COMPUTED TOMOGRAPHY SCANS

COMPUTED TOMOGRAPHY SCANS

(CT, CAT)

'Slice' from a CT scan showing an injury to the left frontal pole (click on picture to see larger version)

Definition

Computed Tomography (CT) is a computer assisted X-ray in which two dimensional pictures are obtained of parts of the body.

What is it used for?

Plain X-rays do not show two or three dimmensional structures well since the shadows of different structures are superimposed on each other. By calculating the density of each layer of tissue that the X-ray passes through, the computer is able to produce a two dimensional view or 'slice' of the area scanned, allowing a better view of the individual structures. This is especially usefull for seeing the brain which not observable on plain xrays as it is surrounded by bone (the skull). CT scanning of the head or back is used to identify any structural abnormality of the tissue including tumors, swelling, strokes, scarring, bleeding, protrusion of discs in the back etc.

Preparation

Preparation depends upon the area being scanned. For CT of the brain and spinal column there is usually no preparation.

Are there side effects?

Sometimes a dye is injected into the veins to help outline blood vessels if these need to be seen. Apart from the needle to inject the dye CT scanning is painless. There are no adverse reactions to the scan, but there can be rare allergic reactions to the dye. If you have a lot of environmental allergies, are allergic to medications or have previously been allergic to X-ray dye, be sure to let your doctor and the CT technologist know before your scan.

R. O'Brien MD

Where are they done?

There are 28 provincial CT scanners in the locations listed below (by district).

East Kootenay

Cranbrook and District Hospital

North Okanagan

Vernon Jubilee Hospital

Thompson

Royal Inland Hospital

South Fraser Valley

Langley/Peace Arch Hospitals (located at Langley)

Surrey Memorial Hospital

Coast Garibaldi

none

Upper Island/Central Coast

Campbell River & Dist Gen Hospital

Northwest

Mills Memorial Hospital

Northern Interior

Prince George Hospital

Vancouver/Richmond

BC Cancer Agency

BC Children's Hospital

Richmond General Hospital

St. Paul's Hospital

University Hospital

Vancouver Hospital

Vancouver Hospital (transferred from Shaughnessy Hosp)

West Kootenay

Trail Regional Hospital

South Okanagan

Kelowna General Hospital

Penticton Hospital

Fraser Valley

Chilliwack General Hospital

MSA General Hospital

Simon Fraser

Burnaby General Hospital

Royal Columbian Hospital

Central Vancouver Island

Nanaimo Regional General Hospital

Cariboo

none

Peace Liard

Dawson Creek & District Hospital

North Shore

Lions Gate Hospital

Capital

Royal Jubilee Hospital

Victoria General Hospital