Pet Diagnostics

While to you and me the images looks something like static on a TV without a signal, to the trained eye the images show what is happening inside the body and inside the organs being viewed. Subtle changes to an organ like the liver may be an indication of spread of cancer or the valves of the heart may be abnormal and leaking. Ultrasound allows us to see these things. The American College of Veterinary Radiology, the overseeing group for radiology, strongly suggests that ultrasounds be performed by board certified radiologist using high quality ultrasound machines and feels that the quality of the study is very dependent on those two factors.

In most cases, your friend can be awake for the study. It is possible in many cases to use ultrasound to help guide fine-needle aspirates or biopsies of masses or organs under the skin. For these procedures, sedation or anesthesia may be required. Generally speaking, the risk is low for those procedures. Bleeding is the most common side effect and in very rare cases can be life threatening. If your pet has an ultrasound-guided biopsy performed and there was a problem, you might see them become very lethargic, pant more, have a bloated abdomen or pale gums in their mouth. If any of these things are seen, you should contact a veterinarian right away (even if this means the veterinary emergency service if it is after hours).  Results are usually available right away. Ultrasound for dogs and cats is available at Arizona Veterinary Oncology.

Tumors have abnormal blood vessels that are very leaky. We rely on the fact that iodine based contrast agents want to get out of the blood vessels as fast as possible. When viewed on CT scans, the iodine leaks out into the tumor tissue faster than the surrounding tissue and therefore highlights the location and extent of the tumor. Common places that are scanned when pets have cancer include the lungs, the head, the abdomen and the long bones. When we look at the lungs, we can see primary tumors (i.e. tumors that started in the lungs) or we can see metastatic disease (i.e. tumors that have spread from other locations). Many tumors spread to the lungs because that is the first place the tumor cells get stuck in the tiny blood vessels.  When we scan the head, we can see abnormalities such as nasal tumors, oral tumors or sometimes tumors of the brain. Within the abdomen, a CT scan may reveal masses in the various organs and can help us identify the lymph nodes from the back half of the body that might be diseased. For bones, it can sometimes be very difficult on a two-dimensional X-ray to tell if the bone is broken or not. With CT scans, we can make three-dimensional images that help the radiologist get a better look at the bone.

For stereotactic radiotherapy planning, your pet will likely be placed into an immobilizing device prior to the CT scan. This device will allow us to position your pet accurately on the treatment table and mimic the positioning that was used on the CT table. The immobilization device can only be made with your pet anesthetized and must be done at our Gilbert location. If a CT scan or MRI has been performed at a different facility, please be sure to bring a CD containing the images to your appointment. If you would like to pursue stereotactic radiosurgery, we may need to repeat the CT scan with immobilization so we can accurately plan your pet’s treatment.

CT scans can also be used by the surgeons to help plan their approach for surgery. Our surgeons also work closely with the radiologist to try and get as much information as possible prior to your pet being under anesthesia to ensure that the procedure will go as smoothly and safely as possible.

Ask your veterinarian if a CT scan for pets is a good diagnostic test for your friend today.

The contrast can be easily seen on the scan and helps to highlight these structures.

MRI works best for soft tissues (i.e. not bones). Our colleagues that specialize in neurology use MRI scans to look at the brain and spinal cord more than anything else in dogs and cats. This test is very good for finding tumors in those structures. MRI is sensitive enough to tell the difference between a solid tissue, clear fluid (edema) and blood. For radiation treatment planning, we often use a combination of MRI and CT scans (computed tomography) to get the best of both worlds (CT is better for looking at things like bones and air-filled cavities like the lungs). With our advanced treatment planning software, we can fuse the images together and look at the best parts of the MRI and CT at the same time. Surgeons are starting to use MRI in animals just as they do in humans to look at structures like tendons and ligaments, particularly in the knee. At Arizona Veterinary Oncology, we can help coordinate an appointment for you with our colleagues in the Phoenix Valley that offer MRI as a diagnostic test for dogs and cats.