What is Computerised Tomography?
CT scanning – sometimes called CAT scan – is a diagnostic test that combines special x-ray equipment with sophisticated computers to produce multiple images of the body.
CT imaging is sometimes compared to looking into a loaf of bread by cutting the loaf into thin slices. When the image slices are reassembled by computer software, the result is a very detailed multidimensional view of the body's interior.
CT scans may provide greater clarity and reveal more details than regular x-ray exams.
A major advantage of CT is its ability to image bone, soft tissue and blood vessels all at the same time.
CT In Trauma
CT examinations can quickly and accurately reveal and identify injuries to the brain, spinal colomn, chest, abdomen and pelvis. Perhaps the most frequent use of CT is to detect – or rule out &dash brain and spinal column damage in patients who have been injured. CT is indispensable in the "Golden Hour" after injury to help save lives.
CT Of The Brain
Scanning provides detailed information on head injuries, brain tumors, stroke, bleeding caused by a ruptured or leaking aneurysm and other brain diseases.
CT Of The Sinuses
CT of the sinuses is used to detect the presence of sinusitis, to give information about tumors of the nasal cavity and sinuses and to plan surgery.
CT Of The Chest
Except for the chest x-ray, CT is the most commonly used imaging procedure for evaluating the chest and is often used to further examine abnormalities found on conventional chest x-rays.
CT can help diagnose the cause of clinical signs or symptoms of disease of the chest, such as coughing, shortness of breath, chest pain, or fever.
Chest CT can demonstrate various lung disorders such as pneumonia, tuberculosis, emphysema, bronchiectasis, inflammation or other diseases of the pleura diffuse interstitial lung disease and congenital abnormalities.
Because CT scans are able to detect even very small nodules in the lung, chest CT is especially effective for diagnosing lung cancer at its earliest, most curable stage.
CT Abdomen And Pelvis
This procedure is typically used to help diagnose the cause of abdominal or pelvic pain and diseases of the internal organs, such as abdominal aortic aneurism, appendicitis, diverticulitis, pyelonephritis, renal stones, pancreatitis, liver cirrhosis or inflammatory bowel disease such as ulcerative colitis or Crohn's disease.
It is also used to help diagnose cancers of the colon, liver, kidneys, pancreas and bladder as well as lymphoma.
In the pelvic region, CT scans can help detect and evaluate cysts or tumors of the ovaries.
CT angiography uses contrast material to examine blood vessels in key areas throughout the body.
The procedure is used to identify abnormalities, such as small aneurisms in the brain, atherosclerosis in the carotid artery of the neck, which may limit blood flow to the brain and cause a stroke, identify and evaluate an abdominal aorta aneurism, detect atherosclerotic disease that has narrowed the arteries to the legs, and to examine pulmonary arteries in the lungs to detect pulmonary embolism (blood clots from leg veins).
scanning of the spine is performed to help diagnose spinal pain. Two of the most common causes of spinal pain that may be diagnosed by CT is a herniated intervertebral disk or intervertebral joint disease.
CT is used to detect various types of tumors in the vertebral column, including those that have spread there from another area of the body. Some tumors that arise elsewhere are first identified by finding deposits of metastases in the vertebrae; prostate cancer is an example.
In patients with stenosis of the spinal canal, vertebral fracture, infection or degenerative disease such as arthritis, CT of the spine may provide important information when performed alone or in conjunction with MRI.
CT Cancer Planning
CT is often the preferred method for diagnosing many different cancers since the images allow the physician to confirm the presence of a tumor and measure its size, precise location and the extent of the tumor's involvement with other nearby tissue.
CT guided biopsies may help to confirm the exact histology of a tumor.
CT is indispensable to stage, plan and properly administer radiation treatments for tumors as well as to monitor response to chemotherapy.
Follow up CT may assess whether tumors are responding to treatment.
CT In Pregnancy
Women should always inform their doctor and x ray department if there is any possibility that they may be pregnant. CT scanning is not recommended for pregnant women, unless medically necessary, because of potential risk to the baby. This risk is, however, minimal with head CT scanning.
