Computed tomography
CT
X-rays produce 2D images of organs, bones and tissues, without superimposition of tissue structures.
During a CT scan, the patient is positioned on a flat bed inside the unit, with a ring-like X-ray tube moving around and along the length of the body. Radiation emitted by the tube is monitored separately. X-ray images are transmitted to a computer showing the body part being scanned. 3D images can also be generated from 2D data.
Our Siemens Emotion 16 CT scanner uses an advanced CARE Dose4D™ radiation reduction system without sacrificing hires quality.
Patients should have some key facts in advance of their CT scan:
A scan usually takes only 2 – 5 minutes, but the process can last up to 30 minutes in total including the setup time.
Procedure
Prior to the procedure, the body part due for scanning must remain uncovered and any metal or other objects are left behind in the changing room.
The patient is positioned on a flat bed and placed in the starting position at the scanner aperture. The tube quickly moves around the patient on the bed, to generate an image of the body part in question, pinpointing the zone to be scanned. While the CT scan is in progress, the patient must remain still and breathe as instructed. Lasting less than a minute, the X-ray tube scans the patient as it rapidly moves down the length of the body.
In some cases, vascular access is required for the intravenous administration of the iodinated contrast agent by means of an infusion pump. Several scans are performed in quick succession lasting just a few minutes. The patient is briefed beforehand about the exact procedure, which is continuously monitored.
Since computer tomography involves X-rays, the patient is exposed to a certain amount of radiation.
When a contrast agent is administered, patients usually experience a hot flush together with a metallic taste in the mouth. However, such side effects soon subside on their own. In rare cases, allergic reactions may occur.
Prior to an appointment for a CT scan involving a contrast medium, the patient must bring a patient screening form with him/her, which has already been filled out by the referring GP. Iodinated contrast media cannot be administered to patients suffering from hyperthyroidism. Any medications containing metformin taken by the patient must be suspended two days before and two days after the CT scan. Since contrast media passes out through the kidneys, good kidney function must be verified beforehand.