CT - Computed Tomography

Computed Tomography (CT scan) is a very common study used in the U.S. for the work-up of tumors in the liver. The patient will likely have a CT exam sometime during evaluation, either to better define something seen on Ultrasound, or to see something that cannot be evaluated by Ultrasound.

CT uses x-ray to look at the structures inside the body. Like Ultrasound, CT looks at the patient's liver, gallbladder, spleen, pancreas, kidneys and the vessels important to the liver, but also looks at the bowel and any abnormal fluid collections.

CT is a multi-phase scan using oral and intravenous (IV) contrast material (liquid dye). Pictures are taken in three phases:

• Without intravenous contrast
• With intravenous contrast (enhanced imaging) that highlights the arterial system (arterial phase)
• When the contrast is in the venous phase

The patient is asked to drink water, to help image the stomach and small bowel. Some people feel warm when the IV contrast is injected; this is normal. Some patients may be allergic to the CT contrast, and should notify his or her physician before the exam.

As the imaging is performed, the patient is asked to hold his breath while the CT table moves him through the scanner. The pictures are taken at very frequent intervals (thin slices) as the body is moved through the CT scanner. A typical CT scan takes approximately 30 minutes.