Applications

## Positron emission tomography (PET) is a nuclear medicine imaging technique which produces a three-dimensional image or picture of functional processes in the body. Modern scanners include multiple rings of detectors, essentially forming a cylinder. PET is both a medical and research tool. It is used heavily in clinical oncology (medical imaging of tumors and the search for metastases), and for clinical diagnosis of brain diseases. PET is also an important research tool to map normal human brain and heart function.

PET is also used in pre-clinical studies using animals, where it allows repeated investigations into the same subjects. This is particularly valuable in cancer research, as it results in an increase in the statistical quality of the data and substantially reduces the numbers of animals required for a given study.

## Accelerators – Some accelerators which were formerly found only at physics laboratories are now used in hospital-based treatment and diagnostic facilities. Around 9,000 out of 17,000 acceletarors in the world are now ised in the medicine.

## World Wide Web was started in 1989 by Sir Tim Berners-Lee hwo was working at CERN. World Wide Web enabled the spread of information over the Internet through an easy-to-use and flexible format. It played an important role in popularizing use of the Internet.