Florbetaben as an Amyloid Plaque Marker in Elderly Patients With Focal or Disseminated Superficial Hemosiderosis

Inclusion Criteria for patients with amyloid cerebral angiopathy with isolated hemosiderosis: * The patient must have given his/her informed and signed consent * The patient must be insured or beneficiary of a health insurance plan * The patient has a single or multiple focal spontaneous hemosiderosis objectified by an MRI * The patient is does not have dementia (Mini Mental State score\> 27) Inclusion Criteria for patients with amyloid cerebral angiopathy with with lobar hematoma(s): * The patient must have given his/her informed and signed consent * The patient must be insured or beneficiary of a health insurance plan * The patient has one or more spontaneous lobar hematomas with or without hemosiderosis objectified by an MRI * The patient is does not have dementia (Mini Mental State score\> 27) Inclusion Criteria for patients with Alzheimer's type dementia without MRI signs in favor of amyloid cerebral angiopathy: * The patient must have given his/her informed and signed consent * The patient must be insured or beneficiary of a health insurance plan * The patient has Alzheimer's dementia (Mini Mental State score \<24) without hemosiderosis or previous lobar hematoma or history of other brain lesion seen on MRI Inclusion Criteria for health volunteers: * The subject must have given his/her informed and signed consent * The subject must be insured or beneficiary of a health insurance plan * Healthy volunteers without cerebral neurological history and with normal MRI * The subject is does not have dementia (Mini Mental State score\> 27) Exclusion Criteria for patients with amyloid cerebral angiopathy with isolated hemosiderosis: * The patient is participating in another interventional study * The patient is in an exclusion period determined by a previous study * The patient is under judicial protection * The subject (next of kin or legal representative) refuses to sign the consent * It is not possible to give the subject or his/her representative informed information * The patient has an contra-indication for performing an MRI * The patient is in the acute phase (the tracer does not bind in cases of large hematoma) Exclusion Criteria for patients with amyloid cerebral angiopathy with with lobar hematoma(s): * The patient is participating in another interventional study * The patient is in an exclusion period determined by a previous study * The patient is under judicial protection * The subject (next of kin or legal representative) refuses to sign the consent * It is not possible to give the subject or his/her representative informed information * The patient has an contra-indication for performing an MRI * The patient is in the acute phase (the tracer does not bind in cases of large hematoma) Exclusion Criteria fpr patients with Alzheimer's type dementia without MRI signs in favor of amyloid cerebral angiopathy: * The patient is participating in another interventional study * The patient is in an exclusion period determined by a previous study * The patient is under judicial protection * The subject (next of kin or legal representative) refuses to sign the consent * It is not possible to give the subject or his/her representative informed information * The patient has an contra-indication for performing an MRI * The patient is in the acute phase (the tracer does not bind in cases of large hematoma) * Haemosiderosis or history of lobar hematoma or other visible cerebral history on MRI Exclusion Criteria for healthy volunteers: * The subject is participating in another interventional study * The subject is in an exclusion period determined by a previous study * The subject is under judicial protection * The subject (next of kin or legal representative) refuses to sign the consent * It is not possible to give the subject or his/her representative informed information * The subject has an contra-indication for performing an MRI * Abnormal MRI The groups will be matched according to sex and age (by increments of 5 years) to the extent possible. Because amyloid cerebral angiopathy is a very rare condition, matching the two factors may be difficult to achieve. We therefore anticipate where appropriate to focus matching on age.