Preparation
- No food 2 hours prior to your test, however you may have clear liquids up until the time of the exam
- No caffeinated products on the day of test
- Patient will be instructed to hold diabetic medication that contains Metformin for 48 hours following the test. Please check with your doctor prior to testing to see if a substitute is needed.
- Continue taking your medications unless otherwise directed
- Notify your physician before the test if you have had previous history of allergies to the following; CT/IVP contrast or dye, iodine.
- Lab work (Creatinine/GFR) may be required to check renal function prior to test that require IV contrast
- Lab work needs to be completed 7-10 days prior to the day of the exam.
- If labs are required and not completed within 5 days of your exam, we may have to reschedule your appointment.
- It is best to use a Huntsville Hospital lab facility to ensure records are readily available.
- Wear comfortable, loose, two-piece clothing for test
Additional Scan-Specific Instructions
- For CTA of coronary arteries, take medication (if given) as prescribed for heart rate control.
- For CTA of coronary arteries you will need to hold Viagra, Cialis, Levitra, Blue Chew, etc. for 48 hours prior to your appointment.
- For routine CT of abdomen/pelvis, clear liquid diet from midnight the night before test.
Test Description and Procedure
About your test:
Your doctor has ordered a CT scan. This test is performed in a CT scanner using x-rays, and usually IV contrast material. Your scan will be done to examine specific anatomy in your body.
Before your test:
We ask that you wear comfortable, loose, two piece clothing. Clothing with any kind of metal over the part of the body we are scanning will need to be removed. This may include jewelry, buttons, snaps, zippers, and under wire bras. We ask that you avoid any kind of stimulant the day of your test; no coffee, tea, caffeinated soft drinks, nicotine, alcohol, cold medications, etc.. Your physician may give you additional medication for heart rate control if needed.
Please do not eat anything for two hours prior to the exam. It is OK to drink clear liquids on the day of the test up until the time of the exam. Lab work, checking your kidney function, is required for certain CT exams which need to be completed and reviewed as per the directions above. Please notify your doctor or doctor’s nurse if you have had contrast/iodine/IVP dye allergies in the past. You may need pre-medications prior to your CT scan.
When you arrive: You may be asked to complete some paperwork and be asked some questions by the CT staff. After the pre-scan assessment, you will be asked to sign a consent form for completing your test. For most CT scans, an I.V. will be started for use during the test.
The Test:
At the beginning of the test, you will be positioned on the CT table by the technologist and given instructions for the scan. For most CT scans, you will be required to hold your breath while imaging is being performed. The longest you would have to hold your breath is approximately 15 seconds. You may want to practice this at home before your test. This is VERY IMPORTANT as breathing motion can degrade the CT images and make them unusable.
Although we perform many types of CT scans, most of the scans are cardiac or vascular related. These exams require the use of IV contrast to demonstrate the vasculature. When I.V. contrast is administered, you may experience a warm feeling and perhaps a metallic taste. These are normal responses that most patients experience and they subside quickly.
Cardiac CT scans require ECG monitoring during the imaging process. CT scan data is synchronized with the heart rhythm to yield still images of the heart in different phases of the cardiac cycle. The heart rate and stability of the rhythm must be within certain parameters to create scans of diagnostic quality. Sometimes medications may be used, either in pre-scan preparation or during the procedure to optimize the heart rhythm and coronary vasculature.
After the test:
Following the exam, you may be monitored for a few minutes in the discharge area. After vital signs are taken, the I.V. will be removed and post-test instructions will be given by the CT staff. The exam will be reviewed by physicians who specialize in interpretation of CT images. A report of the CT exam will be sent to your physician. You will be contacted by your physician to discuss the results of your exam.
* All procedure times are subject to change based on fluctuations in our schedule and emergency situations involving your physician. It is our intention to begin your procedure at the time listed above.
Last updated on 6/11/2025
