Computed tomography (Ct-Scan)
Computed Tomography, (CT or CT-scan), is one of the best techniques of modern medical imaging. Non-invasive and painless, it is an examination that combines X-rays and computer technology to produce detailed images of bone cross-sections, soft tissues, air cavities and blood vessels. Computer-assisted calculations allow image reconstruction in all planes and directions.
The CT-scan device uses an X-ray source (similar to ordinary X-ray), but it rotates around the patient, with rays being captured by opposing rotating detectors. Although the scanner emits radiation, the amount emitted during an examination is insignificant. So you do not have to be worried about the effects of radiation when you have a CT-SCAN.
The information is drawn from absorption differences in X-rays between normal tissue and pathological tissue. The greater the difference in absorption, the more the lesion is easily detectable. This is the ideal method for examinations with both a preventive and diagnostic purpose. It allows the viewing of anomalies that are non-detectable in conventional radiology or ultrasound and proves quite useful in the early screening of lung cancer, colon cancer and heart disease. In general, it is the method of choice most used to establish a ”workup” upon discovery of cancer.
Examination by CT-SCAN also brings out issues such as:
- detecting an infection, haemorrhage or tumour
- having a good overview of the body in order to position the organs with respect to each other and determine the path of the blood vessels
- serving as guide in case of punctures of deep organs
An injection of a dye is often necessary to improve the quality of the images of certain parts of the body. If a dye (iodine) is to be used during your examination, you will be asked to arrive at the clinic without having drunk or eaten anything. If you are allergic to iodine, please let us know. We can prescribe tablets for the day before and the day of the test, to ensure that you do not have an allergic reaction. If your previous allergic reactions were severe, we will refrain from injecting you with iodine, in order not to harm you.
During the examination, you will be lying on a motorized table that is part of the scanner. You will be taken inside a ring where the images are taken. It is important not to move during the procedure. If a dye (iodine) is required we will set up an intravenous line before the exam. Once positioned on the motorized table, the technologist will leave the room to perform the various stages of the examination from a console. The technologist remains behind a leaded glass but will always be in contact with you throughout the duration of the examination, giving you the necessary instructions (when to inhale or exhale, etc.). You will be constantly monitored while in the scanner.
During imaging, the table will slide, and the part of the body to be visualized will pass into the tunnel (opening). The tunnel is large enough for your whole body to go through and it is shallow.
Allergy to iodine and/or kidney defects and elevated creatinine
Examination duration 10 to 30 minutes
Examinations NOT COVERED by the RAMQ
Do not drink or eat anything 3 hours before the examination