CT Scan - How it works?

Enjoy a simple video on how CT Scan works.

ADVANCES IN TECHNOLOGY AND CLINICAL PRACTICE

Today most CT systems are capable of "spiral" (also called "helical") scanning as well as scanning in the formerly more conventional "axial" mode. In addition, many CT systems are capable of imaging multiple slices simultaneously. Such advances allow relatively larger volumes of anatomy to be imaged in relatively less time. Another advancement in the technology is electron beam CT, also known as EBCT. Although the principle of creating cross-sectional images is the same as for conventional CT, whether single- or multi-slice, the EBCT scanner does not require any moving parts to generate the individual "snapshots." As a result, the EBCT scanner allows a quicker image acquisition than conventional CT scanners.

RISK

CT is a very low-risk procedure. 

Patient will be exposed to radiation when undergoing a CT. However, it is a safe level.

The biggest potential risk is if patient need to get a contrast (also called dye) injection. This can help distinguish normal tissues from abnormal tissues. It also helps to distinguish blood vessels from other structures such as lymph nodes.

Like any medication, some people can have a bad reaction to the contrast. The chance of a fatal reaction to the contrast is about 1 in 100,000. Those at increased risk may require special pretreatment and should have the test in a hospital setting. Anyone who has had a prior contrast reaction or severe allergic reaction to other medications, has asthma or emphysema, or has severe heart disease is at increased risk for a contrast reaction and is referred to a hospital x-ray department for the exam.

Any time an injection is done into a vein, there is a risk of the contrast leaking outside of the vein under the skin. If a large amount of contrast leaks under the skin, in rare cases, this can cause the skin to break down.