Doctors can look for indications of the disease using positron emission tomography (PET) scans.

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Once these proteins have been highlighted, they can be seen using a sophisticated positron emission tomography (PET) scans.

BBC: NEWS | Health | Alzheimer's tracked in patients

At the same time, their brains were scanned with positron emission technology (PET), using a radioactive compound that allowed the researchers to visualize where caffeine was going once it arrived in the brain.

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