Test Details & Preparation
Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, like traditional x-rays, produces multiple images or pictures of the inside of the body. The cross-sectional images generated during a CT scan can be reformatted in multiple planes, and can even generate three-dimensional images. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays, particularly of soft tissues and blood vessels. CT scanning provides more detailed information on head injuries, stroke, brain tumours and other brain diseases than regular radiographs (x-rays).
CT scanning of the head is typically used to detect bleeding, brain injury and skull fractures in patients with head injuries bleeding caused by a ruptured or leaking aneurysm in a patient with a sudden severe headache a blood clot or bleeding within the brain shortly after a patient exhibits symptoms of a stroke a stroke, especially with a new technique called Perfusion CT brain tumours and diseases or malformations of the skull.
CT scanning of the head is also performed to evaluate the extent of bone and soft tissue damage in patients with facial trauma, and planning surgical reconstruction diagnose diseases of the temporal bone on the side of the skull, which may be causing hearing problems determine whether inflammation or other changes are present in the paranasal sinuses, etc.
You should wear comfortable, loose-fitting clothing to your exam. You may be given a gown to wear during the procedure. Metal objects, including jewellery, eyeglasses, dentures and hairpins, may affect the CT images and should be left at home or removed prior to your exam. You may also be asked to remove hearing aids and removable dental work.
You will be asked not to eat or drink anything for a few hours beforehand, as contrast material will be used in your exam. You should inform your physician of all medications you are taking and if you have any allergies.
You may be asked to hold your breath during the scanning. Any motion, whether breathing or body movements, can lead to artifacts on the images. This loss of image quality can resemble the blurring seen on a photograph taken of a moving object. A CT scan of the head is usually completed within 10 minutes.
A radiologist with expertise in supervising and interpreting radiology examinations will analyze the images and send an official report to your primary care physician or physician who referred you for the exam, who will discuss the results with you.