Diagnostic Imaging: Inpatient

Computed Tomography (CT) provides high-resolution cross-sectional anatomical images. Anesthetized or sedated patients are placed on the CT table, which moves through a circular opening in the CT scanner (gantry). At the same time, an X-ray tube emits X-rays as it spins 360 degrees inside the gantry. A detector array measures the amount of X-rays that pass through the selected area, generating cross-sectional images. Computed tomography provides more-detailed images of most body parts, but is used most often for disease of the nasal cavity, thorax, abdomen, and certain parts of the musculoskeletal system.

The CT service consists of a Canon Aquilion 64 slice CT scanner with an image anaylysis workstation that allows 2D, 3D, and multiplanar reconstructions that provide a detailed image of the selected anatomy. These images are acquired rapidly, with an average scanning time of 10-20 seconds, so some patients can be scanned under sedation instead of general anesthesia.

Magnetic Resonance Imaging (MRI) is an imaging technique that uses powerful magnets to align hydrogen atoms and radiofrequency waves to systematically alter this alignment. This realignment creates a signal that is detected and transformed into the MRI image. MRI is used for very detailed imaging, especially for imaging soft tissues. The MRI is most commonly used to produce images of the brain and spinal cord, as well as other soft tissues, including tendons and ligaments.

The MRI service utilizes a Philips Intera 1.5T unit, which can be used for small animals and limited exams of horses.

Fluoroscopy uses X-rays to evaluate structures in motion in real time. Examples include evaluation of passage of contrast material through the esophagus and intestines or through the heart and vessels, and tracheal motion. The fluoroscopy room employs a Philips CombiDiagnost fluoroscopy unit.

Nuclear medicine is an imaging technique that involves the injection of a radionuclide and then monitoring the distribution and intensity of the radioactivity within the body with a gamma camera. The process is very sensitive to abnormalities in the bone and is also used to evaluate the liver, kidneys, and thyroid. Small animals and horses can be imaged with this technique. In addition, the Radiology Service provides I-131 therapy for treatment of hyperthyroidism in cats.

Large animals, such as horses, cows, llamas, goats, and pigs, are typically radiographed in a standing position by way of ceiling-mounted X-ray tubes, which are used mainly to image larger body parts. A smaller, mobile X-ray unit is used for the distal extremities. All imaging is digital.

The Radiology Section has two radiographic rooms for small animals (dogs, cats, and pocket pets). While these rooms are primarily used for smaller animals, foals and calves up to 500 lbs. can also be imaged. The general radiographic equipment is a Siemens MultiPro and Philips CombiDiagnost.

Ultrasound uses sound waves to provide a noninvasive image of the abdominal and thoracic organs. Sound waves sent into the body are reflected off an internal tissue interface. Hundreds of these reflected signals create an image of the organ, which can be visualized on the ultrasound machine monitor.

Abnormalities of these organs can be seen and, in most cases, biopsied using ultrasound guidance. Although the abdomen is imaged most frequently with ultrasound, other areas, such as the thorax, eyes, and tendons, can also be examined. Because ultrasound examination is painless, most patients require no sedation or anesthesia and tolerate the procedure well.

The ultrasound service consists of one Philips iU22 unit and one Samsung NeuroLogicaultra unit, which are used for both large and small animal patients. Additional ultrasound machines are located in Community Practice, the ICU, and the large animal barns.