Efficacy and Safety of MNI-672 SPECT for Detection/Exclusion of Cerebral B-amyloid in AD Subjects Compared to HVs.

Healthy Volunteer Inclusion Criteria: * is male and is 20-30 years of age (inclusive) * has no evidence of cognitive impairment as indicated by a clinical dementia rating (CDR, \[Hughes et al. 1993\]) score of 0 (zero) and a score of ≥ 28 in the Mini-Mental Status Examination (MMSE, \[Folstein et al. 1975\]) * has MRI brain scan that has been judged as "normal (age- appropriate)" including ARWMC scale \[Wahlund et al. 2001\] scores supporting the lack of cerebrovascular disease (e.g., a white matter lesion score of 0 or 1 or 2 and a basal ganglia score of 0 or 1) * has no family history of AD defined by more than 1 first-degree relative Alzheimer disease subject inclusion criteria: * is male or female and is ≥ 50 of age, whereby females must be without childbearing potential (confirmed by either: age ≥ 60; or history of surgical sterilization or of hysterectomy, or last spontaneous bleeding at least 2 years prior to the study start) * presents with positive assessment for dementia of Alzheimer's type in accordance with the DSM-IV-TR and probable AD according to the NINCDS-ADRDA criteria and fulfils none of the exclusion criteria of either * does not fulfill the ICC criteria for probable DLB, the NINDS-AIREN for probable Vascular dementia, or the Neary \[Neary et al. 1998\] criteria for FTD * has a CDR \[Hughes et al. 1993\] score of 0.5, 1 or 2 * MRI brain scan findings that do not reveal changes indicative of stroke and/or generalized cerebrovascular disease (e.g., the ARWMC scale) changes limited to: a white matter lesion score of 0 or 1 or 2 and a basal ganglia score of 0 or 1) * has an Amyvid PET scan with moderate to frequent amyloid neuritic plaques based on visual interpretation * has a caregiver who is willing and able to attend study visits and perform the psychometric tests requiring the presence of a caregiver Exclusion Criteria for all subjects: * has any contraindication to MRI examination, e.g. metal implants or phobia * is scheduled for surgery and/or another invasive procedure within the time period of up to 7 days following MNI-672 application * is medically unstable and whose clinical course during the observation period is unpredictable, e.g. patients / volunteers within 14 days of myocardial infarction or stroke, unstable patients / volunteers with previous surgery (within 7 days), patients with advanced heart insufficiency (NYHA stage IV), or with acute renal failure * has a history of exposure to any radiation \>15 mSv/year (e.g. occupational or radiation therapy) * is receiving drug therapy or other treatment that is known to lead to greatly fluctuating values of the hematological or chemical laboratory parameters or to severe side effects (e.g. chemotherapy) * has received anti-amyloid drug therapy * has been previously enrolled in this study or participated in a clinical study involving an investigational pharmaceutical product within 30 days prior to screening, and/or any radiopharmaceutical within 10 radioactive half-lives prior to MNI-672 administration * has a brain tumor or other intracranial lesion, a disturbance of CSF circulation (e.g., normal pressure hydrocephalus) and/or a history of serious head trauma or brain surgery * has a history, physical, laboratory or imaging findings indicative of a significant neurological or psychiatric illness (for patients - other than AD) * has another disease that can cause disturbance of brain function (e.g. vitamin B12 or folic acid deficiency, disturbed thyroid function) * has a history of alcohol or drug abuse