Nursing mothers should wait for 24 hours after contrast material injection before resuming breast-feeding.
CT In Children
Because children are more sensitive to radiation, they should have a CT exam only if it is essential for making a diagnosis and should not have repeated CT exams unless absolutely necessary. CT scans in children should always be done with low-dose technique. One of the best ways of limiting radiation exposure is to avoid CT scans that are not absolutely necessary.
The new generation scanners are fast enough that children can be scanned without sedation. However, in special cases, sedation may be needed. With pediatric patients, a parent may be allowed in the room but will be required to wear a lead apron to minimize radiation exposure. If you suspect you may be pregnant, however, it would be best for someone else to accompany your child into the scan room.
Your child may be asked not to eat or drink three to six hours beforehand, especially if sedation will be given during the exam.
In general, children who have recently been ill will not be sedated. If this is the case or if you suspect that your child may be getting sick, you should talk to your referring doctor or the radiologist about rescheduling the CT exam.
You should also inform your physician if your child has any allergies, especially to iodine or seafood. The allergy information should also be discussed with the CT radiographer at the time of the CT examination.
Also inform the radiographer of any recent illnesses or other medical conditions your child may have, and if there is a history of heart disease, asthma, diabetes, kidney disease or thyroid problems. Any of these conditions may influence the decision on whether contrast material will be given to your child for the CT examination.
Most children older than six years are able to hold their breath long enough to complete the scan. Younger children may not be able to hold their breath long enough to complete the scan. It is better in these circumstances to have young children breathe quietly and regularly during the scan.
How should I prepare for the CT Scan?
You should wear comfortable, loose-fitting clothing to the exam. You may be given a gown to wear during the procedure. Metal objects including jewelry, eyeglasses, hearing aids and hairpins may affect the CT images and may have to be removed prior to the examination.
You should inform the Radiology Department if you weigh more than 150 kg. The scanner has a maximum weight limit of 150 kg. and a very large patient might not fit into the scanner.
Do not eat or drink anything without the consent of your doctor in charge as there is always a possibility that emergency surgery may follow the CT scan. The Radiologist, in consultation with the referring doctor, will decide on the most appropriate preparation and type of examination for your problem. Most emergency examinations are done without any special preparation.
See Contrast Precautions.
Do not eat or drink anything 4 hours prior to the examination.
See Contrast Precautions.
Do not eat or drink anything 4 hours prior to the examination.
See Contrast Precautions.
Depending on the type of CT exam, you may be asked to take a laxative before the examination to ensure that your bowel is clean and that important information will not be missed. You may also be asked to drink a contrast agent containing barium to aid in the visualization of the stomach and intestines. The Radiology Department will supply you with the specific preparation instructions at the time of making the appointment.
Our Standard Preparation is:
- Laxative (ie. Colo-Prep) when indicated.
- Nothing to eat or drink 4 hours prior to exam.
- 2 Hours prior to exam, drink first bottle of liquid Readi-Cat
- 30 Minutes prior to exam, drink 1/2 of second bottle of Readi-Cat.
- Bring remaining 1/2 bottle of Readi-Cat to exam.
- See Contrast Precautions.
CT EXAMINATIONS WHERE IODINE CONTAINING IV CONTRAST IS NEEDED
Many patients will receive an iodine-based contrast media intravenously during the CT scan. The contrast material significantly enhances the diagnostic quality of a CT scan by helping to evaluate blood vessels and organs such as the liver, kidneys and pancreas. Adverse reactions to contrast media may occur, but are extremely rare with the new low osmolar contrast media. We will, however, do everything possible to avoid complications such as allergic reactions or contrast induced nephropathy (functional damage to kidneys).
Please take a few minutes to carefully read through the following instructions. Do not hesitate to ask if you have any questions.
If you are 60 years or older you must have a blood test showing Urea and Creatinine levels. These tests must have been performed within the last six weeks. The results must be available on the day of your examination.
