About CT Scan

What is CT Scan ?

Computed tomography is more commonly known as ‘CT’. It was also known as ‘CAT’ which stands for Computed Axial Tomography.

CT is a way of using X-rays to take detailed pictures or images in very fine slices through the part of the body that the doctor has asked to be investigated - similar to looking at one slice of bread within the whole loaf.

Tomography is actually originated from the Greek words which are ‘tomos’ means slice, and the Greek word ‘graphein’ means write.

These multiple slices of images which are two-dimensional (2D) X-ray images that are generated during a CT scan can be reformatted in multiple planes, and reconstructed into three‐dimensional (3D) images - in other words, many pictures of the same area are taken from many angles and then placed together to produce a 3D image.

2D images of CT Scan of heart

3D images for CT Scan of heart

When CT scanners were first invented, they took one slice at a time and were quite slow when compared to today’s machines. Most modern scanners now take more than one slice at a time.

This may range from 4 to 64 slices and up to 320 slices for the most recent machines. This is referred to as “multislice” or “multidetector” technology and may be abbreviated as MSCT or MDCT.

What CT Scan is used for?

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.

Using specialized equipment and expertise to create and interpret CT scans of the body, radiologists can more easily diagnose problems such as cancer, cardiovascular disease, infectious disease, appendicitis, trauma and musculoskeletal disorders.

 CT can be a life-saving tool for diagnosing illness and injury in both children and adults.

It is also often used to look inside the body before another procedure takes place, such as radiotherapy treatment or a biopsy (where a small sample of tissue is taken so that it can be examined under a microscope).

A radiographer is performing a CT Scan procedure for her patient

How does it work?

CT Scanner produces more detailed image rather than X-ray machine as CT Scanner emits a series of narrow beam compare to diagnostic X-ray machine only emit one way radiation beam.

The X-rays from the CT Scanner will be received by a detector that is located on the opposite side of your body which can see hundreds of different levels of density and also tissues inside a solid organ.

Then, images of the scan will be produced by a computer and can be viewed on a computer monitor, printed on film or transferred to a CD or DVD.

Sometimes a contrast dye is used because it shows up much more clearly on the screen. 

If a 3D image of the abdomen is required the patient may have to drink a barium meal. The barium appears white on the scan as it travels through the digestive system. If images lower down the body are required, such as the rectum, the patient may be given a barium enema. If blood vessel images are the target, the barium will be injected.

Bottles of barium that patients need to drink before undergoes CT procedure

Who does Computed Tomography?

Radiographers or radiation technologists will perform the CT Scan procedure for the patient. The CT scans are interpreted by radiologists who will examine the images taken by the radiographers in great detail to know any pathological conditions of the patient.

Videos

About how CT Scan works

About CT Scan procedure