Don’t recommend brain ¹⁸F-FDG PET (positron emission tomography) in the diagnostic investigation of dementia when clinical and neuropsychological assessment, laboratory tests and basic neuroimaging adequately support diagnosis.

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Topic Area


FDG-PET imaging investigates brain glucose hypometabolism. When clinical and neuropsychological assessment, laboratory tests and basic neuroimaging adequately support dementia diagnosis and aetiology, further exams provide inconsistent diagnostic benefits.
On the other hand, this exam is useful in case of atypical presentation, early age at onset or “mixed” clinical manifestations (i.e. combined presence of cognitive, behavioral and/or motor disturbances), with the following recommendations:
– another disease than Alzheimer’s disease suspected (i.e. fronto-temporal dementia), and no movement disorder symptoms observed: ¹⁸F-FDG PET
– cognitive deficits plus movement disorder symptoms (i.e. dementia with Lewy bodies suspected): DaT SPECT, possibly with ¹⁸F-FDG PET
– in case of doubt, an evaluation of dementia expert should precede exams recommendation.


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3. Chételat G, Arbizu J, Barthel H, Garibotto V, Law I, Morbelli S, van de Giessen E, Agosta F, Barkhof F, Brooks DJ, Carrillo MC, Dubois B, Fjell AM, Frisoni GB, Hansson O, Herholz K, Hutton BF, Jack CR Jr, Lammertsma AA, Landau SM, Minoshima S, Nobili F, Nordberg A, Ossenkoppele R, Oyen WJG, Perani D, Rabinovici GD, Scheltens P, Villemagne VL, Zetterberg H, Drzezga A. Amyloid-PET and 18 F-FDG-PET in the diagnostic investigation of Alzheimer's disease and other dementias. Lancet Neurol. 2020 Nov;19(11):951-962. doi: 10.1016/S1474-4422(20)30314-8



Attention. Please note that these items are provided only for information and are not intended as a substitute for consultation with a clinician. Patients with any specific questions about the items on this list or their individual situation should consult their clinician.