What happens during a CT scan?
When you come to us for a CT scan, you will be asked to lie on a motorized table which slides you through a circular x-ray tube and detectors (looks like a doughnut standing on its side).
The tube rotates and obtains images of thin slices of your body.
The technologist will communicate with you via intercom.
You may be asked to hold your breath at certain points to avoid blurring of images.
What is a CT Scan?
Computed tomography (CT) is a method used to create detailed x-ray images of the body’s internal framework. Images are created of soft tissue, bones, internal organs, arteries and veins within seconds. These images can then be seen in multiple planes and in 3-D.
A CT uses ionizing radiation (similar to x-rays) to create images which is interpreted by the Radiologist. It is a quick imaging modality and is also referred to as the “doughnut” based on the shape of its central console (Foto). The x-ray source and detectors are all housed within the central console. The patient moves through the centre of the console on a mobile bed.
Your doctor will complete a Radiology Request form which is to be brought to our department. The form is very important for Medical Aid approval and needs to accompany you.
The CT department can then be phoned to make a booking and you will be allocated a scheduled date and time.
On the day of your appointment hand your form to our friendly reception staff who will contact your Medical Aid for approval.
If you are a private/cash patient, the reception staff will provide you an estimated price for the examination.
- Referral letter
- Medical aid card
- You may keep your valuables with you, but may be asked to remove jewellery
- If you bring your child:
- Clean set of clothing
- Bottles, milk, nappies, dummies etc
- Favourite soft toy – if applicable
- Treat to enjoy after the scan
Your clinical condition will determine if admission is needed. If you are accompanying your child, you will be escorted to the paediatric ward where an intravenous drip will be placed by one of the qualified pediatric nursing staff.
The hospital porter or staff nurse will accompany you to the CT for your examination.
Here the CT staff will welcome you and ask you to fill in a questionnaire prior to the examination.
The CT Staff will give you a questionnaire to fill in prior to the CT
No sedation needed under normal circumstances.
Sedation may be needed for mentally impaired people. Since scanning time is very short even some of these patients can me managed without sedation.
You are welcome to accompany your child into the CT scanner. Our CT Staff will provide you with a lead apron and thyroid shield to protect against associated radiation.
The examination is usually fairly quick and takes approximately 5-10 minutes.
We follow the RSSA/SASPI imaging guidelines and implement ALARA principles (as low as reasonably achievable) – whilst imaging optimally to ensure a correct diagnosis.
- We follow the RSSA guidelines when administering contrast. We only administer contrast if deemed necessary by the Radiologist.
- This is possible because we always have a Radiologist on site to review the images as they are created.
- The contrast agent we use is Omnipaque 300 or 350 – an iso-osmolar, iodine based, contrast agent – meaning it has the same number of solute particles as normal body fluid/blood, but a higher iodine concentration.
- This contrast agent will be administered by either the radiographer or the qualified nursing sister we have on staff.
- Occasional side effects could include: Flushing feeling, nausea and vomiting, chest tightness and itching.
- The radiographer will alert the Radiologist if the patient experiences any of these side effects and these side effects will be treated individually as they arise
- For more rare severe contrast reactions – bronchospasma and anaphylactic reactions, we have a fully equipped resuscitation trolly on standby within the CT room, as well as a casualty department with emergency personnel to assist us in managing the emergency.
No specific aftercare is needed and you can continue to eat and drink normally after the examination
After the CT scan
Finding out the results
- You may be asked to wait a short time before leaving the CT scanner to make sure you feel well after the examination.
- Specific instructions regarding taking your regular medication (specifically metformin used by type 2 diabetics) over the next few days may be given to you.
- Please note that assessing the detailed images in multiple planes, compiling the report, typing the report and producing your CD with the multiple images may take at least 40 minutes.
- Your referring doctor will assess the images and report and discuss further management with you.
A CT brain is a very quick examination. No preparation is needed. This examination is often done in an emergency setting after trauma since it depicts bleeding in the brain very well. CT is also a very good examination to look for fractures.
CT brain also has an important role to play in the evaluation of stroke patients before thrombolysis is given.
Sometimes intravenous contrast is given during a CT brain to improve visualisation. The contrast is iodine based and you will have to inform the staff if you have an iodine allergy or if you are prone to allergies.
An appointment is needed to do a CT brain. During an emergency your doctor will contact the Radiologist manning the CT station and inform him/her about the emergency. The CT will then be done as soon as possible. Please be considerate in this regard if you have an appointment and have to wait a bit due to an emergency.
CT abdomen and pelvis
There are many different reasons for doing a CT scan of the abdomen and pelvis. The most common indication is abdominal pain with no clear clinical diagnosable cause.
You will need to make an appointment to have an abdominal CT scan. The person making the appointment will ask you why you are having the examination done. She will need this information to plan the examination and to be able to tell you whether any preparation from your side is necessary before the appointment.
Should your referring doctor be suspecting kidney stones, for example, no preparation is needed and it will be a very quick examination. It will be possible to make use of a shorter time slot and you might even be helped sooner!
Otherwise you will have to drink an oral contrast medium to colour the bowel loops and enable the Radiologist to evaluate the bowel loops better. Many different regimes are available to do abdominal examinations. You will be told not to eat from the previous evening, you may drink fluids. The main reason for this is to reduce vomiting during the examination. In an emergency setting the CT abdomen will be done even if you have eaten.
To colour the small and large bowel, oral contrast will be given 2 hours before your booked time slot. If you have an early appointment you may come and fetch your oral contrast on the previous day so you can start consuming it at home. Arrive 20 minutes before the time of your appointment with your referral letter, medical aid card if applicable and ID document. This is to allow enough time to get medical aid approval and complete the patient information form. You may also fill in the form before you arrive. It is available under the “Forms” heading.
During the examination you will most likely be given intravenous contrast agent (i.e. a “colouring” substance give via a drip. Please see questionnaire under “Forms”). It contains iodine and you must inform the staff if you have an iodine allergy. It is also important to tell your referring physician or the booking staff about any allergies so that an alternative examination or other actions may be taken.
CT is a wonderful tool and with proper planning and good communication it can be used to make the most accurate diagnosis.
After the CT scan
Finding out the results
Imaging results are not available online. The main reason for this is security and privacy. Your referring doctor and you will have access to your results. You may also request access to your results by a second physician such as a specialist, if needed.
After the examination you will be asked to wait for your results and a CD with images and a report will be prepared for you. Please consider that the radiologist will have to evaluate the examination, possibly compare it to previous images and then dictate the report to be typed. He/she will then approve the report and send it out. Feel free to ask what the waiting time will be. You may want to come back later or complete other examinations such as drawing blood instead of waiting. Since the amount of images produced during different examinations vary considerably the waiting time will also vary.
Note that we installed a mass digital storage system in 2008. All images and reports done at our practice since 2008 are available at any time. If you need the images or reports at any stage, you may request it. You will have to bring along proof of your identity. If a relative or friend comes to pick up images he/she will need a letter from you requesting the images. These measures are in place to protect our patients’ privacy.