There are various methods of examining the body to search for possible diseases. Here are discussed some of them:

X-Rays 

The simple emission of X-rays consists of sending out short electromagnetic waves. After passing through the body, they reach a photographic film and create shadow images. The denser structures, like bone, absorb more X-rays and appear white, whereas the softer tissues appear grey. In other cases, a fluid must be used to fill hollow structures and generate useful images. To examine the digestive tract, for example, a barium sulfate mixture must be ingested.

Contrast is introduced through an enema made of barium. It allows the structures of the digestive tract to be distinguished in detail.

Scanning Methods

The different techniques for exploring the body aim to detect possible anomalies in the organs and tissues. The latest developments, such as magnetic resonance imaging and positron emission tomography, have surpassed classic X-ray methods. It is now possible to obtain detailed images of tissues and of the metabolic activity of tumour cells.

3-D Magnetic Resonance Imaging 

This technique permits greater detail and is used mostly to monitor foetuses.

Ultrasound

A device called a transducer emits extremely high frequency sound waves. The transducer is passed back and forth over the part of the body being examined. The sound waves return to the transducer as an echo and are analyzed by a computer.

Encapsulated Camera

A miniature camera enters the body through a capsule and takes detailed pictures of the digestive tract. It travels using the natural movements of the intestinal walls.

Positron Emission Tomography

This technology enables doctors to obtain detailed information about metabolic issues, such as the cell activity of a tumour. When combined with computerized tomography, it provides high-quality images and advanced knowledge regarding diseases such as cancer. This way, it may be possible to detect an illness before it spreads.

Computerized Tomography 

Computerized tomography (CT) provides information about regions denser than those typically penetrated by X-rays. The tomography covers each millimetre of the body's contour, providing many images of cross sections of the body. By combining these images, a three-dimensional greyscale picture of a particular organ can be obtained.

Magnetic Resonance Imaging

A technique that uses a cylindrical chamber capable of producing a magnetic field 40,000 times stronger than the Earth's. Unlike X-rays, magnetic resonance allows imaging of soft tissues (like fat) and from every angle. It provides the most detailed images and is used most frequently for examining the brain.