Computerised Tomography (CT)
Computerised Tomography (CT) is an imaging technique that uses x-rays and a sophisticated computer to produce cross sectional images (slices of information) of the body.
What is a CT scan?
The scanner is a large “doughnut”-shaped machine and patients will move through this gantry as they lay on the scanner bed. A fan-shaped beam of x-rays are produced from inside the gantry, they pass through the patient’s body and are detected on the other side. This information is then sent to a computer which produces numerous images.
At Barnsley Hospital we have two 64-slice CT scanners.
CT is available 24 hours a day, 365 days a year for emergencies.
Access for our outpatient service is between 8:30am to 7:30pm.
Preparation for the scan
Any instructions that are required prior to the patient’s scan will be sent out with their appointment. Patients for CT Colonography or Cardiac CT will be asked to attend for pre-assessment prior to their appointment. Patients may be asked to confirm their appointment by text. Prior to the scan, patients may be required to remove certain clothing or jewellery, and may have to change into a hospital gown.
Women patients and others who menstruate, between the age of 12 and 55, will be asked questions related to their last menstrual period, prior to certain CT examinations.
During the scan
The Radiographer and/or Assistant will explain what is going to happen and in what position we need the patient. The patient will lie on a special table which moves through the gantry during the scan.
If the scan is for the chest or abdomen, the patient will be asked to hold their breath - but this will only be for a few seconds each time the table moves. Patients may hear a whirring noise as the scanner works. For many CT scans an injection of a contrast media is necessary. Prior to any injection patients will be asked whether they have any particular allergies, and whether they are diabetic.
A cannula will be placed into a vein in the patient’s arm or the back of the hand for the fluid to enter the patient’s blood vessels. Some people experience a hot flush-like feeling or a strange taste in their mouth during the injection, but this quickly passes.
If patients have received an injection, they will be asked to remain in the department for 30 minutes after the injection. This is to ensure that they have no side effects from the contrast.
On average scans will last between 10 and 20 minutes.
Can someone stay with me whilst having the scan?
No, due to the exposure to ionising radiation patients cannot be accompanied during the scan. For very small children requiring CT, the Radiographer may allow a parent or carer, to accompany their child. In this scenario the adult will be asked to wear a lead apron to protect them from the radiation.
Are there any risks to having a CT Scan?
CT is an imaging technique that uses x-rays and, therefore, has the usual risks associated with ionising radiation.
The amount of radiation is much more than that of an ordinary x-ray of the abdomen or chest. It is equivalent to the natural background radiation that we all receive from the atmosphere, over a period of between 2 – 8 years.
When will the results be available?
The Radiographer will not be able to give patients their results. Scans will be studied by a Consultant Radiologist who will send the results to the person that referred the patient. This normally takes between 7 and 10 days.
Visit the AccessAble website for accessibility information and directions for attending a Computerised Tomography (CT) scan.