Frequently Asked Questions about Computed Tomography (CT) Imaging

Frequently Asked Questions about Computed Tomography (CT) Imaging

• Will the CT Imaging Examination Hurt?
• Is CT Imaging Safe?
• How Long Will the CT Examination Take?
• Do I Need a Referral (Prescription) to Receive an CT Examination?
• Can I Move While I am in the CT Scanner?
• Can I Talk With Anyone During the Scan?
• Can I Bring a Friend or a Relative into the CT Scan Room With Me?
• Do I Need an Injection of Contrast for my CT Exam?
• If I am Nursing an Infant, can I Breast Feed After an Injection?
• Can I have a CT Imaging Exam if I am Pregnant?

Will the CT imaging Examination Hurt?

No, CT imaging itself should cause no pain. CT imaging requires that the patient remain still during the examination. For some patients, keeping still for some time may be uncomfortable. The CT examination itself causes no bodily sensation.

CT imaging examinations that require the patient to receive iodine contrast injection may cause slight, temporary discomfort while the intravenous needle is placed (see below section "do I need an injection?").

Is CT Imaging Safe?

Yes, CT imaging is considered a safe examination. In general, the diagnostic benefit of a CT scan usually outweighs the risk of x-ray radiation exposure or injections of imaging contrast and use of sedatives during the scan. Patients should inform the radiologist or technologist if they have a history of allergies (especially to medications, previous iodine injections, or shellfish), diabetes, asthma, a heart condition, kidney problems, or thyroid conditions.

How Long Will the CT Examination Take?

Most CT departments or centers offer a wide array of computed tomography (CT) imaging examinations. Depending on the type of exam you will receive, the length of the actual procedure will typically be between 10 minutes and 45 minutes. A few involved CT examinations take longer than 45 minutes.

Also, many CT exams require the patient to hold their breath several times. This helps to eliminate blurring from the images, which can be caused by breathing or other patient motion. Please discuss specific questions about the duration of your CT imaging examination with the technologist before your exam.

Do I need a Referral (Prescription) to Receive an CT Examination?

Yes, your doctor must give you a referral (prescription) in order for you to receive a computed tomography (CT) imaging examination. However, CT can often be performed on an outpatient basis without having to admit the patient to the hospital.

Can I Move While I am in the CT Scanner?

You should not move when you are on the CT table and the images are being acquired. It is important that you not move the body part being imaged, for example your head, until the entire CT exam is complete. CT exams of the chest and abdomen require the patient to hold their breath for a short period of time, for example, 10 to 25 seconds. This eliminates blurring in the image caused by breathing or other patient motion.

Can I Talk With Anyone During the CT Scan?

You may talk to the technologists or ask a question in between CT data acquisitions.

Can I Bring a Friend or a Relative into the CT Scan Room With Me?

No, CT uses x-ray and only the person being imaged should be in the CT scanner room during the examination.

Do I Need an Injection of Contrast for my CT Exam?

Not everyone needs an injection for CT imaging. When an contrast injection is needed, a pharmaceutical contrast agent made of iodine is used. This is only done when the radiologist and/or the referring physician have determined that it is necessary for diagnostic purposes. Iodine contrast is used to make specific organs, blood vessels or tissue types "stand out" with more image contrast in the resulting picture. This highlights the structure of the specific organs or vessel to better show the presence of disease or injury. The referring doctor provides the CT center with information about the patient's medical condition and the goal of the CT imaging procedure being ordered (for example, to diagnose cause of intense back pain). The decision to use or not to use an injection of CT contrast is made based on this information and the body part being examined.

If I'm Nursing an Infant, Can I Breast Feed After an Injection of CT Contrast?

Typically, patients are instructed to wait for 24 hours after receiving the CT contrast injection before breast feeding again. Patients may wish to pump breast milk prior to the CT exam and store it for use during this 24-hour period. Always check with the radiologist and the imaging center for their specific recommendations.

Can I Have an CT Imaging Exam if I am Pregnant?

Pregnant woman should not have a CT exam or any x-ray examination, especially if the woman is in her first trimester (first of three-3 month periods of pregnancy). Depending on the condition, there may be other exams available, such as ultrasound, to help diagnose a medical condition. Pregnant women should always inform their imaging technologist or radiologist that they are pregnant, or may be pregnant.

Updated: September 13, 2007