"Instead of putting them through radiation, PET scans and CT scans, which are very expensive and potentially harmful, we are now looking at noninvasive tests that do the same job, " Topol said.

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People with a rare genetic form of Alzheimer's, whose specific genetic mutations guarantee that they will develop the disease, tended to show signs of amyloid plaques in PET scans and cerebrospinal fluid 10 to 20 years before the onset of symptoms.

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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.

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Lawrence injured his ankle tripping over his pet Labrador last month and underwent further scans on Thursday.

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