Preparing for Computed Tomography (CT Scan)

Things to note on the day of appointment

When to arrive

Please arrive 20 minutes before your appointment. In some cases, you are required to drink oral contrast prior to your scan so as to better visualise the bowels. You will be required to consume the contrast at stipulated timings upon your arrival at the department, thus you may need to wait at least 2 hours from your scheduled time when notified.

Blood Test

Creatinine serum blood test might be required to be done before your CT scan examination in order to check for your kidney function. Thus, you may need to wait at least 2 hours from your scheduled time when notified.

Clothing

Depending on the area to be examined, you will be required to change into a hospital gown. We may ask you to remove your jewelry, hair clips, or any other items that may interfere with the scan. A locker will be provided to place your belongings, but it is highly recommended to keep your valuables at home.

Ladies of child bearing age 

Females between 9 to 60 years old, you will be asked for the first day of your last menstrual period (LMP) if your CT procedure is required to include the pelvis region. If necessary, you will be asked to sign a high radiation dose CT consent form. For lower dose CT procedures, you may be asked if there is any possibility that you may be pregnant.

Medical leave

Please note that no medical leave will be issued on the day of exam except for CT Colonography scan. An excuse chit can be given upon request.

Preparation

Depending on the CT procedure, intravenous injection of contrast material may be required to provide information of the blood vessels and organs. An intravenous plug will need to be inserted into a vein in your arm for injection of the contrast material. In line with using any medication or injection, there may be a small chance of developing an allergic reaction to the contrast. Therefore, it is important for you to inform the staff if you have had any form of contrast or allergic reaction prior to this scan.

How to prepare for a CT scan

CT Abdomen / Liver / Pancreas / Chest & Abdomen

• No solid food 4 hours before the scan. Fluid intake is allowed.
• If you are on diabetic medication, stop all diabetic medications on the day of scan.
• If you are on Metformin (Glucophage) : To stop Metformin on the day of the exam and to restart 2 days after of the scan.
  *The used of Iodine based contrast media may result in a transient impairment of renal function and this may precipitate lactic acidosis in diabetics who are taking METFORMIN).
• If you have asthma / previous minor reaction to injection of contrast media, your doctor may have prescribed Prednisolone 30mg. Please take this 12 hours (1st dose) and 2 hours (2nd dose) before your scan. 
  
• If you are on any other prescribed medication, continue your medication as prescribed by your doctor.

CT Chest, Abdomen, Pelvis / Abdomen & Pelvis

• No solid food 4 hours before the scan. Fluid intake is allowed.
• Do not go to the toilet or empty your bladder at least 1 hour before the scan. We need to perform the scan when your bladder is full.
• If you are on diabetic medication, stop all diabetic medications on the day of scan. 
• If you are on Metformin (Glucophage) : To stop Metformin on the day of the exam and to restart 2 days after of the scan.
  *The used of Iodine based contrast media may result in a transient impairment of renal function and this may precipitate lactic acidosis in diabetics who are taking METFORMIN).
• If you have asthma / previous minor reaction to injection of contrast media, your doctor may have prescribed Prednisolone 30mg. Please take this 12 hours (1st dose) and 2 hours (2nd dose) before your scan. 
  
• If you are on any other prescribed medication, continue your medication as prescribed by your doctor.

CT Colonography / Enterography

Preparation instructions will be provided by Radiology staff at the point of appointment. You may also find more information here. 

Other scans not indicated above

No specific preparation is required.

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