Diagnostic imaging and radiology are an essential part of veterinary medicine. Imaging ties together components of the physical exam and bloodwork to provide the veterinary team with a better idea of what doesn’t look right. The types of images your veterinarian needs depend on your pet’s problem, but they may involve x-ray, ultrasound, CT, MRI, or fluoroscopy. It can be confusing to know why your veterinary team would choose one option over another, so we’re providing a brief overview of each imaging modality, as well as real image examples.
Digital Radiographs (X-Rays)
Digital radiographs, better known as x-rays, are typically used to image bones such as a broken bone or a stress fracture. They can also be used to diagnose conditions like arthritis or kidney stones. Our Dentistry & Oral Surgery Service also frequently uses dental x-rays to fully evaluate a pet’s mouth.
X-rays are widely available in most veterinary clinics and can be performed 24/7 with rapid evaluation – especially important for emergency veterinarians. However, since x-ray images are literal shadows of the internal organs, your veterinarian may also need ultrasound, CT, or MRI to provide a more detailed look at internal structures.
An ultrasound is used to get a live view of what’s going on inside your pet’s body. This imaging option provides superior detail within the abdomen as well as some chest structures like the heart or mediastinum. While an x-ray often only provides an outline or silhouette of abdominal organs, an abdominal ultrasound is more accurate in evaluating their internal structure. However, ultrasound is limited to soft tissue structures and cannot image through air filled structures or bone. Ultrasound is performed frequently in awake pets or pets with varying degrees of sedation.
Abdominal ultrasounds are commonly recommended following abnormal or concerning x-rays to better define a disease process. Common reasons to conduct an ultrasound include concern for gastrointestinal obstruction, chronic inflammatory disease, or cancer, as well as elevated liver or kidney values, anemia, or suspected metabolic conditions. Our board-certified specialists will also often recommend baseline and recheck ultrasounds to monitor response to therapy for cancer or inflammatory diseases.
Ultrasound image of the intestines in a vomiting dog. The smooth oval structure is a squeaker toy that is causing obstruction of the intestines. This foreign body was not visible on x-rays, but the intestinal dilation was concerning and warranted further investigation.
Computed Tomography (CT)
Computed Tomography (CT) is a cross-sectional imaging modality (a slice-like image through the body) allowing for excellent internal visualization of organs. It can be used to image all parts of the body. CT often provides similar information to ultrasound as it relates to the abdomen, but with superior anatomic imaging beyond the abdominal organs. This can include head/neck, thorax, and skeletal system diseases such as inflammatory disease, cancer, or trauma.
CT is frequently recommended when bone evaluation is warranted or in cases where detailed surgical planning is necessary. CT is often performed under general anesthesia, but the scans are typically very quick, which means your pet will be under anesthesia for a shorter period. The machine can even accommodate giant breeds like Great Danes and St. Bernards.
Magnetic Resonance Imaging (MRI)
A High-Field MRI is the preferred imaging diagnostic tool for evaluating the brain and spinal cord due to excellent soft tissue detail and cross-sectional anatomy information. MRI uses a powerful magnetic field, radio frequency pulses, and a computer to produce images of organs and other soft tissues. MRI is performed under general anesthesia.
Our Neurology Service utilizes MRI frequently to diagnose the cause of seizures or behavior change, inflammatory disease, cancer, and back disease such as intervertebral disc disease. Surgeons will also utilize MRI in the case of joints with suspected developmental disease or soft tissue injury (tendon, ligament, muscle).
Fluoroscopy is a form of real-time motion x-ray which is often performed in awake pets to evaluate the airways: suspected tracheal collapse, swallowing disorders, esophageal motility disease, or gastroesophageal reflux.
For airway evaluation, a fluoroscopy can evaluate for evidence of collapse throughout the trachea, bronchi, and nasopharynx (space between the nose and mouth). For esophageal evaluation, often the pet is given different contrast foods to evaluate how he swallows them and what may be abnormal.
Diagnostic imaging detail and accuracy continue to improve as technology evolves, allowing for greater diagnostic detail and accuracy, and helping pets get the care they need sooner. At Animal Emergency & Referral Center of Minnesota, we have the expertise and the technology for high-quality imaging with advanced diagnostic tools onsite at our Oakdale facility. If your pet needs imaging services, ask your family veterinarian for a referral. Note that in an emergency, no appointment is necessary for any imaging needs, but always call ahead.