The following CT scans require NO preparation:
- Spine (cervical, thoracic, lumbosacral)
- Extremity (hand, wrist, elbow, shoulder, hip, knee, ankle, foot)
- Kidneys-Ureter-Bladder – “KUB” (looking for kidney stones)
- Sinus/Facial Bones
- Most brain scans
- HRCT Chest (note: If a standard CT chest or CTPA is also requested, these latter two require X-ray dye and the need to fast for 4 hours)
Unless otherwise specified at the time of booking, the following scans need X-ray dye (also known as contrast – see below) and therefore require fasting for 3 hours prior to the examination:
- Abdomen and Pelvis (must also arrive 30 minutes before appointment to drink 1 litre of water).
- CT examinations dedicated to liver (“triphasic liver”), pancreas and kidneys scans
- All Angiograms
If you are to undergo an examination that requires X-ray dye in conjunction with another that does not (for example, a CT of the lumbar spine and CT of the abdomen and pelvis), then you must also fast for 3 hours.
Patients who have poor kidney function (renal impairment) will often not be given contrast so as not to worsen the condition. Diabetic patients who are to undergo a CT with contrast must let the clinic know if they are taking medications for their diabetes, such as Metformin. If this is the case, you will be given special instructions.