Scanning techniques have altered medical knowledge drastically in the 20th century. They are a safe form of non-invasive technology that allow medical staff to: detect disease earlier, understand better how disease spreads, and improve medical care.

X-rays:

Discovered by German scientist Wilhelm Röntgen in 1895
He found radiation would pass through the body at different rates, depending on whether it came across bone or flesh
This resulted in him being able to photograph bones; X-rays were used to investigate broken bones then
During the First World War, mobile X-ray units were used to detect bullets, shrapnel and other items inside the bodies of wounded soldiers
X-rays allowed for quicker and safer surgery and have saved many lives

Ultrasound:

In World War Two, sound waves were used to identify German submarines
The British called this ASDIC, while the Americans labelled it Sonar
After the war, medical personnel realised sound could be used to 'see' inside the human body via high frequency sound waves
This avoided the need to use radiation and allowed for the production of 3-D images
Has been used to obtain images of organs in the body as well as checking the development of unborn babies