About CT

A CT (computed tomography) scan uses special X-ray equipment to take multiple images from different angles around the body. A computer then processes the information from the images and produces an image that shows a cross section of the area being examined. To help visualize the process, imagine looking at one end of a loaf of sliced bread. If you pull a slice out of the loaf, you can see the entire surface of that slice, from the outer crust to the center. The body is seen on CT scan “slices” in a similar way, from the outer skin to the central part of the body. The exam produces multiple slices showing multiple views of the area being examined. The “slices” can be displayed on a video monitor and saved on film for analysis.

A spiral or helical CT involves CT equipment that moves around the patient in a spiral path, allowing continuous data with no gaps between images.

The image can be made even clearer by using a special contrast agent, which can be swallowed as a liquid, injected into a vein, or given as an enema.


15-30 MINUTES including prep time

Why is CT Used?

CT scans can be used to view, monitor, or diagnose

  • muscle and bone disorders, such as tumors and fractures
  • diseases such as cancer or heart disease
  • tumors, infections, or blood clots
  • internal injuries

How to prepare for CT

Wear comfortable, loose clothes. Avoid snaps and zippers. You may be asked to change into a hospital gown. You will be asked to remove metal objects, such as glasses and jewelry that may interfere with the image results. If your exam involves a contrast agent, you will be given specific instructions on preparation. You should inform your doctor or the X-ray technologist (the person performing the exam) if you:

  • are or may be pregnant
  • become anxious in confined spaces
  • are allergic to the contrast agent
  • are allergic to any substance with iodine
  • have been diagnosed heart failure, diabetes, or kidney problems


CT scans involve exposure to radiation in the form of X-rays. The amount of radiation exposure is variable depending upon the scan type (for example, a scan of the brain, lungs, or abdomen) and the scanner type (for example, different models and manufacturers). Because the radiation exposure is variable, the risks are also variable. Silicon Valley MRI & CT has invested in CT equipment that uses the smallest amount of radiation possible on each scan while still providing effective diagnostic results for your physician to understand. 


The results of your exam will be provided to the physician that referred you to Silicon Valley MRI & CT in approximately 24 hours. We only provide these results directly to your physician so that they can assist you to clearly understand the interpretation provided by our radiologist.