You should inform your referring doctor as well as the Radiology Department if you have any allergies, especially to iodine or seafood and if there is a history of previous allergic reactions after contrast material. If you have a history of allergy to iodine, the radiologist may advise that you take special medication, such as a steroid, for 24 hours before CT examination to lessen the risk of allergic reaction. Another option is to undergo a different exam that does not call for contrast material injection. The X Ray department will supply you with specific premedication instructions at the time you make an appointment.
Our Standard Premedication for Iodine Allergy is:
- It is crucial that premedication must begin at least 12 hours before the examination.
- 40mg Prednisone (Meticorten) orally 12 hours before the examination.
- 40mg Prednisone (Meticorten) orally 2 hours before the examination.
If you have diabetes, (regardless of age or medication), you must have a blood test showing Urea and Creatinine levels. These tests must have been performed within the last six weeks. The results must be available on the day of the examination. Please note that Glucophage and Metformin should not be taken on the day of, or 48 hours after the examination. Please ask your referring doctor if a renal function test is required before resuming glucophage and metformin. Take all Insulin and non-diabetic medications as prescribed.
OTHER MEDICAL CONDITIONS
You should inform the radiographer or radiologist of any recent illnesses or other medical conditions you may have, such as hyperthyroidism, heart disease, hypertension, asthma, kidney disease or if you only have one kidney. Any of these conditions may influence the decision on whether contrast material for the CT examination will be administered.
How is the CT Scan Performed?
The CT scanner is typically a large, box-like machine with a short tunnel in the center. You will lie on a narrow examination table that slides into and out of this tunnel. Rotating around you is a ring like structure, called a gantry, consisting of the x-ray tube and detectors.
The Radiographer or Sister begins by positioning you on the CT examination table, usually lying flat on your back or less commonly, on your stomach. Straps and pillows may be used to help you maintain the correct position and to hold still during the exam. Depending on the part of the body being scanned, you may be asked to keep your arms above your head.
Next, the table will move quickly through the scanner to determine the correct starting position for the scans. Then, the table will move slowly through the machine as the actual CT scanning is performed. Depending on the type of CT scan, the machine may make several passes.
You may be asked to hold your breath during the scanning to avoid movement artifacts.
You will hear only slight buzzing, clicking and whirring sounds as the CT scanner revolves around you during the imaging process.
You will be alone in the exam room during the CT scan, unless there are special circumstances. However, the radiographer will always be able to see, hear and speak to you at all times.
For some CT exams patients will receive an iodine-based contrast material intravenously (injected into a vein) to enhance visibility in the area of the body being studied.
When the examination is completed, you will be asked to wait until the radiographer verifies that the images are of high enough quality for accurate interpretation.
The radiologist will analyze the images and compile a signed report for your referring doctor, who will discuss the results with you.
A CT scan is usually completed within 60 minutes.
What will I experience during and after the CT Scan?
CT exams are generally painless, fast and easy.
If you are claustrophobic you may receive some medication to help you tolerate the CT scanning procedure.
If oral contrast material is swallowed (i.e. for an abdominal scan), you may find the taste mildly unpleasant; however, most patients can easily tolerate it. You can also expect to experience a sense of abdominal fullness.
If your exam requires IV contrast, you may experience a warm sensation throughout your body and / or a metallic taste in your mouth during administration of contrast. Not everyone experiences these feelings and any sensation you may experience will disappear within a few minutes of the injection.
After a CT exam, you can return to your normal activities.
What will a CT Scan cost?
All fee structures correspond to medical aid tariffs.
Most medical aids cover the costs of CT and MRI procedures. In some instances, a co-payment is required. There may also be a limit to the number of CT and MRI procedures allowable in a year. The medical aids require a referral letter from a specialist and prior authorization must be obtained. You can obtain this authorization yourself if you have all the relevant procedure and tariff codes or you can ask our qualified CT / MRI receptionists to assist you.
Private patients who pay immediately with cash or with Master or Visa Cards will be charged medical aid rates.
The account remains your responsibility.
In the event of non – payment by your medical aid, you will be held liable for the account and it should be paid within 30 days.