductors (to make magnetic fields large and powerful enough) led to Magnetic Resonance Imaging (MRI) technology, which catapulted medical imaging into the Space Age with the first human MRI medical scan in 1977.
Just like radiographs, CT scans, and fluoroscopy, MRI images are 2-dimensional representations of the subject being examined. And that is where all similarities end. MRIs use no ionizing radiation, no x-rays are shot through the body. The way in which an MRI creates an image involves placing the body in a magnetic field, which orients all of the atoms in the body so that they are facing one direction. A very brief electromagnetic pulse is applied, and the response of those atoms to this pulse is recorded by a sensor, create the image. Soft tissues like the brain and spinal cord all look pretty much the same on radiographs, because they absorb radiation to the same degree. This problem is overcome with MRI, which is excellent at showing subtleties in soft tissue.
Although MRI technology has been used in veterinary medicine since 1980, in the 80s and 90s it was still new, and not widely available. MRI machines (with their large, powerful magnets) were very large and very, very expensive. They were placed in specially-built trailers, and moved through the country on 18-wheelers, visiting the veterinary schools and a few private specialty clinics on a rotating basis.
Like all other computer- and super-conductor-based technologies, MRI units have gotten smaller, and less expensive with time. It is now feasible to install them in dedicated buildings, and there are now several veterinary hospitals in California with built-in MRI units.
Animal Specialty Group, Los Angeles
ASG is one of these hospitals, providing superb digital imaging technology together with the added benefit of a team of highly skilled specialists who can diagnose and interpret the results of those images. From ultrasonography and fluoroscopy to myelography (radiographs taken after dye has been injected around the spinal cord) and digital radiography to MRI and CT scans, ASG uses a variety of advanced imagine machines and techniques to examine and treat the various conditions that may be affecting your pet. Because they have access to several different imaging methods, they can choose which one is right for your pet based on your pet’s individual circumstance.