OSF St. Joseph Medical Center

Bloomington, Illinois

Computed Tomography (CT) Scan

A CT scan, also called a CAT scan, is a special type of x-ray that obtains information from different angles around your body. Together with a computer, detailed images and 3D pictures can be created.  

This procedure can be used on many areas of the body including the head, chest, abdomen, and pelvis. The x-ray pictures are very detailed and can be used to study blood vessels, identify tumors and cancers, or guide a surgeon during a biopsy.

Preparing for Your Test


Please follow the instructions given to you at the time of scheduling. There are specific instructions for each type of test ordered.


  • Please bring a complete list of your current medications and dosages.
  • You may take medications as prescribed with small sips of water.

Patient Information

  • If you have a power port, please bring the identification card so we may access this if contrast is needed.
  • Lab work may be required prior to the exam.
  • A blood test to show kidney function is required for patients:
    • Age 65+
    • Who have diabetes
    • With a history of renal transplant or renal failure
    • Who are taking Metformin-based medications
  • Lab work done within 60 days of your scheduled CT scan appointment is valid.


Please inform your doctor if you have an allergy to iodine or X-ray dye. If you have a history of an allergy requiring emergent intervention in the past and you have never had contrast before, please notify X-Ray at (309) 665-4783. You may need to take special medications before having this test.


 Please remove all jewelry prior to your test.

Pregnancy Testing Policy

It is the policy of OSF St. Joseph to verify pregnancy status on all female patients having a CT exam.

This policy is to avoid potential harm to an unborn baby as a result of the radiation or medications given during the exam.

A pregnancy test is required prior to the procedures listed above and should be ordered by your physician if you are a female between the ages of 10 and 55 and have not had a hysterectomy or bilateral oophorectomy. Home pregnancy tests are not acceptable.

If are pregnant, please notify your physician.

What to Expect

Please arrive 30 minutes prior to your scheduled test. If you need blood work before your scan, please check in 60 minutes prior to the time of your scheduled test. Check in through Admitting (Entrance A). Admitting will then direct you to the radiology area.

How Long Will the Exam Take?

Depending on the test, the time can vary from 15 to 45 minutes.

What Will the Exam be Like?

You will be asked to wear clothes with little or no metal on them or you may be asked to change into a hospital gown. You will be escorted to the exam room and placed on the table.

The CT scanner consists of a narrow table and a large donut-shaped ring. For the exam, the table will move through the opening as a series of x-ray beams rotate around you. A computer in the machine will take these pictures. An IV will be initiated to inject the contrast during the procedure. You will need to remain still for the exam, because movement can make the pictures blurry. The scanner is large enough to accommodate 500 pounds.

Results & Recovery

Your test will be read by a Radiologist (a doctor specializing in the Medical Imaging field). The Radiologist will provide a typed report to the doctor who ordered the test. You may make plans with your ordering doctor on how to receive your test results (such as a follow-up doctor’s appointment, calling the doctor’s office, etc.).

After Testing Instructions

If your test included contrast through your vein or you drank an oral prep, you are encouraged to increase your fluid consumption for the next 24 hours to help your body get rid of the contrast and prep. Your urine will not change colors, but the oral prep will cause white or light colored stools as it passes through your system.


To schedule or cancel an appointment, please call (309) 661-5160. Hours are Monday through Friday from 7 a.m. to 7:30 p.m. We do need to have a valid order from a physician to schedule an appointment.