Computed tomography (CT) is a non-invasive, detailed series of images that combines a series of X-rays taken at different angles to create cross-section images. These images can be viewed in two and three dimensions. Ionising radiation is used to identify abnormalities by producing diagnostic, high-resolution images of the body’s internal structures. CTs are also used as guidance for certain procedures such as biopsies, placement of drains and infiltrations (interventional radiology). 

During CTs patients are required to lie down on a bed in a doughnut-shaped machine with a short tunnel in the centre. Patients need to remain completely still for the duration of the scan because movement will compromise the quality of the scan. Although CTs are painless, patients with injuries or painful clinical conditions may experience some discomfort. Communication with the radiographer is possible via an intercom. 

Some CT scans require oral and/or intravenous contrast. The intravenous contrast is iodine based. Contrast media is used to optimise the visualisation of organs, structures, and vessels in the body. The radiologist or radiographer will insert an intravenous catheter (IV line) into a vein in the patient’s hand or arm. Contrast injections may cause a flush of heat and/or a metallic taste. These sensations usually disappear within a minute or two. At some stages of the scan, patients may be required to breathe as instructed. 

We offer the following imaging services:

  • Abdomen and pelvis
  • Angiograms
  • Bones and joints
  • Brain
  • Cardiac
  • Chest
  • Colonography
  • Enteroclysis
  • Interventional – ablations, core biopsies, fine needle aspirations, pigtail drainages, vertebroplasties, nerve root blocks, and facet infiltrations
  • Musculoskeletal
  • Neck
  • Pelvis
  • Renal tract
  • Sinuses
  • Spine
  • Transcatheter aortic valve implantations (TAVI) planning

Please note:

  • Patients are responsible for obtaining authorisation for radiology procedures. Please contact us for assistance.
  • Emergency cases will be prioritised and may cause some time delays.
  • Women must inform their referring clinician and the radiographer on duty if there is any possibility that they may be pregnant.
  • Patients must bring all previous X-ray images and reports from other institutions on the day of their scan.
  • Depending on the type of CT scan, patients may be asked to change into a hospital gown.
  • At the time of the booking our staff will give patients clear instructions regarding any preparations prior to the scan.
    • Patients must inform the radiographer if they have any allergies. An allergy prep may be required for patients with certain allergies (specifically iodine). Medication will be prescribed to prevent an adverse reaction. This medication must be taken 12 hours prior to the scan and another dose two hours before the scan.
    • Abdomen and pelvis studies require four to six hours fasting. Oral contrast media will have to be collected from our practice before the scan. Patients will be instructed on when to collect and drink the mixture.
    • Colonographies require bowel preps 24 hours prior to the procedure and fasting from 18:00 the night before.
    • Coronary artery scans:
      • No nicotine, caffein and other stimulant drinks such as Red Bull, or soft drinks 24 hours prior to the procedure. Only rooibos tea is permitted.
      • Prior to the scan, patients must only have small, light meals.
      • Avoid peas and bananas.
      • No sleep-averting medication, stimulants, or Viagra 24 hours prior to the procedure.
      • Continue with usual medication but avoid Metformin if diabetic.
    • Enteroclysis studies require four to six hours fasting and patients will have to drink an oral contrast agent on the day of the scan. A nasal tube may sometimes be inserted to administer the fluid.
    • Interventional radiology:
      • Specific blood tests and fasting may be required for interventional radiology procedures.
      • When patients make their booking, they must inform the radiologist or radiographer if they have any allergies or are taking blood thinning medication.
      • Procedures may be done under sedation or local/general anaesthetic for which prior arrangements need to be made. Patients who have had sedation or anaesthesia are not allowed to drive themselves following the procedure and must arrange transport.
      • The type of procedure will determine whether patients need to stay in our recovery room for observation, or be admitted to Milpark Hospital’s day ward, general ward or ICU after the procedure.
      • Radiologists take special care to explain the procedure and the necessary post-care with each patient, ensuring that they are comfortable and understand what it entails.
    • A renal function Urea & Electrolytes (U&E) blood test is necessary for patients requiring intravenous contrast scans. These results must be given to the radiographer prior to the scan.

Frequently asked questions

On average, 15 to 30 minutes. Procedures vary. Interventional procedures can take up to an hour or longer. 

Oral contrast fills the colon and small bowel for better visualisation and delineation between surrounding anatomy. Intravenous contrast enhances the vascular and solid organ structures on the images. It also characterises potential pathology. 

A U&E blood test will confirm that the patient’s kidneys are healthy. Normal kidney function is necessary to use contrast for a scan.