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PET scanner
![2003 PET facility equipped with an ECAT Exact HR+ PET scanner.](/_next/image?url=https%3A%2F%2Fwww.datocms-assets.com%2F117510%2F1722376142-pet-scanner20160520-5431-1q47ttl.jpg%3Fw%3D1228%26h%3D922&w=1920&q=85)
Positron emission tomography (PET) is different to other medical imaging techniques because it requires patients to be injected with a radioactive substance. The images a PET scanner produces shows where in the body the radioactive substance has been transported. This means a PET image is a picture of what is happening metabolically in the body compared to other medical imaging techniques that show the structure or parts of the body.