Highlighting the Benefits of Therapeutic Gardens in Alzheimer's Disease by 18F-FDG Cerebral PET /CT

Inclusion Criteria: * Patient with AD in the mild to moderate stage, followed at the memory and resource center (CMRR) (MMS 15-23) and having had a 18F-FDG PET-CT (Positon emission tomography) scan in routine care having a companion for the duration of the study . * Patient with a neuropsychological assessment (MOCA, DO80, BREF, HAD) of less than 3 months. (If the last neuropsychological assessment dates from more than 3 months, these tests are carried out in routine care during the consultation was proposed and the consent obtained) * Symptomatic treatment of AD (anticholinesterase or memantine) if prescribed, at a stable dose for 1 month, stable psychotropic treatment for 1 month * Person affiliated with a social security scheme or beneficiary of such a scheme. * Patient over 18 years old. * Person received complete information on the organization of the research and having signed their informed consent. Exclusion Criteria: * Patient who did not have biomarkers identified by lumbar puncture * Patient unable to perform a cerebral 18F-FDG PET-CT scan (lying position for more than 20 minutes) * Patient unable to follow the therapeutic program of the garden. * Woman of childbearing age whitout effective contraception. * Pregnant woman or nursing mother. * Person referred to in articles L. 1121-5, L. 1121-7 and L1121-8 of the public health code. * Persons deprived of their liberty by a judicial or administrative decision, persons subject to psychiatric treatment under articles L. 3212-1 and L. 3213-1