For several years now, we have been providing cardiac and abdominal ultrasound for our patients. Ultrasound has helped us diagnose and more thoroughly understand the disease processes occurring in our veterinary patients.
Many people may be familiar with abdominal ultrasound when it is applied to human obstetrics (commonly called a sonogram). But many don’t understand how it works or what we are seeing on the screen. Ultrasound is a series of waves or echoes which penetrate tissue. These echoes appear as a grey scale on the monitor. Depending on the density of the organ you are looking at, these echo waves will either penetrate through, bounce off, or anything in between. Fluid or fluid filled structures appear black because the echo waves pass easily through. Bone and air are impenetrable; the echo waves bounce off these structures and appear white on the screen. Everything else (liver, spleen, kidneys, intestine, urinary bladder) has an “echogenicity” between these. Once we become familiar with what normal abdominal organs look like on ultrasound, we can then use it to find what is abnormal.
With ultrasound we can see what the inside of an organ looks like, and if there are any abnormalities like cysts or masses. These abnormalities can be measured for size and in some instances; an ultrasound guided fine needle aspirate can be done of these abnormalities to obtain a diagnosis. This usually requires a light sedation versus an exploratory abdominal surgery.
In the chest we can evaluate the heart. We can look at the heart’s size as well as its function. We can also see, with the use of color flow Doppler, insufficiencies of the valves of the heart. When we auscult a murmur with a stethoscope during a physical exam, most often this means that one of the valves of the heart is not closing or working properly. We can also measure the thickness of the walls of the heart, its contractility, and see any stenotic (narrowing) or septal defects (holes in the walls of the heart). It’s complicated, and the learning curve has been steep, but the information gathered is much more helpful than a chest radiograph alone. It is a great way to monitor those patients with known heart disease.
So you can see that ultrasound has many applications. We can use it simply to get a sterile urine sample from your pet, or to help diagnose complicated diseases of the heart or abdominal organs. It has been a great diagnostic addition to our practice, one which we used to have to refer our patients to referral centers for. If necessary, we can send the images we have obtained during an ultrasound procedure and have them evaluated by a board certified veterinary radiologist for a small additional fee.