Diagnostic sonography, or ultrasound, is an imaging technique that is widely used to examine internal organs for illness or injury. It produces no radiation as with x-ray technology. Sonograms (ultrasound images) are obtained using a small, hand-held probe called a transducer. The transducer is placed on the patient and directed across the skin by a veterinarian to obtain various angles and views of specific organs.
Ultrasound is particularly effective at looking inside solid or fluid-filled structures such as those inside the abdomen or heart (cardiac echo). These are areas in which radiography (x-ray), the traditional imaging mode, is limited in many ways. Ultrasound is also particularly useful when guiding veterinarians in delicate procedures such as fluid drainage or biopsy. Ultrasound is much less effective at imaging bone or the lungs, but fortunately, this is where radiography excels.
The digital images produced by the ultrasound machine are transferred to our PACS (Picture Archiving and Communication System) server so they can be retrieved by any computer in our hospital, or transferred electronically to offsite veterinary specialists for review. Ultrasound is used in conjunction with other diagnostic tools, including a complete physical examination, to aid veterinarians in diagnosis of disease or injury.
In most cases, an ultrasound can be performed without sedation or anesthesia. The patient is placed on its side, stomach or back (depending upon the areas of the body to be viewed) within the confines of a padded ultrasound cradle. Small areas of fur will be clipped by one of two technicians involved with the procedure, in order to make positive contact between the ultrasound transducer and the skin. The veterinarian will then guide the transducer across the areas to be examined, observing and recording specific views, while two technicians assist in comforting the patient.
Sometimes sedation or even general anesthesia may be required to perform an ultrasound, especially in extremely fearful or painful patients, and ultrasound-guided biopsies are always performed under general anesthesia. These patients are usually sent home the same day, following full recovery from the drugs.