Computed Tomography (CT)
Computed Tomography is commonly referred to as a CT scan or CAT
scan. Computed tomography utilizes rotating x-rays around a patient
to make cross-sectional images and is an extremely rapid imaging
modality. Modern CT machines can generate hundreds of these
cross-sectional images in just seconds. Also modern computer
processing can make both two- and three-dimensional reconstructed
images from the acquired CT data. Computed Tomography is an
important part of imaging at the Veterinary Medical Teaching
Hospital at Texas A&M University. Our new Diagnostic Imaging
and Cancer treatment center holds a Siemens Somatom 40 slice
helical CT scanner. The configuration of this machine allows for
imaging of patients that weigh from a few ounces up to nearly 2,000
lbs. Besides dogs, cats, horses and cattle, many other species have
been imaged, some of which include birds, mice, lions, llamas, and
tortoises. Patients must be absolutely still during the CT imaging
process, so general anesthesia (or sometimes heavy sedation in
small animal patients) is utilized along with various foam
positioning devices to assure proper patient positioning. Many
patients that undergo a CT examination also receive intravenous
contrast which acts as a "dye" to highlight blood vessels and the
vascularity of tissues. CT images are acquired for a wide variety
of cases. Most frequently, CT studies are made of spines, skulls,
elbows, as well as a wide variety of tumors. In adult horses, we
can image the limbs, skull, guttural pouches, TMJ's, and often the
first few vertebrae. Computed tomography not only aids in the
diagnosis of disease and patient prognostics, but it is also used
as a tool in the planning of the patient's treatment options.
LEFT: A Bengal tiger is being readied for a CT
exam of the spinal column.
RIGHT: This is a CT image of a cat at the level
of the brain and middle ear. This patient has an infection of the
middle ear cavity (otitis media, arrowhead).
CT scan of a normal yearling horse skull. The teeth, sinus cavities, brain, guttural pouches, TMJ’s, and ear cavities can all be evaluated.
3D rendering of a CT scan of a horse tarsus (hock). This imaging is helpful for surgical planning.
3D rendered CT scan of a cat abdomen, highlighting contrast enhanced structures. The kidneys, spleen, and major vessels (aorta and caudal vena cava) are shown. The curving vessel at the top of the image is an abnormal shunt, directing blood around the liver. This imaging is helpful for surgical planning.