Computerised tomography is also known as a CT or CAT scan. It uses multiple different x-ray projections from a small x-ray source which rotates around the patient to provide cross sectional images of the body. Computerised post processing is used to create cross sectional images from innumerable x-ray projections.
A CT scan can be used to image any area of the body. It is ideal in imaging the brain, chest, abdomen and bony elements throughout. Multidetector CT allows us rapid image acquisition in a few seconds which allows for good vascular assessment with CT angiography. CT is often used in oncology staging and follow-up. Some specialised CT examinations are also possible specifically for evaluating the colon and coronary arteries.
The patient usually lies supine on a dedicated table which moves in and out of the scanner while the scan is being obtained. It is often helpful to inject iodinated contrast to evaluate enhancement patterns and blood vessels in the areas imaged. The CT itself is a painless examination with the only necessity being that you are completely still whilst imaging. Imaging itself only takes a few seconds per scan. If contrast is needed insertion of a drip will be required. CT uses ionising radiation, but newer technologies are constantly reducing the required dose. We follow a principle of keeping the radiation dose as low as possible to limit any potential risk and also only do scans that are clinically indicated.
Preparation for the CT depends on the area imaged and this information will be given to you when an appointment is made. This may vary from being nil by mouth, to complete bowel preparation, drinking of contrast or use of anti-allergy medication. Blood tests may be required to confirm adequate renal function before contrast is given.
Currently we perform CT scans at our St Anne's and Hilton branches.
Specific CT studies:
- CT Brain
- CT facial bones (incl orbits, sinuses, ears)
- CT Chest (incl. HRCT, CT pulmonary angiogram)
- CT Abdomen and pelvis
- CT spine (incl. CT myelogram)
- CT angiogram
- CT colonography
- CT coronary angiogram
See www.radiologyinfo.org for more information on radiological studies.