Imaging looks inside a whole person to help us understand that person's disease.

Whole body contrast agents are more complicated than staining cells or tissues. Unlike cells and tissue sections, humans really are better doors than windows. Because we’re not very transparent, we cannot use normal light to see inside the body. Instead we must use other forms of light or even sound. Hospitals use radio waves, X-rays, gamma rays and ultrasound to look deep inside patients without having to resort to surgery.

X-ray pictures have been around for a long time.

Radioactive decay is usually seen as pollution. With some clever chemistry it can make pictures of cancer.

X-rays

High energy light beams called X-rays can be used to see through people - generally they work well for hard structures such as bone, but modern X-rays can be very clever.

MRI

Low energy light is usually called radio waves - the breakfast show on your favourite radio station is transmitted on radio-waves. They are also used in MRI scans.

Nuclear Medicine

Nuclear medicine uses very high energy light called gamma rays for PET and SPECT imaging.  Gamma rays are even higher up the energy levels than X-rays.

Ultrasound

High frequency sound can be used; t he image is formed from echoes.  Submarines use sound instead of radar (sonar).  Dolphins, bats, and occasionally people can also use sound to form a picture of the world.